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 irqs-enabled -- see
1054 * rcu_read_unlock_special().
1056 * Since ctx->lock nests under rq->lock we must ensure the entire read
1057 * side critical section has interrupts disabled.
1059 local_irq_save(*flags
);
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(&ctx
->lock
);
1074 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1075 raw_spin_unlock(&ctx
->lock
);
1077 local_irq_restore(*flags
);
1081 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1082 raw_spin_unlock(&ctx
->lock
);
1088 local_irq_restore(*flags
);
1093 * Get the context for a task and increment its pin_count so it
1094 * can't get swapped to another task. This also increments its
1095 * reference count so that the context can't get freed.
1097 static struct perf_event_context
*
1098 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1100 struct perf_event_context
*ctx
;
1101 unsigned long flags
;
1103 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1106 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1111 static void perf_unpin_context(struct perf_event_context
*ctx
)
1113 unsigned long flags
;
1115 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1117 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1121 * Update the record of the current time in a context.
1123 static void update_context_time(struct perf_event_context
*ctx
)
1125 u64 now
= perf_clock();
1127 ctx
->time
+= now
- ctx
->timestamp
;
1128 ctx
->timestamp
= now
;
1131 static u64
perf_event_time(struct perf_event
*event
)
1133 struct perf_event_context
*ctx
= event
->ctx
;
1135 if (is_cgroup_event(event
))
1136 return perf_cgroup_event_time(event
);
1138 return ctx
? ctx
->time
: 0;
1142 * Update the total_time_enabled and total_time_running fields for a event.
1143 * The caller of this function needs to hold the ctx->lock.
1145 static void update_event_times(struct perf_event
*event
)
1147 struct perf_event_context
*ctx
= event
->ctx
;
1150 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1151 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1154 * in cgroup mode, time_enabled represents
1155 * the time the event was enabled AND active
1156 * tasks were in the monitored cgroup. This is
1157 * independent of the activity of the context as
1158 * there may be a mix of cgroup and non-cgroup events.
1160 * That is why we treat cgroup events differently
1163 if (is_cgroup_event(event
))
1164 run_end
= perf_cgroup_event_time(event
);
1165 else if (ctx
->is_active
)
1166 run_end
= ctx
->time
;
1168 run_end
= event
->tstamp_stopped
;
1170 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1172 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1173 run_end
= event
->tstamp_stopped
;
1175 run_end
= perf_event_time(event
);
1177 event
->total_time_running
= run_end
- event
->tstamp_running
;
1182 * Update total_time_enabled and total_time_running for all events in a group.
1184 static void update_group_times(struct perf_event
*leader
)
1186 struct perf_event
*event
;
1188 update_event_times(leader
);
1189 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1190 update_event_times(event
);
1193 static struct list_head
*
1194 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1196 if (event
->attr
.pinned
)
1197 return &ctx
->pinned_groups
;
1199 return &ctx
->flexible_groups
;
1203 * Add a event from the lists for its context.
1204 * Must be called with ctx->mutex and ctx->lock held.
1207 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1209 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1210 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1213 * If we're a stand alone event or group leader, we go to the context
1214 * list, group events are kept attached to the group so that
1215 * perf_group_detach can, at all times, locate all siblings.
1217 if (event
->group_leader
== event
) {
1218 struct list_head
*list
;
1220 if (is_software_event(event
))
1221 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1223 list
= ctx_group_list(event
, ctx
);
1224 list_add_tail(&event
->group_entry
, list
);
1227 if (is_cgroup_event(event
))
1230 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1232 if (event
->attr
.inherit_stat
)
1239 * Initialize event state based on the perf_event_attr::disabled.
1241 static inline void perf_event__state_init(struct perf_event
*event
)
1243 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1244 PERF_EVENT_STATE_INACTIVE
;
1247 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1249 int entry
= sizeof(u64
); /* value */
1253 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1254 size
+= sizeof(u64
);
1256 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1257 size
+= sizeof(u64
);
1259 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1260 entry
+= sizeof(u64
);
1262 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1264 size
+= sizeof(u64
);
1268 event
->read_size
= size
;
1271 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1273 struct perf_sample_data
*data
;
1276 if (sample_type
& PERF_SAMPLE_IP
)
1277 size
+= sizeof(data
->ip
);
1279 if (sample_type
& PERF_SAMPLE_ADDR
)
1280 size
+= sizeof(data
->addr
);
1282 if (sample_type
& PERF_SAMPLE_PERIOD
)
1283 size
+= sizeof(data
->period
);
1285 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1286 size
+= sizeof(data
->weight
);
1288 if (sample_type
& PERF_SAMPLE_READ
)
1289 size
+= event
->read_size
;
1291 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1292 size
+= sizeof(data
->data_src
.val
);
1294 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1295 size
+= sizeof(data
->txn
);
1297 event
->header_size
= size
;
1301 * Called at perf_event creation and when events are attached/detached from a
1304 static void perf_event__header_size(struct perf_event
*event
)
1306 __perf_event_read_size(event
,
1307 event
->group_leader
->nr_siblings
);
1308 __perf_event_header_size(event
, event
->attr
.sample_type
);
1311 static void perf_event__id_header_size(struct perf_event
*event
)
1313 struct perf_sample_data
*data
;
1314 u64 sample_type
= event
->attr
.sample_type
;
1317 if (sample_type
& PERF_SAMPLE_TID
)
1318 size
+= sizeof(data
->tid_entry
);
1320 if (sample_type
& PERF_SAMPLE_TIME
)
1321 size
+= sizeof(data
->time
);
1323 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1324 size
+= sizeof(data
->id
);
1326 if (sample_type
& PERF_SAMPLE_ID
)
1327 size
+= sizeof(data
->id
);
1329 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1330 size
+= sizeof(data
->stream_id
);
1332 if (sample_type
& PERF_SAMPLE_CPU
)
1333 size
+= sizeof(data
->cpu_entry
);
1335 event
->id_header_size
= size
;
1338 static bool perf_event_validate_size(struct perf_event
*event
)
1341 * The values computed here will be over-written when we actually
1344 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1345 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1346 perf_event__id_header_size(event
);
1349 * Sum the lot; should not exceed the 64k limit we have on records.
1350 * Conservative limit to allow for callchains and other variable fields.
1352 if (event
->read_size
+ event
->header_size
+
1353 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1359 static void perf_group_attach(struct perf_event
*event
)
1361 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1364 * We can have double attach due to group movement in perf_event_open.
1366 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1369 event
->attach_state
|= PERF_ATTACH_GROUP
;
1371 if (group_leader
== event
)
1374 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1376 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1377 !is_software_event(event
))
1378 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1380 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1381 group_leader
->nr_siblings
++;
1383 perf_event__header_size(group_leader
);
1385 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1386 perf_event__header_size(pos
);
1390 * Remove a event from the lists for its context.
1391 * Must be called with ctx->mutex and ctx->lock held.
1394 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1396 struct perf_cpu_context
*cpuctx
;
1398 WARN_ON_ONCE(event
->ctx
!= ctx
);
1399 lockdep_assert_held(&ctx
->lock
);
1402 * We can have double detach due to exit/hot-unplug + close.
1404 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1407 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1409 if (is_cgroup_event(event
)) {
1411 cpuctx
= __get_cpu_context(ctx
);
1413 * if there are no more cgroup events
1414 * then cler cgrp to avoid stale pointer
1415 * in update_cgrp_time_from_cpuctx()
1417 if (!ctx
->nr_cgroups
)
1418 cpuctx
->cgrp
= NULL
;
1422 if (event
->attr
.inherit_stat
)
1425 list_del_rcu(&event
->event_entry
);
1427 if (event
->group_leader
== event
)
1428 list_del_init(&event
->group_entry
);
1430 update_group_times(event
);
1433 * If event was in error state, then keep it
1434 * that way, otherwise bogus counts will be
1435 * returned on read(). The only way to get out
1436 * of error state is by explicit re-enabling
1439 if (event
->state
> PERF_EVENT_STATE_OFF
)
1440 event
->state
= PERF_EVENT_STATE_OFF
;
1445 static void perf_group_detach(struct perf_event
*event
)
1447 struct perf_event
*sibling
, *tmp
;
1448 struct list_head
*list
= NULL
;
1451 * We can have double detach due to exit/hot-unplug + close.
1453 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1456 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1459 * If this is a sibling, remove it from its group.
1461 if (event
->group_leader
!= event
) {
1462 list_del_init(&event
->group_entry
);
1463 event
->group_leader
->nr_siblings
--;
1467 if (!list_empty(&event
->group_entry
))
1468 list
= &event
->group_entry
;
1471 * If this was a group event with sibling events then
1472 * upgrade the siblings to singleton events by adding them
1473 * to whatever list we are on.
1475 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1477 list_move_tail(&sibling
->group_entry
, list
);
1478 sibling
->group_leader
= sibling
;
1480 /* Inherit group flags from the previous leader */
1481 sibling
->group_flags
= event
->group_flags
;
1483 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1487 perf_event__header_size(event
->group_leader
);
1489 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1490 perf_event__header_size(tmp
);
1494 * User event without the task.
1496 static bool is_orphaned_event(struct perf_event
*event
)
1498 return event
&& !is_kernel_event(event
) && !event
->owner
;
1502 * Event has a parent but parent's task finished and it's
1503 * alive only because of children holding refference.
1505 static bool is_orphaned_child(struct perf_event
*event
)
1507 return is_orphaned_event(event
->parent
);
1510 static void orphans_remove_work(struct work_struct
*work
);
1512 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1514 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1517 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1519 ctx
->orphans_remove_sched
= true;
1523 static int __init
perf_workqueue_init(void)
1525 perf_wq
= create_singlethread_workqueue("perf");
1526 WARN(!perf_wq
, "failed to create perf workqueue\n");
1527 return perf_wq
? 0 : -1;
1530 core_initcall(perf_workqueue_init
);
1532 static inline int pmu_filter_match(struct perf_event
*event
)
1534 struct pmu
*pmu
= event
->pmu
;
1535 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1539 event_filter_match(struct perf_event
*event
)
1541 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1542 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1546 event_sched_out(struct perf_event
*event
,
1547 struct perf_cpu_context
*cpuctx
,
1548 struct perf_event_context
*ctx
)
1550 u64 tstamp
= perf_event_time(event
);
1553 WARN_ON_ONCE(event
->ctx
!= ctx
);
1554 lockdep_assert_held(&ctx
->lock
);
1557 * An event which could not be activated because of
1558 * filter mismatch still needs to have its timings
1559 * maintained, otherwise bogus information is return
1560 * via read() for time_enabled, time_running:
1562 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1563 && !event_filter_match(event
)) {
1564 delta
= tstamp
- event
->tstamp_stopped
;
1565 event
->tstamp_running
+= delta
;
1566 event
->tstamp_stopped
= tstamp
;
1569 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1572 perf_pmu_disable(event
->pmu
);
1574 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1575 if (event
->pending_disable
) {
1576 event
->pending_disable
= 0;
1577 event
->state
= PERF_EVENT_STATE_OFF
;
1579 event
->tstamp_stopped
= tstamp
;
1580 event
->pmu
->del(event
, 0);
1583 if (!is_software_event(event
))
1584 cpuctx
->active_oncpu
--;
1585 if (!--ctx
->nr_active
)
1586 perf_event_ctx_deactivate(ctx
);
1587 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1589 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1590 cpuctx
->exclusive
= 0;
1592 if (is_orphaned_child(event
))
1593 schedule_orphans_remove(ctx
);
1595 perf_pmu_enable(event
->pmu
);
1599 group_sched_out(struct perf_event
*group_event
,
1600 struct perf_cpu_context
*cpuctx
,
1601 struct perf_event_context
*ctx
)
1603 struct perf_event
*event
;
1604 int state
= group_event
->state
;
1606 event_sched_out(group_event
, cpuctx
, ctx
);
1609 * Schedule out siblings (if any):
1611 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1612 event_sched_out(event
, cpuctx
, ctx
);
1614 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1615 cpuctx
->exclusive
= 0;
1618 struct remove_event
{
1619 struct perf_event
*event
;
1624 * Cross CPU call to remove a performance event
1626 * We disable the event on the hardware level first. After that we
1627 * remove it from the context list.
1629 static int __perf_remove_from_context(void *info
)
1631 struct remove_event
*re
= info
;
1632 struct perf_event
*event
= re
->event
;
1633 struct perf_event_context
*ctx
= event
->ctx
;
1634 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1636 raw_spin_lock(&ctx
->lock
);
1637 event_sched_out(event
, cpuctx
, ctx
);
1638 if (re
->detach_group
)
1639 perf_group_detach(event
);
1640 list_del_event(event
, ctx
);
1641 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1643 cpuctx
->task_ctx
= NULL
;
1645 raw_spin_unlock(&ctx
->lock
);
1652 * Remove the event from a task's (or a CPU's) list of events.
1654 * CPU events are removed with a smp call. For task events we only
1655 * call when the task is on a CPU.
1657 * If event->ctx is a cloned context, callers must make sure that
1658 * every task struct that event->ctx->task could possibly point to
1659 * remains valid. This is OK when called from perf_release since
1660 * that only calls us on the top-level context, which can't be a clone.
1661 * When called from perf_event_exit_task, it's OK because the
1662 * context has been detached from its task.
1664 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1666 struct perf_event_context
*ctx
= event
->ctx
;
1667 struct task_struct
*task
= ctx
->task
;
1668 struct remove_event re
= {
1670 .detach_group
= detach_group
,
1673 lockdep_assert_held(&ctx
->mutex
);
1677 * Per cpu events are removed via an smp call. The removal can
1678 * fail if the CPU is currently offline, but in that case we
1679 * already called __perf_remove_from_context from
1680 * perf_event_exit_cpu.
1682 cpu_function_call(event
->cpu
, __perf_remove_from_context
, &re
);
1687 if (!task_function_call(task
, __perf_remove_from_context
, &re
))
1690 raw_spin_lock_irq(&ctx
->lock
);
1692 * If we failed to find a running task, but find the context active now
1693 * that we've acquired the ctx->lock, retry.
1695 if (ctx
->is_active
) {
1696 raw_spin_unlock_irq(&ctx
->lock
);
1698 * Reload the task pointer, it might have been changed by
1699 * a concurrent perf_event_context_sched_out().
1706 * Since the task isn't running, its safe to remove the event, us
1707 * holding the ctx->lock ensures the task won't get scheduled in.
1710 perf_group_detach(event
);
1711 list_del_event(event
, ctx
);
1712 raw_spin_unlock_irq(&ctx
->lock
);
1716 * Cross CPU call to disable a performance event
1718 int __perf_event_disable(void *info
)
1720 struct perf_event
*event
= info
;
1721 struct perf_event_context
*ctx
= event
->ctx
;
1722 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1725 * If this is a per-task event, need to check whether this
1726 * event's task is the current task on this cpu.
1728 * Can trigger due to concurrent perf_event_context_sched_out()
1729 * flipping contexts around.
1731 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1734 raw_spin_lock(&ctx
->lock
);
1737 * If the event is on, turn it off.
1738 * If it is in error state, leave it in error state.
1740 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1741 update_context_time(ctx
);
1742 update_cgrp_time_from_event(event
);
1743 update_group_times(event
);
1744 if (event
== event
->group_leader
)
1745 group_sched_out(event
, cpuctx
, ctx
);
1747 event_sched_out(event
, cpuctx
, ctx
);
1748 event
->state
= PERF_EVENT_STATE_OFF
;
1751 raw_spin_unlock(&ctx
->lock
);
1759 * If event->ctx is a cloned context, callers must make sure that
1760 * every task struct that event->ctx->task could possibly point to
1761 * remains valid. This condition is satisifed when called through
1762 * perf_event_for_each_child or perf_event_for_each because they
1763 * hold the top-level event's child_mutex, so any descendant that
1764 * goes to exit will block in sync_child_event.
1765 * When called from perf_pending_event it's OK because event->ctx
1766 * is the current context on this CPU and preemption is disabled,
1767 * hence we can't get into perf_event_task_sched_out for this context.
1769 static void _perf_event_disable(struct perf_event
*event
)
1771 struct perf_event_context
*ctx
= event
->ctx
;
1772 struct task_struct
*task
= ctx
->task
;
1776 * Disable the event on the cpu that it's on
1778 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1783 if (!task_function_call(task
, __perf_event_disable
, event
))
1786 raw_spin_lock_irq(&ctx
->lock
);
1788 * If the event is still active, we need to retry the cross-call.
1790 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1791 raw_spin_unlock_irq(&ctx
->lock
);
1793 * Reload the task pointer, it might have been changed by
1794 * a concurrent perf_event_context_sched_out().
1801 * Since we have the lock this context can't be scheduled
1802 * in, so we can change the state safely.
1804 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1805 update_group_times(event
);
1806 event
->state
= PERF_EVENT_STATE_OFF
;
1808 raw_spin_unlock_irq(&ctx
->lock
);
1812 * Strictly speaking kernel users cannot create groups and therefore this
1813 * interface does not need the perf_event_ctx_lock() magic.
1815 void perf_event_disable(struct perf_event
*event
)
1817 struct perf_event_context
*ctx
;
1819 ctx
= perf_event_ctx_lock(event
);
1820 _perf_event_disable(event
);
1821 perf_event_ctx_unlock(event
, ctx
);
1823 EXPORT_SYMBOL_GPL(perf_event_disable
);
1825 static void perf_set_shadow_time(struct perf_event
*event
,
1826 struct perf_event_context
*ctx
,
1830 * use the correct time source for the time snapshot
1832 * We could get by without this by leveraging the
1833 * fact that to get to this function, the caller
1834 * has most likely already called update_context_time()
1835 * and update_cgrp_time_xx() and thus both timestamp
1836 * are identical (or very close). Given that tstamp is,
1837 * already adjusted for cgroup, we could say that:
1838 * tstamp - ctx->timestamp
1840 * tstamp - cgrp->timestamp.
1842 * Then, in perf_output_read(), the calculation would
1843 * work with no changes because:
1844 * - event is guaranteed scheduled in
1845 * - no scheduled out in between
1846 * - thus the timestamp would be the same
1848 * But this is a bit hairy.
1850 * So instead, we have an explicit cgroup call to remain
1851 * within the time time source all along. We believe it
1852 * is cleaner and simpler to understand.
1854 if (is_cgroup_event(event
))
1855 perf_cgroup_set_shadow_time(event
, tstamp
);
1857 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1860 #define MAX_INTERRUPTS (~0ULL)
1862 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1863 static void perf_log_itrace_start(struct perf_event
*event
);
1866 event_sched_in(struct perf_event
*event
,
1867 struct perf_cpu_context
*cpuctx
,
1868 struct perf_event_context
*ctx
)
1870 u64 tstamp
= perf_event_time(event
);
1873 lockdep_assert_held(&ctx
->lock
);
1875 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1878 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1879 event
->oncpu
= smp_processor_id();
1882 * Unthrottle events, since we scheduled we might have missed several
1883 * ticks already, also for a heavily scheduling task there is little
1884 * guarantee it'll get a tick in a timely manner.
1886 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1887 perf_log_throttle(event
, 1);
1888 event
->hw
.interrupts
= 0;
1892 * The new state must be visible before we turn it on in the hardware:
1896 perf_pmu_disable(event
->pmu
);
1898 perf_set_shadow_time(event
, ctx
, tstamp
);
1900 perf_log_itrace_start(event
);
1902 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1903 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1909 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1911 if (!is_software_event(event
))
1912 cpuctx
->active_oncpu
++;
1913 if (!ctx
->nr_active
++)
1914 perf_event_ctx_activate(ctx
);
1915 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1918 if (event
->attr
.exclusive
)
1919 cpuctx
->exclusive
= 1;
1921 if (is_orphaned_child(event
))
1922 schedule_orphans_remove(ctx
);
1925 perf_pmu_enable(event
->pmu
);
1931 group_sched_in(struct perf_event
*group_event
,
1932 struct perf_cpu_context
*cpuctx
,
1933 struct perf_event_context
*ctx
)
1935 struct perf_event
*event
, *partial_group
= NULL
;
1936 struct pmu
*pmu
= ctx
->pmu
;
1937 u64 now
= ctx
->time
;
1938 bool simulate
= false;
1940 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1943 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1945 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1946 pmu
->cancel_txn(pmu
);
1947 perf_mux_hrtimer_restart(cpuctx
);
1952 * Schedule in siblings as one group (if any):
1954 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1955 if (event_sched_in(event
, cpuctx
, ctx
)) {
1956 partial_group
= event
;
1961 if (!pmu
->commit_txn(pmu
))
1966 * Groups can be scheduled in as one unit only, so undo any
1967 * partial group before returning:
1968 * The events up to the failed event are scheduled out normally,
1969 * tstamp_stopped will be updated.
1971 * The failed events and the remaining siblings need to have
1972 * their timings updated as if they had gone thru event_sched_in()
1973 * and event_sched_out(). This is required to get consistent timings
1974 * across the group. This also takes care of the case where the group
1975 * could never be scheduled by ensuring tstamp_stopped is set to mark
1976 * the time the event was actually stopped, such that time delta
1977 * calculation in update_event_times() is correct.
1979 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1980 if (event
== partial_group
)
1984 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1985 event
->tstamp_stopped
= now
;
1987 event_sched_out(event
, cpuctx
, ctx
);
1990 event_sched_out(group_event
, cpuctx
, ctx
);
1992 pmu
->cancel_txn(pmu
);
1994 perf_mux_hrtimer_restart(cpuctx
);
2000 * Work out whether we can put this event group on the CPU now.
2002 static int group_can_go_on(struct perf_event
*event
,
2003 struct perf_cpu_context
*cpuctx
,
2007 * Groups consisting entirely of software events can always go on.
2009 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2012 * If an exclusive group is already on, no other hardware
2015 if (cpuctx
->exclusive
)
2018 * If this group is exclusive and there are already
2019 * events on the CPU, it can't go on.
2021 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2024 * Otherwise, try to add it if all previous groups were able
2030 static void add_event_to_ctx(struct perf_event
*event
,
2031 struct perf_event_context
*ctx
)
2033 u64 tstamp
= perf_event_time(event
);
2035 list_add_event(event
, ctx
);
2036 perf_group_attach(event
);
2037 event
->tstamp_enabled
= tstamp
;
2038 event
->tstamp_running
= tstamp
;
2039 event
->tstamp_stopped
= tstamp
;
2042 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
2044 ctx_sched_in(struct perf_event_context
*ctx
,
2045 struct perf_cpu_context
*cpuctx
,
2046 enum event_type_t event_type
,
2047 struct task_struct
*task
);
2049 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2050 struct perf_event_context
*ctx
,
2051 struct task_struct
*task
)
2053 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2055 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2056 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2058 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2062 * Cross CPU call to install and enable a performance event
2064 * Must be called with ctx->mutex held
2066 static int __perf_install_in_context(void *info
)
2068 struct perf_event
*event
= info
;
2069 struct perf_event_context
*ctx
= event
->ctx
;
2070 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2071 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2072 struct task_struct
*task
= current
;
2074 perf_ctx_lock(cpuctx
, task_ctx
);
2075 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2078 * If there was an active task_ctx schedule it out.
2081 task_ctx_sched_out(task_ctx
);
2084 * If the context we're installing events in is not the
2085 * active task_ctx, flip them.
2087 if (ctx
->task
&& task_ctx
!= ctx
) {
2089 raw_spin_unlock(&task_ctx
->lock
);
2090 raw_spin_lock(&ctx
->lock
);
2095 cpuctx
->task_ctx
= task_ctx
;
2096 task
= task_ctx
->task
;
2099 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2101 update_context_time(ctx
);
2103 * update cgrp time only if current cgrp
2104 * matches event->cgrp. Must be done before
2105 * calling add_event_to_ctx()
2107 update_cgrp_time_from_event(event
);
2109 add_event_to_ctx(event
, ctx
);
2112 * Schedule everything back in
2114 perf_event_sched_in(cpuctx
, task_ctx
, task
);
2116 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2117 perf_ctx_unlock(cpuctx
, task_ctx
);
2123 * Attach a performance event to a context
2125 * First we add the event to the list with the hardware enable bit
2126 * in event->hw_config cleared.
2128 * If the event is attached to a task which is on a CPU we use a smp
2129 * call to enable it in the task context. The task might have been
2130 * scheduled away, but we check this in the smp call again.
2133 perf_install_in_context(struct perf_event_context
*ctx
,
2134 struct perf_event
*event
,
2137 struct task_struct
*task
= ctx
->task
;
2139 lockdep_assert_held(&ctx
->mutex
);
2142 if (event
->cpu
!= -1)
2147 * Per cpu events are installed via an smp call and
2148 * the install is always successful.
2150 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2155 if (!task_function_call(task
, __perf_install_in_context
, event
))
2158 raw_spin_lock_irq(&ctx
->lock
);
2160 * If we failed to find a running task, but find the context active now
2161 * that we've acquired the ctx->lock, retry.
2163 if (ctx
->is_active
) {
2164 raw_spin_unlock_irq(&ctx
->lock
);
2166 * Reload the task pointer, it might have been changed by
2167 * a concurrent perf_event_context_sched_out().
2174 * Since the task isn't running, its safe to add the event, us holding
2175 * the ctx->lock ensures the task won't get scheduled in.
2177 add_event_to_ctx(event
, ctx
);
2178 raw_spin_unlock_irq(&ctx
->lock
);
2182 * Put a event into inactive state and update time fields.
2183 * Enabling the leader of a group effectively enables all
2184 * the group members that aren't explicitly disabled, so we
2185 * have to update their ->tstamp_enabled also.
2186 * Note: this works for group members as well as group leaders
2187 * since the non-leader members' sibling_lists will be empty.
2189 static void __perf_event_mark_enabled(struct perf_event
*event
)
2191 struct perf_event
*sub
;
2192 u64 tstamp
= perf_event_time(event
);
2194 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2195 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2196 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2197 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2198 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2203 * Cross CPU call to enable a performance event
2205 static int __perf_event_enable(void *info
)
2207 struct perf_event
*event
= info
;
2208 struct perf_event_context
*ctx
= event
->ctx
;
2209 struct perf_event
*leader
= event
->group_leader
;
2210 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2214 * There's a time window between 'ctx->is_active' check
2215 * in perf_event_enable function and this place having:
2217 * - ctx->lock unlocked
2219 * where the task could be killed and 'ctx' deactivated
2220 * by perf_event_exit_task.
2222 if (!ctx
->is_active
)
2225 raw_spin_lock(&ctx
->lock
);
2226 update_context_time(ctx
);
2228 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2232 * set current task's cgroup time reference point
2234 perf_cgroup_set_timestamp(current
, ctx
);
2236 __perf_event_mark_enabled(event
);
2238 if (!event_filter_match(event
)) {
2239 if (is_cgroup_event(event
))
2240 perf_cgroup_defer_enabled(event
);
2245 * If the event is in a group and isn't the group leader,
2246 * then don't put it on unless the group is on.
2248 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2251 if (!group_can_go_on(event
, cpuctx
, 1)) {
2254 if (event
== leader
)
2255 err
= group_sched_in(event
, cpuctx
, ctx
);
2257 err
= event_sched_in(event
, cpuctx
, ctx
);
2262 * If this event can't go on and it's part of a
2263 * group, then the whole group has to come off.
2265 if (leader
!= event
) {
2266 group_sched_out(leader
, cpuctx
, ctx
);
2267 perf_mux_hrtimer_restart(cpuctx
);
2269 if (leader
->attr
.pinned
) {
2270 update_group_times(leader
);
2271 leader
->state
= PERF_EVENT_STATE_ERROR
;
2276 raw_spin_unlock(&ctx
->lock
);
2284 * If event->ctx is a cloned context, callers must make sure that
2285 * every task struct that event->ctx->task could possibly point to
2286 * remains valid. This condition is satisfied when called through
2287 * perf_event_for_each_child or perf_event_for_each as described
2288 * for perf_event_disable.
2290 static void _perf_event_enable(struct perf_event
*event
)
2292 struct perf_event_context
*ctx
= event
->ctx
;
2293 struct task_struct
*task
= ctx
->task
;
2297 * Enable the event on the cpu that it's on
2299 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2303 raw_spin_lock_irq(&ctx
->lock
);
2304 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2308 * If the event is in error state, clear that first.
2309 * That way, if we see the event in error state below, we
2310 * know that it has gone back into error state, as distinct
2311 * from the task having been scheduled away before the
2312 * cross-call arrived.
2314 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2315 event
->state
= PERF_EVENT_STATE_OFF
;
2318 if (!ctx
->is_active
) {
2319 __perf_event_mark_enabled(event
);
2323 raw_spin_unlock_irq(&ctx
->lock
);
2325 if (!task_function_call(task
, __perf_event_enable
, event
))
2328 raw_spin_lock_irq(&ctx
->lock
);
2331 * If the context is active and the event is still off,
2332 * we need to retry the cross-call.
2334 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2336 * task could have been flipped by a concurrent
2337 * perf_event_context_sched_out()
2344 raw_spin_unlock_irq(&ctx
->lock
);
2348 * See perf_event_disable();
2350 void perf_event_enable(struct perf_event
*event
)
2352 struct perf_event_context
*ctx
;
2354 ctx
= perf_event_ctx_lock(event
);
2355 _perf_event_enable(event
);
2356 perf_event_ctx_unlock(event
, ctx
);
2358 EXPORT_SYMBOL_GPL(perf_event_enable
);
2360 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2363 * not supported on inherited events
2365 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2368 atomic_add(refresh
, &event
->event_limit
);
2369 _perf_event_enable(event
);
2375 * See perf_event_disable()
2377 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2379 struct perf_event_context
*ctx
;
2382 ctx
= perf_event_ctx_lock(event
);
2383 ret
= _perf_event_refresh(event
, refresh
);
2384 perf_event_ctx_unlock(event
, ctx
);
2388 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2390 static void ctx_sched_out(struct perf_event_context
*ctx
,
2391 struct perf_cpu_context
*cpuctx
,
2392 enum event_type_t event_type
)
2394 struct perf_event
*event
;
2395 int is_active
= ctx
->is_active
;
2397 ctx
->is_active
&= ~event_type
;
2398 if (likely(!ctx
->nr_events
))
2401 update_context_time(ctx
);
2402 update_cgrp_time_from_cpuctx(cpuctx
);
2403 if (!ctx
->nr_active
)
2406 perf_pmu_disable(ctx
->pmu
);
2407 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2408 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2409 group_sched_out(event
, cpuctx
, ctx
);
2412 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2413 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2414 group_sched_out(event
, cpuctx
, ctx
);
2416 perf_pmu_enable(ctx
->pmu
);
2420 * Test whether two contexts are equivalent, i.e. whether they have both been
2421 * cloned from the same version of the same context.
2423 * Equivalence is measured using a generation number in the context that is
2424 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2425 * and list_del_event().
2427 static int context_equiv(struct perf_event_context
*ctx1
,
2428 struct perf_event_context
*ctx2
)
2430 lockdep_assert_held(&ctx1
->lock
);
2431 lockdep_assert_held(&ctx2
->lock
);
2433 /* Pinning disables the swap optimization */
2434 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2437 /* If ctx1 is the parent of ctx2 */
2438 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2441 /* If ctx2 is the parent of ctx1 */
2442 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2446 * If ctx1 and ctx2 have the same parent; we flatten the parent
2447 * hierarchy, see perf_event_init_context().
2449 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2450 ctx1
->parent_gen
== ctx2
->parent_gen
)
2457 static void __perf_event_sync_stat(struct perf_event
*event
,
2458 struct perf_event
*next_event
)
2462 if (!event
->attr
.inherit_stat
)
2466 * Update the event value, we cannot use perf_event_read()
2467 * because we're in the middle of a context switch and have IRQs
2468 * disabled, which upsets smp_call_function_single(), however
2469 * we know the event must be on the current CPU, therefore we
2470 * don't need to use it.
2472 switch (event
->state
) {
2473 case PERF_EVENT_STATE_ACTIVE
:
2474 event
->pmu
->read(event
);
2477 case PERF_EVENT_STATE_INACTIVE
:
2478 update_event_times(event
);
2486 * In order to keep per-task stats reliable we need to flip the event
2487 * values when we flip the contexts.
2489 value
= local64_read(&next_event
->count
);
2490 value
= local64_xchg(&event
->count
, value
);
2491 local64_set(&next_event
->count
, value
);
2493 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2494 swap(event
->total_time_running
, next_event
->total_time_running
);
2497 * Since we swizzled the values, update the user visible data too.
2499 perf_event_update_userpage(event
);
2500 perf_event_update_userpage(next_event
);
2503 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2504 struct perf_event_context
*next_ctx
)
2506 struct perf_event
*event
, *next_event
;
2511 update_context_time(ctx
);
2513 event
= list_first_entry(&ctx
->event_list
,
2514 struct perf_event
, event_entry
);
2516 next_event
= list_first_entry(&next_ctx
->event_list
,
2517 struct perf_event
, event_entry
);
2519 while (&event
->event_entry
!= &ctx
->event_list
&&
2520 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2522 __perf_event_sync_stat(event
, next_event
);
2524 event
= list_next_entry(event
, event_entry
);
2525 next_event
= list_next_entry(next_event
, event_entry
);
2529 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2530 struct task_struct
*next
)
2532 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2533 struct perf_event_context
*next_ctx
;
2534 struct perf_event_context
*parent
, *next_parent
;
2535 struct perf_cpu_context
*cpuctx
;
2541 cpuctx
= __get_cpu_context(ctx
);
2542 if (!cpuctx
->task_ctx
)
2546 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2550 parent
= rcu_dereference(ctx
->parent_ctx
);
2551 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2553 /* If neither context have a parent context; they cannot be clones. */
2554 if (!parent
&& !next_parent
)
2557 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2559 * Looks like the two contexts are clones, so we might be
2560 * able to optimize the context switch. We lock both
2561 * contexts and check that they are clones under the
2562 * lock (including re-checking that neither has been
2563 * uncloned in the meantime). It doesn't matter which
2564 * order we take the locks because no other cpu could
2565 * be trying to lock both of these tasks.
2567 raw_spin_lock(&ctx
->lock
);
2568 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2569 if (context_equiv(ctx
, next_ctx
)) {
2571 * XXX do we need a memory barrier of sorts
2572 * wrt to rcu_dereference() of perf_event_ctxp
2574 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2575 next
->perf_event_ctxp
[ctxn
] = ctx
;
2577 next_ctx
->task
= task
;
2579 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2583 perf_event_sync_stat(ctx
, next_ctx
);
2585 raw_spin_unlock(&next_ctx
->lock
);
2586 raw_spin_unlock(&ctx
->lock
);
2592 raw_spin_lock(&ctx
->lock
);
2593 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2594 cpuctx
->task_ctx
= NULL
;
2595 raw_spin_unlock(&ctx
->lock
);
2599 void perf_sched_cb_dec(struct pmu
*pmu
)
2601 this_cpu_dec(perf_sched_cb_usages
);
2604 void perf_sched_cb_inc(struct pmu
*pmu
)
2606 this_cpu_inc(perf_sched_cb_usages
);
2610 * This function provides the context switch callback to the lower code
2611 * layer. It is invoked ONLY when the context switch callback is enabled.
2613 static void perf_pmu_sched_task(struct task_struct
*prev
,
2614 struct task_struct
*next
,
2617 struct perf_cpu_context
*cpuctx
;
2619 unsigned long flags
;
2624 local_irq_save(flags
);
2628 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2629 if (pmu
->sched_task
) {
2630 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2632 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2634 perf_pmu_disable(pmu
);
2636 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2638 perf_pmu_enable(pmu
);
2640 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2646 local_irq_restore(flags
);
2649 static void perf_event_switch(struct task_struct
*task
,
2650 struct task_struct
*next_prev
, bool sched_in
);
2652 #define for_each_task_context_nr(ctxn) \
2653 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2656 * Called from scheduler to remove the events of the current task,
2657 * with interrupts disabled.
2659 * We stop each event and update the event value in event->count.
2661 * This does not protect us against NMI, but disable()
2662 * sets the disabled bit in the control field of event _before_
2663 * accessing the event control register. If a NMI hits, then it will
2664 * not restart the event.
2666 void __perf_event_task_sched_out(struct task_struct
*task
,
2667 struct task_struct
*next
)
2671 if (__this_cpu_read(perf_sched_cb_usages
))
2672 perf_pmu_sched_task(task
, next
, false);
2674 if (atomic_read(&nr_switch_events
))
2675 perf_event_switch(task
, next
, false);
2677 for_each_task_context_nr(ctxn
)
2678 perf_event_context_sched_out(task
, ctxn
, next
);
2681 * if cgroup events exist on this CPU, then we need
2682 * to check if we have to switch out PMU state.
2683 * cgroup event are system-wide mode only
2685 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2686 perf_cgroup_sched_out(task
, next
);
2689 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2691 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2693 if (!cpuctx
->task_ctx
)
2696 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2699 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2700 cpuctx
->task_ctx
= NULL
;
2704 * Called with IRQs disabled
2706 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2707 enum event_type_t event_type
)
2709 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2713 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2714 struct perf_cpu_context
*cpuctx
)
2716 struct perf_event
*event
;
2718 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2719 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2721 if (!event_filter_match(event
))
2724 /* may need to reset tstamp_enabled */
2725 if (is_cgroup_event(event
))
2726 perf_cgroup_mark_enabled(event
, ctx
);
2728 if (group_can_go_on(event
, cpuctx
, 1))
2729 group_sched_in(event
, cpuctx
, ctx
);
2732 * If this pinned group hasn't been scheduled,
2733 * put it in error state.
2735 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2736 update_group_times(event
);
2737 event
->state
= PERF_EVENT_STATE_ERROR
;
2743 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2744 struct perf_cpu_context
*cpuctx
)
2746 struct perf_event
*event
;
2749 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2750 /* Ignore events in OFF or ERROR state */
2751 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2754 * Listen to the 'cpu' scheduling filter constraint
2757 if (!event_filter_match(event
))
2760 /* may need to reset tstamp_enabled */
2761 if (is_cgroup_event(event
))
2762 perf_cgroup_mark_enabled(event
, ctx
);
2764 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2765 if (group_sched_in(event
, cpuctx
, ctx
))
2772 ctx_sched_in(struct perf_event_context
*ctx
,
2773 struct perf_cpu_context
*cpuctx
,
2774 enum event_type_t event_type
,
2775 struct task_struct
*task
)
2778 int is_active
= ctx
->is_active
;
2780 ctx
->is_active
|= event_type
;
2781 if (likely(!ctx
->nr_events
))
2785 ctx
->timestamp
= now
;
2786 perf_cgroup_set_timestamp(task
, ctx
);
2788 * First go through the list and put on any pinned groups
2789 * in order to give them the best chance of going on.
2791 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2792 ctx_pinned_sched_in(ctx
, cpuctx
);
2794 /* Then walk through the lower prio flexible groups */
2795 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2796 ctx_flexible_sched_in(ctx
, cpuctx
);
2799 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2800 enum event_type_t event_type
,
2801 struct task_struct
*task
)
2803 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2805 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2808 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2809 struct task_struct
*task
)
2811 struct perf_cpu_context
*cpuctx
;
2813 cpuctx
= __get_cpu_context(ctx
);
2814 if (cpuctx
->task_ctx
== ctx
)
2817 perf_ctx_lock(cpuctx
, ctx
);
2818 perf_pmu_disable(ctx
->pmu
);
2820 * We want to keep the following priority order:
2821 * cpu pinned (that don't need to move), task pinned,
2822 * cpu flexible, task flexible.
2824 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2827 cpuctx
->task_ctx
= ctx
;
2829 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2831 perf_pmu_enable(ctx
->pmu
);
2832 perf_ctx_unlock(cpuctx
, ctx
);
2836 * Called from scheduler to add the events of the current task
2837 * with interrupts disabled.
2839 * We restore the event value and then enable it.
2841 * This does not protect us against NMI, but enable()
2842 * sets the enabled bit in the control field of event _before_
2843 * accessing the event control register. If a NMI hits, then it will
2844 * keep the event running.
2846 void __perf_event_task_sched_in(struct task_struct
*prev
,
2847 struct task_struct
*task
)
2849 struct perf_event_context
*ctx
;
2852 for_each_task_context_nr(ctxn
) {
2853 ctx
= task
->perf_event_ctxp
[ctxn
];
2857 perf_event_context_sched_in(ctx
, task
);
2860 * if cgroup events exist on this CPU, then we need
2861 * to check if we have to switch in PMU state.
2862 * cgroup event are system-wide mode only
2864 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2865 perf_cgroup_sched_in(prev
, task
);
2867 if (atomic_read(&nr_switch_events
))
2868 perf_event_switch(task
, prev
, true);
2870 if (__this_cpu_read(perf_sched_cb_usages
))
2871 perf_pmu_sched_task(prev
, task
, true);
2874 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2876 u64 frequency
= event
->attr
.sample_freq
;
2877 u64 sec
= NSEC_PER_SEC
;
2878 u64 divisor
, dividend
;
2880 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2882 count_fls
= fls64(count
);
2883 nsec_fls
= fls64(nsec
);
2884 frequency_fls
= fls64(frequency
);
2888 * We got @count in @nsec, with a target of sample_freq HZ
2889 * the target period becomes:
2892 * period = -------------------
2893 * @nsec * sample_freq
2898 * Reduce accuracy by one bit such that @a and @b converge
2899 * to a similar magnitude.
2901 #define REDUCE_FLS(a, b) \
2903 if (a##_fls > b##_fls) { \
2913 * Reduce accuracy until either term fits in a u64, then proceed with
2914 * the other, so that finally we can do a u64/u64 division.
2916 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2917 REDUCE_FLS(nsec
, frequency
);
2918 REDUCE_FLS(sec
, count
);
2921 if (count_fls
+ sec_fls
> 64) {
2922 divisor
= nsec
* frequency
;
2924 while (count_fls
+ sec_fls
> 64) {
2925 REDUCE_FLS(count
, sec
);
2929 dividend
= count
* sec
;
2931 dividend
= count
* sec
;
2933 while (nsec_fls
+ frequency_fls
> 64) {
2934 REDUCE_FLS(nsec
, frequency
);
2938 divisor
= nsec
* frequency
;
2944 return div64_u64(dividend
, divisor
);
2947 static DEFINE_PER_CPU(int, perf_throttled_count
);
2948 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2950 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2952 struct hw_perf_event
*hwc
= &event
->hw
;
2953 s64 period
, sample_period
;
2956 period
= perf_calculate_period(event
, nsec
, count
);
2958 delta
= (s64
)(period
- hwc
->sample_period
);
2959 delta
= (delta
+ 7) / 8; /* low pass filter */
2961 sample_period
= hwc
->sample_period
+ delta
;
2966 hwc
->sample_period
= sample_period
;
2968 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2970 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2972 local64_set(&hwc
->period_left
, 0);
2975 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2980 * combine freq adjustment with unthrottling to avoid two passes over the
2981 * events. At the same time, make sure, having freq events does not change
2982 * the rate of unthrottling as that would introduce bias.
2984 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2987 struct perf_event
*event
;
2988 struct hw_perf_event
*hwc
;
2989 u64 now
, period
= TICK_NSEC
;
2993 * only need to iterate over all events iff:
2994 * - context have events in frequency mode (needs freq adjust)
2995 * - there are events to unthrottle on this cpu
2997 if (!(ctx
->nr_freq
|| needs_unthr
))
3000 raw_spin_lock(&ctx
->lock
);
3001 perf_pmu_disable(ctx
->pmu
);
3003 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3004 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3007 if (!event_filter_match(event
))
3010 perf_pmu_disable(event
->pmu
);
3014 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3015 hwc
->interrupts
= 0;
3016 perf_log_throttle(event
, 1);
3017 event
->pmu
->start(event
, 0);
3020 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3024 * stop the event and update event->count
3026 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3028 now
= local64_read(&event
->count
);
3029 delta
= now
- hwc
->freq_count_stamp
;
3030 hwc
->freq_count_stamp
= now
;
3034 * reload only if value has changed
3035 * we have stopped the event so tell that
3036 * to perf_adjust_period() to avoid stopping it
3040 perf_adjust_period(event
, period
, delta
, false);
3042 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3044 perf_pmu_enable(event
->pmu
);
3047 perf_pmu_enable(ctx
->pmu
);
3048 raw_spin_unlock(&ctx
->lock
);
3052 * Round-robin a context's events:
3054 static void rotate_ctx(struct perf_event_context
*ctx
)
3057 * Rotate the first entry last of non-pinned groups. Rotation might be
3058 * disabled by the inheritance code.
3060 if (!ctx
->rotate_disable
)
3061 list_rotate_left(&ctx
->flexible_groups
);
3064 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3066 struct perf_event_context
*ctx
= NULL
;
3069 if (cpuctx
->ctx
.nr_events
) {
3070 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3074 ctx
= cpuctx
->task_ctx
;
3075 if (ctx
&& ctx
->nr_events
) {
3076 if (ctx
->nr_events
!= ctx
->nr_active
)
3083 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3084 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3086 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3088 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3090 rotate_ctx(&cpuctx
->ctx
);
3094 perf_event_sched_in(cpuctx
, ctx
, current
);
3096 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3097 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3103 #ifdef CONFIG_NO_HZ_FULL
3104 bool perf_event_can_stop_tick(void)
3106 if (atomic_read(&nr_freq_events
) ||
3107 __this_cpu_read(perf_throttled_count
))
3114 void perf_event_task_tick(void)
3116 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3117 struct perf_event_context
*ctx
, *tmp
;
3120 WARN_ON(!irqs_disabled());
3122 __this_cpu_inc(perf_throttled_seq
);
3123 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3125 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3126 perf_adjust_freq_unthr_context(ctx
, throttled
);
3129 static int event_enable_on_exec(struct perf_event
*event
,
3130 struct perf_event_context
*ctx
)
3132 if (!event
->attr
.enable_on_exec
)
3135 event
->attr
.enable_on_exec
= 0;
3136 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3139 __perf_event_mark_enabled(event
);
3145 * Enable all of a task's events that have been marked enable-on-exec.
3146 * This expects task == current.
3148 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
3150 struct perf_event_context
*clone_ctx
= NULL
;
3151 struct perf_event
*event
;
3152 unsigned long flags
;
3156 local_irq_save(flags
);
3157 if (!ctx
|| !ctx
->nr_events
)
3161 * We must ctxsw out cgroup events to avoid conflict
3162 * when invoking perf_task_event_sched_in() later on
3163 * in this function. Otherwise we end up trying to
3164 * ctxswin cgroup events which are already scheduled
3167 perf_cgroup_sched_out(current
, NULL
);
3169 raw_spin_lock(&ctx
->lock
);
3170 task_ctx_sched_out(ctx
);
3172 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3173 ret
= event_enable_on_exec(event
, ctx
);
3179 * Unclone this context if we enabled any event.
3182 clone_ctx
= unclone_ctx(ctx
);
3184 raw_spin_unlock(&ctx
->lock
);
3187 * Also calls ctxswin for cgroup events, if any:
3189 perf_event_context_sched_in(ctx
, ctx
->task
);
3191 local_irq_restore(flags
);
3197 void perf_event_exec(void)
3199 struct perf_event_context
*ctx
;
3203 for_each_task_context_nr(ctxn
) {
3204 ctx
= current
->perf_event_ctxp
[ctxn
];
3208 perf_event_enable_on_exec(ctx
);
3213 struct perf_read_data
{
3214 struct perf_event
*event
;
3220 * Cross CPU call to read the hardware event
3222 static void __perf_event_read(void *info
)
3224 struct perf_read_data
*data
= info
;
3225 struct perf_event
*sub
, *event
= data
->event
;
3226 struct perf_event_context
*ctx
= event
->ctx
;
3227 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3228 struct pmu
*pmu
= event
->pmu
;
3231 * If this is a task context, we need to check whether it is
3232 * the current task context of this cpu. If not it has been
3233 * scheduled out before the smp call arrived. In that case
3234 * event->count would have been updated to a recent sample
3235 * when the event was scheduled out.
3237 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3240 raw_spin_lock(&ctx
->lock
);
3241 if (ctx
->is_active
) {
3242 update_context_time(ctx
);
3243 update_cgrp_time_from_event(event
);
3246 update_event_times(event
);
3247 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3256 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3260 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3261 update_event_times(sub
);
3262 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3264 * Use sibling's PMU rather than @event's since
3265 * sibling could be on different (eg: software) PMU.
3267 sub
->pmu
->read(sub
);
3271 data
->ret
= pmu
->commit_txn(pmu
);
3274 raw_spin_unlock(&ctx
->lock
);
3277 static inline u64
perf_event_count(struct perf_event
*event
)
3279 if (event
->pmu
->count
)
3280 return event
->pmu
->count(event
);
3282 return __perf_event_count(event
);
3286 * NMI-safe method to read a local event, that is an event that
3288 * - either for the current task, or for this CPU
3289 * - does not have inherit set, for inherited task events
3290 * will not be local and we cannot read them atomically
3291 * - must not have a pmu::count method
3293 u64
perf_event_read_local(struct perf_event
*event
)
3295 unsigned long flags
;
3299 * Disabling interrupts avoids all counter scheduling (context
3300 * switches, timer based rotation and IPIs).
3302 local_irq_save(flags
);
3304 /* If this is a per-task event, it must be for current */
3305 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3306 event
->hw
.target
!= current
);
3308 /* If this is a per-CPU event, it must be for this CPU */
3309 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3310 event
->cpu
!= smp_processor_id());
3313 * It must not be an event with inherit set, we cannot read
3314 * all child counters from atomic context.
3316 WARN_ON_ONCE(event
->attr
.inherit
);
3319 * It must not have a pmu::count method, those are not
3322 WARN_ON_ONCE(event
->pmu
->count
);
3325 * If the event is currently on this CPU, its either a per-task event,
3326 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3329 if (event
->oncpu
== smp_processor_id())
3330 event
->pmu
->read(event
);
3332 val
= local64_read(&event
->count
);
3333 local_irq_restore(flags
);
3338 static int perf_event_read(struct perf_event
*event
, bool group
)
3343 * If event is enabled and currently active on a CPU, update the
3344 * value in the event structure:
3346 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3347 struct perf_read_data data
= {
3352 smp_call_function_single(event
->oncpu
,
3353 __perf_event_read
, &data
, 1);
3355 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3356 struct perf_event_context
*ctx
= event
->ctx
;
3357 unsigned long flags
;
3359 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3361 * may read while context is not active
3362 * (e.g., thread is blocked), in that case
3363 * we cannot update context time
3365 if (ctx
->is_active
) {
3366 update_context_time(ctx
);
3367 update_cgrp_time_from_event(event
);
3370 update_group_times(event
);
3372 update_event_times(event
);
3373 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3380 * Initialize the perf_event context in a task_struct:
3382 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3384 raw_spin_lock_init(&ctx
->lock
);
3385 mutex_init(&ctx
->mutex
);
3386 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3387 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3388 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3389 INIT_LIST_HEAD(&ctx
->event_list
);
3390 atomic_set(&ctx
->refcount
, 1);
3391 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3394 static struct perf_event_context
*
3395 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3397 struct perf_event_context
*ctx
;
3399 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3403 __perf_event_init_context(ctx
);
3406 get_task_struct(task
);
3413 static struct task_struct
*
3414 find_lively_task_by_vpid(pid_t vpid
)
3416 struct task_struct
*task
;
3423 task
= find_task_by_vpid(vpid
);
3425 get_task_struct(task
);
3429 return ERR_PTR(-ESRCH
);
3431 /* Reuse ptrace permission checks for now. */
3433 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3438 put_task_struct(task
);
3439 return ERR_PTR(err
);
3444 * Returns a matching context with refcount and pincount.
3446 static struct perf_event_context
*
3447 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3448 struct perf_event
*event
)
3450 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3451 struct perf_cpu_context
*cpuctx
;
3452 void *task_ctx_data
= NULL
;
3453 unsigned long flags
;
3455 int cpu
= event
->cpu
;
3458 /* Must be root to operate on a CPU event: */
3459 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3460 return ERR_PTR(-EACCES
);
3463 * We could be clever and allow to attach a event to an
3464 * offline CPU and activate it when the CPU comes up, but
3467 if (!cpu_online(cpu
))
3468 return ERR_PTR(-ENODEV
);
3470 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3479 ctxn
= pmu
->task_ctx_nr
;
3483 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3484 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3485 if (!task_ctx_data
) {
3492 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3494 clone_ctx
= unclone_ctx(ctx
);
3497 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3498 ctx
->task_ctx_data
= task_ctx_data
;
3499 task_ctx_data
= NULL
;
3501 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3506 ctx
= alloc_perf_context(pmu
, task
);
3511 if (task_ctx_data
) {
3512 ctx
->task_ctx_data
= task_ctx_data
;
3513 task_ctx_data
= NULL
;
3517 mutex_lock(&task
->perf_event_mutex
);
3519 * If it has already passed perf_event_exit_task().
3520 * we must see PF_EXITING, it takes this mutex too.
3522 if (task
->flags
& PF_EXITING
)
3524 else if (task
->perf_event_ctxp
[ctxn
])
3529 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3531 mutex_unlock(&task
->perf_event_mutex
);
3533 if (unlikely(err
)) {
3542 kfree(task_ctx_data
);
3546 kfree(task_ctx_data
);
3547 return ERR_PTR(err
);
3550 static void perf_event_free_filter(struct perf_event
*event
);
3551 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3553 static void free_event_rcu(struct rcu_head
*head
)
3555 struct perf_event
*event
;
3557 event
= container_of(head
, struct perf_event
, rcu_head
);
3559 put_pid_ns(event
->ns
);
3560 perf_event_free_filter(event
);
3564 static void ring_buffer_attach(struct perf_event
*event
,
3565 struct ring_buffer
*rb
);
3567 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3572 if (is_cgroup_event(event
))
3573 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3576 static void unaccount_event(struct perf_event
*event
)
3581 if (event
->attach_state
& PERF_ATTACH_TASK
)
3582 static_key_slow_dec_deferred(&perf_sched_events
);
3583 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3584 atomic_dec(&nr_mmap_events
);
3585 if (event
->attr
.comm
)
3586 atomic_dec(&nr_comm_events
);
3587 if (event
->attr
.task
)
3588 atomic_dec(&nr_task_events
);
3589 if (event
->attr
.freq
)
3590 atomic_dec(&nr_freq_events
);
3591 if (event
->attr
.context_switch
) {
3592 static_key_slow_dec_deferred(&perf_sched_events
);
3593 atomic_dec(&nr_switch_events
);
3595 if (is_cgroup_event(event
))
3596 static_key_slow_dec_deferred(&perf_sched_events
);
3597 if (has_branch_stack(event
))
3598 static_key_slow_dec_deferred(&perf_sched_events
);
3600 unaccount_event_cpu(event
, event
->cpu
);
3604 * The following implement mutual exclusion of events on "exclusive" pmus
3605 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3606 * at a time, so we disallow creating events that might conflict, namely:
3608 * 1) cpu-wide events in the presence of per-task events,
3609 * 2) per-task events in the presence of cpu-wide events,
3610 * 3) two matching events on the same context.
3612 * The former two cases are handled in the allocation path (perf_event_alloc(),
3613 * __free_event()), the latter -- before the first perf_install_in_context().
3615 static int exclusive_event_init(struct perf_event
*event
)
3617 struct pmu
*pmu
= event
->pmu
;
3619 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3623 * Prevent co-existence of per-task and cpu-wide events on the
3624 * same exclusive pmu.
3626 * Negative pmu::exclusive_cnt means there are cpu-wide
3627 * events on this "exclusive" pmu, positive means there are
3630 * Since this is called in perf_event_alloc() path, event::ctx
3631 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3632 * to mean "per-task event", because unlike other attach states it
3633 * never gets cleared.
3635 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3636 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3639 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3646 static void exclusive_event_destroy(struct perf_event
*event
)
3648 struct pmu
*pmu
= event
->pmu
;
3650 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3653 /* see comment in exclusive_event_init() */
3654 if (event
->attach_state
& PERF_ATTACH_TASK
)
3655 atomic_dec(&pmu
->exclusive_cnt
);
3657 atomic_inc(&pmu
->exclusive_cnt
);
3660 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3662 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3663 (e1
->cpu
== e2
->cpu
||
3670 /* Called under the same ctx::mutex as perf_install_in_context() */
3671 static bool exclusive_event_installable(struct perf_event
*event
,
3672 struct perf_event_context
*ctx
)
3674 struct perf_event
*iter_event
;
3675 struct pmu
*pmu
= event
->pmu
;
3677 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3680 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3681 if (exclusive_event_match(iter_event
, event
))
3688 static void __free_event(struct perf_event
*event
)
3690 if (!event
->parent
) {
3691 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3692 put_callchain_buffers();
3695 perf_event_free_bpf_prog(event
);
3698 event
->destroy(event
);
3701 put_ctx(event
->ctx
);
3704 exclusive_event_destroy(event
);
3705 module_put(event
->pmu
->module
);
3708 call_rcu(&event
->rcu_head
, free_event_rcu
);
3711 static void _free_event(struct perf_event
*event
)
3713 irq_work_sync(&event
->pending
);
3715 unaccount_event(event
);
3719 * Can happen when we close an event with re-directed output.
3721 * Since we have a 0 refcount, perf_mmap_close() will skip
3722 * over us; possibly making our ring_buffer_put() the last.
3724 mutex_lock(&event
->mmap_mutex
);
3725 ring_buffer_attach(event
, NULL
);
3726 mutex_unlock(&event
->mmap_mutex
);
3729 if (is_cgroup_event(event
))
3730 perf_detach_cgroup(event
);
3732 __free_event(event
);
3736 * Used to free events which have a known refcount of 1, such as in error paths
3737 * where the event isn't exposed yet and inherited events.
3739 static void free_event(struct perf_event
*event
)
3741 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3742 "unexpected event refcount: %ld; ptr=%p\n",
3743 atomic_long_read(&event
->refcount
), event
)) {
3744 /* leak to avoid use-after-free */
3752 * Remove user event from the owner task.
3754 static void perf_remove_from_owner(struct perf_event
*event
)
3756 struct task_struct
*owner
;
3759 owner
= ACCESS_ONCE(event
->owner
);
3761 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3762 * !owner it means the list deletion is complete and we can indeed
3763 * free this event, otherwise we need to serialize on
3764 * owner->perf_event_mutex.
3766 smp_read_barrier_depends();
3769 * Since delayed_put_task_struct() also drops the last
3770 * task reference we can safely take a new reference
3771 * while holding the rcu_read_lock().
3773 get_task_struct(owner
);
3779 * If we're here through perf_event_exit_task() we're already
3780 * holding ctx->mutex which would be an inversion wrt. the
3781 * normal lock order.
3783 * However we can safely take this lock because its the child
3786 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3789 * We have to re-check the event->owner field, if it is cleared
3790 * we raced with perf_event_exit_task(), acquiring the mutex
3791 * ensured they're done, and we can proceed with freeing the
3795 list_del_init(&event
->owner_entry
);
3796 mutex_unlock(&owner
->perf_event_mutex
);
3797 put_task_struct(owner
);
3801 static void put_event(struct perf_event
*event
)
3803 struct perf_event_context
*ctx
;
3805 if (!atomic_long_dec_and_test(&event
->refcount
))
3808 if (!is_kernel_event(event
))
3809 perf_remove_from_owner(event
);
3812 * There are two ways this annotation is useful:
3814 * 1) there is a lock recursion from perf_event_exit_task
3815 * see the comment there.
3817 * 2) there is a lock-inversion with mmap_sem through
3818 * perf_read_group(), which takes faults while
3819 * holding ctx->mutex, however this is called after
3820 * the last filedesc died, so there is no possibility
3821 * to trigger the AB-BA case.
3823 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3824 WARN_ON_ONCE(ctx
->parent_ctx
);
3825 perf_remove_from_context(event
, true);
3826 perf_event_ctx_unlock(event
, ctx
);
3831 int perf_event_release_kernel(struct perf_event
*event
)
3836 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3839 * Called when the last reference to the file is gone.
3841 static int perf_release(struct inode
*inode
, struct file
*file
)
3843 put_event(file
->private_data
);
3848 * Remove all orphanes events from the context.
3850 static void orphans_remove_work(struct work_struct
*work
)
3852 struct perf_event_context
*ctx
;
3853 struct perf_event
*event
, *tmp
;
3855 ctx
= container_of(work
, struct perf_event_context
,
3856 orphans_remove
.work
);
3858 mutex_lock(&ctx
->mutex
);
3859 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3860 struct perf_event
*parent_event
= event
->parent
;
3862 if (!is_orphaned_child(event
))
3865 perf_remove_from_context(event
, true);
3867 mutex_lock(&parent_event
->child_mutex
);
3868 list_del_init(&event
->child_list
);
3869 mutex_unlock(&parent_event
->child_mutex
);
3872 put_event(parent_event
);
3875 raw_spin_lock_irq(&ctx
->lock
);
3876 ctx
->orphans_remove_sched
= false;
3877 raw_spin_unlock_irq(&ctx
->lock
);
3878 mutex_unlock(&ctx
->mutex
);
3883 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3885 struct perf_event
*child
;
3891 mutex_lock(&event
->child_mutex
);
3893 (void)perf_event_read(event
, false);
3894 total
+= perf_event_count(event
);
3896 *enabled
+= event
->total_time_enabled
+
3897 atomic64_read(&event
->child_total_time_enabled
);
3898 *running
+= event
->total_time_running
+
3899 atomic64_read(&event
->child_total_time_running
);
3901 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3902 (void)perf_event_read(child
, false);
3903 total
+= perf_event_count(child
);
3904 *enabled
+= child
->total_time_enabled
;
3905 *running
+= child
->total_time_running
;
3907 mutex_unlock(&event
->child_mutex
);
3911 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3913 static int __perf_read_group_add(struct perf_event
*leader
,
3914 u64 read_format
, u64
*values
)
3916 struct perf_event
*sub
;
3917 int n
= 1; /* skip @nr */
3920 ret
= perf_event_read(leader
, true);
3925 * Since we co-schedule groups, {enabled,running} times of siblings
3926 * will be identical to those of the leader, so we only publish one
3929 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3930 values
[n
++] += leader
->total_time_enabled
+
3931 atomic64_read(&leader
->child_total_time_enabled
);
3934 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3935 values
[n
++] += leader
->total_time_running
+
3936 atomic64_read(&leader
->child_total_time_running
);
3940 * Write {count,id} tuples for every sibling.
3942 values
[n
++] += perf_event_count(leader
);
3943 if (read_format
& PERF_FORMAT_ID
)
3944 values
[n
++] = primary_event_id(leader
);
3946 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3947 values
[n
++] += perf_event_count(sub
);
3948 if (read_format
& PERF_FORMAT_ID
)
3949 values
[n
++] = primary_event_id(sub
);
3955 static int perf_read_group(struct perf_event
*event
,
3956 u64 read_format
, char __user
*buf
)
3958 struct perf_event
*leader
= event
->group_leader
, *child
;
3959 struct perf_event_context
*ctx
= leader
->ctx
;
3963 lockdep_assert_held(&ctx
->mutex
);
3965 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3969 values
[0] = 1 + leader
->nr_siblings
;
3972 * By locking the child_mutex of the leader we effectively
3973 * lock the child list of all siblings.. XXX explain how.
3975 mutex_lock(&leader
->child_mutex
);
3977 ret
= __perf_read_group_add(leader
, read_format
, values
);
3981 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3982 ret
= __perf_read_group_add(child
, read_format
, values
);
3987 mutex_unlock(&leader
->child_mutex
);
3989 ret
= event
->read_size
;
3990 if (copy_to_user(buf
, values
, event
->read_size
))
3995 mutex_unlock(&leader
->child_mutex
);
4001 static int perf_read_one(struct perf_event
*event
,
4002 u64 read_format
, char __user
*buf
)
4004 u64 enabled
, running
;
4008 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4009 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4010 values
[n
++] = enabled
;
4011 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4012 values
[n
++] = running
;
4013 if (read_format
& PERF_FORMAT_ID
)
4014 values
[n
++] = primary_event_id(event
);
4016 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4019 return n
* sizeof(u64
);
4022 static bool is_event_hup(struct perf_event
*event
)
4026 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
4029 mutex_lock(&event
->child_mutex
);
4030 no_children
= list_empty(&event
->child_list
);
4031 mutex_unlock(&event
->child_mutex
);
4036 * Read the performance event - simple non blocking version for now
4039 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4041 u64 read_format
= event
->attr
.read_format
;
4045 * Return end-of-file for a read on a event that is in
4046 * error state (i.e. because it was pinned but it couldn't be
4047 * scheduled on to the CPU at some point).
4049 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4052 if (count
< event
->read_size
)
4055 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4056 if (read_format
& PERF_FORMAT_GROUP
)
4057 ret
= perf_read_group(event
, read_format
, buf
);
4059 ret
= perf_read_one(event
, read_format
, buf
);
4065 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4067 struct perf_event
*event
= file
->private_data
;
4068 struct perf_event_context
*ctx
;
4071 ctx
= perf_event_ctx_lock(event
);
4072 ret
= __perf_read(event
, buf
, count
);
4073 perf_event_ctx_unlock(event
, ctx
);
4078 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4080 struct perf_event
*event
= file
->private_data
;
4081 struct ring_buffer
*rb
;
4082 unsigned int events
= POLLHUP
;
4084 poll_wait(file
, &event
->waitq
, wait
);
4086 if (is_event_hup(event
))
4090 * Pin the event->rb by taking event->mmap_mutex; otherwise
4091 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4093 mutex_lock(&event
->mmap_mutex
);
4096 events
= atomic_xchg(&rb
->poll
, 0);
4097 mutex_unlock(&event
->mmap_mutex
);
4101 static void _perf_event_reset(struct perf_event
*event
)
4103 (void)perf_event_read(event
, false);
4104 local64_set(&event
->count
, 0);
4105 perf_event_update_userpage(event
);
4109 * Holding the top-level event's child_mutex means that any
4110 * descendant process that has inherited this event will block
4111 * in sync_child_event if it goes to exit, thus satisfying the
4112 * task existence requirements of perf_event_enable/disable.
4114 static void perf_event_for_each_child(struct perf_event
*event
,
4115 void (*func
)(struct perf_event
*))
4117 struct perf_event
*child
;
4119 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4121 mutex_lock(&event
->child_mutex
);
4123 list_for_each_entry(child
, &event
->child_list
, child_list
)
4125 mutex_unlock(&event
->child_mutex
);
4128 static void perf_event_for_each(struct perf_event
*event
,
4129 void (*func
)(struct perf_event
*))
4131 struct perf_event_context
*ctx
= event
->ctx
;
4132 struct perf_event
*sibling
;
4134 lockdep_assert_held(&ctx
->mutex
);
4136 event
= event
->group_leader
;
4138 perf_event_for_each_child(event
, func
);
4139 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4140 perf_event_for_each_child(sibling
, func
);
4143 struct period_event
{
4144 struct perf_event
*event
;
4148 static int __perf_event_period(void *info
)
4150 struct period_event
*pe
= info
;
4151 struct perf_event
*event
= pe
->event
;
4152 struct perf_event_context
*ctx
= event
->ctx
;
4153 u64 value
= pe
->value
;
4156 raw_spin_lock(&ctx
->lock
);
4157 if (event
->attr
.freq
) {
4158 event
->attr
.sample_freq
= value
;
4160 event
->attr
.sample_period
= value
;
4161 event
->hw
.sample_period
= value
;
4164 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4166 perf_pmu_disable(ctx
->pmu
);
4167 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4170 local64_set(&event
->hw
.period_left
, 0);
4173 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4174 perf_pmu_enable(ctx
->pmu
);
4176 raw_spin_unlock(&ctx
->lock
);
4181 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4183 struct period_event pe
= { .event
= event
, };
4184 struct perf_event_context
*ctx
= event
->ctx
;
4185 struct task_struct
*task
;
4188 if (!is_sampling_event(event
))
4191 if (copy_from_user(&value
, arg
, sizeof(value
)))
4197 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4204 cpu_function_call(event
->cpu
, __perf_event_period
, &pe
);
4209 if (!task_function_call(task
, __perf_event_period
, &pe
))
4212 raw_spin_lock_irq(&ctx
->lock
);
4213 if (ctx
->is_active
) {
4214 raw_spin_unlock_irq(&ctx
->lock
);
4219 __perf_event_period(&pe
);
4220 raw_spin_unlock_irq(&ctx
->lock
);
4225 static const struct file_operations perf_fops
;
4227 static inline int perf_fget_light(int fd
, struct fd
*p
)
4229 struct fd f
= fdget(fd
);
4233 if (f
.file
->f_op
!= &perf_fops
) {
4241 static int perf_event_set_output(struct perf_event
*event
,
4242 struct perf_event
*output_event
);
4243 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4244 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4246 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4248 void (*func
)(struct perf_event
*);
4252 case PERF_EVENT_IOC_ENABLE
:
4253 func
= _perf_event_enable
;
4255 case PERF_EVENT_IOC_DISABLE
:
4256 func
= _perf_event_disable
;
4258 case PERF_EVENT_IOC_RESET
:
4259 func
= _perf_event_reset
;
4262 case PERF_EVENT_IOC_REFRESH
:
4263 return _perf_event_refresh(event
, arg
);
4265 case PERF_EVENT_IOC_PERIOD
:
4266 return perf_event_period(event
, (u64 __user
*)arg
);
4268 case PERF_EVENT_IOC_ID
:
4270 u64 id
= primary_event_id(event
);
4272 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4277 case PERF_EVENT_IOC_SET_OUTPUT
:
4281 struct perf_event
*output_event
;
4283 ret
= perf_fget_light(arg
, &output
);
4286 output_event
= output
.file
->private_data
;
4287 ret
= perf_event_set_output(event
, output_event
);
4290 ret
= perf_event_set_output(event
, NULL
);
4295 case PERF_EVENT_IOC_SET_FILTER
:
4296 return perf_event_set_filter(event
, (void __user
*)arg
);
4298 case PERF_EVENT_IOC_SET_BPF
:
4299 return perf_event_set_bpf_prog(event
, arg
);
4305 if (flags
& PERF_IOC_FLAG_GROUP
)
4306 perf_event_for_each(event
, func
);
4308 perf_event_for_each_child(event
, func
);
4313 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4315 struct perf_event
*event
= file
->private_data
;
4316 struct perf_event_context
*ctx
;
4319 ctx
= perf_event_ctx_lock(event
);
4320 ret
= _perf_ioctl(event
, cmd
, arg
);
4321 perf_event_ctx_unlock(event
, ctx
);
4326 #ifdef CONFIG_COMPAT
4327 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4330 switch (_IOC_NR(cmd
)) {
4331 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4332 case _IOC_NR(PERF_EVENT_IOC_ID
):
4333 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4334 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4335 cmd
&= ~IOCSIZE_MASK
;
4336 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4340 return perf_ioctl(file
, cmd
, arg
);
4343 # define perf_compat_ioctl NULL
4346 int perf_event_task_enable(void)
4348 struct perf_event_context
*ctx
;
4349 struct perf_event
*event
;
4351 mutex_lock(¤t
->perf_event_mutex
);
4352 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4353 ctx
= perf_event_ctx_lock(event
);
4354 perf_event_for_each_child(event
, _perf_event_enable
);
4355 perf_event_ctx_unlock(event
, ctx
);
4357 mutex_unlock(¤t
->perf_event_mutex
);
4362 int perf_event_task_disable(void)
4364 struct perf_event_context
*ctx
;
4365 struct perf_event
*event
;
4367 mutex_lock(¤t
->perf_event_mutex
);
4368 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4369 ctx
= perf_event_ctx_lock(event
);
4370 perf_event_for_each_child(event
, _perf_event_disable
);
4371 perf_event_ctx_unlock(event
, ctx
);
4373 mutex_unlock(¤t
->perf_event_mutex
);
4378 static int perf_event_index(struct perf_event
*event
)
4380 if (event
->hw
.state
& PERF_HES_STOPPED
)
4383 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4386 return event
->pmu
->event_idx(event
);
4389 static void calc_timer_values(struct perf_event
*event
,
4396 *now
= perf_clock();
4397 ctx_time
= event
->shadow_ctx_time
+ *now
;
4398 *enabled
= ctx_time
- event
->tstamp_enabled
;
4399 *running
= ctx_time
- event
->tstamp_running
;
4402 static void perf_event_init_userpage(struct perf_event
*event
)
4404 struct perf_event_mmap_page
*userpg
;
4405 struct ring_buffer
*rb
;
4408 rb
= rcu_dereference(event
->rb
);
4412 userpg
= rb
->user_page
;
4414 /* Allow new userspace to detect that bit 0 is deprecated */
4415 userpg
->cap_bit0_is_deprecated
= 1;
4416 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4417 userpg
->data_offset
= PAGE_SIZE
;
4418 userpg
->data_size
= perf_data_size(rb
);
4424 void __weak
arch_perf_update_userpage(
4425 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4430 * Callers need to ensure there can be no nesting of this function, otherwise
4431 * the seqlock logic goes bad. We can not serialize this because the arch
4432 * code calls this from NMI context.
4434 void perf_event_update_userpage(struct perf_event
*event
)
4436 struct perf_event_mmap_page
*userpg
;
4437 struct ring_buffer
*rb
;
4438 u64 enabled
, running
, now
;
4441 rb
= rcu_dereference(event
->rb
);
4446 * compute total_time_enabled, total_time_running
4447 * based on snapshot values taken when the event
4448 * was last scheduled in.
4450 * we cannot simply called update_context_time()
4451 * because of locking issue as we can be called in
4454 calc_timer_values(event
, &now
, &enabled
, &running
);
4456 userpg
= rb
->user_page
;
4458 * Disable preemption so as to not let the corresponding user-space
4459 * spin too long if we get preempted.
4464 userpg
->index
= perf_event_index(event
);
4465 userpg
->offset
= perf_event_count(event
);
4467 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4469 userpg
->time_enabled
= enabled
+
4470 atomic64_read(&event
->child_total_time_enabled
);
4472 userpg
->time_running
= running
+
4473 atomic64_read(&event
->child_total_time_running
);
4475 arch_perf_update_userpage(event
, userpg
, now
);
4484 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4486 struct perf_event
*event
= vma
->vm_file
->private_data
;
4487 struct ring_buffer
*rb
;
4488 int ret
= VM_FAULT_SIGBUS
;
4490 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4491 if (vmf
->pgoff
== 0)
4497 rb
= rcu_dereference(event
->rb
);
4501 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4504 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4508 get_page(vmf
->page
);
4509 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4510 vmf
->page
->index
= vmf
->pgoff
;
4519 static void ring_buffer_attach(struct perf_event
*event
,
4520 struct ring_buffer
*rb
)
4522 struct ring_buffer
*old_rb
= NULL
;
4523 unsigned long flags
;
4527 * Should be impossible, we set this when removing
4528 * event->rb_entry and wait/clear when adding event->rb_entry.
4530 WARN_ON_ONCE(event
->rcu_pending
);
4533 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4534 list_del_rcu(&event
->rb_entry
);
4535 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4537 event
->rcu_batches
= get_state_synchronize_rcu();
4538 event
->rcu_pending
= 1;
4542 if (event
->rcu_pending
) {
4543 cond_synchronize_rcu(event
->rcu_batches
);
4544 event
->rcu_pending
= 0;
4547 spin_lock_irqsave(&rb
->event_lock
, flags
);
4548 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4549 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4552 rcu_assign_pointer(event
->rb
, rb
);
4555 ring_buffer_put(old_rb
);
4557 * Since we detached before setting the new rb, so that we
4558 * could attach the new rb, we could have missed a wakeup.
4561 wake_up_all(&event
->waitq
);
4565 static void ring_buffer_wakeup(struct perf_event
*event
)
4567 struct ring_buffer
*rb
;
4570 rb
= rcu_dereference(event
->rb
);
4572 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4573 wake_up_all(&event
->waitq
);
4578 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4580 struct ring_buffer
*rb
;
4583 rb
= rcu_dereference(event
->rb
);
4585 if (!atomic_inc_not_zero(&rb
->refcount
))
4593 void ring_buffer_put(struct ring_buffer
*rb
)
4595 if (!atomic_dec_and_test(&rb
->refcount
))
4598 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4600 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4603 static void perf_mmap_open(struct vm_area_struct
*vma
)
4605 struct perf_event
*event
= vma
->vm_file
->private_data
;
4607 atomic_inc(&event
->mmap_count
);
4608 atomic_inc(&event
->rb
->mmap_count
);
4611 atomic_inc(&event
->rb
->aux_mmap_count
);
4613 if (event
->pmu
->event_mapped
)
4614 event
->pmu
->event_mapped(event
);
4618 * A buffer can be mmap()ed multiple times; either directly through the same
4619 * event, or through other events by use of perf_event_set_output().
4621 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4622 * the buffer here, where we still have a VM context. This means we need
4623 * to detach all events redirecting to us.
4625 static void perf_mmap_close(struct vm_area_struct
*vma
)
4627 struct perf_event
*event
= vma
->vm_file
->private_data
;
4629 struct ring_buffer
*rb
= ring_buffer_get(event
);
4630 struct user_struct
*mmap_user
= rb
->mmap_user
;
4631 int mmap_locked
= rb
->mmap_locked
;
4632 unsigned long size
= perf_data_size(rb
);
4634 if (event
->pmu
->event_unmapped
)
4635 event
->pmu
->event_unmapped(event
);
4638 * rb->aux_mmap_count will always drop before rb->mmap_count and
4639 * event->mmap_count, so it is ok to use event->mmap_mutex to
4640 * serialize with perf_mmap here.
4642 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4643 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4644 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4645 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4648 mutex_unlock(&event
->mmap_mutex
);
4651 atomic_dec(&rb
->mmap_count
);
4653 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4656 ring_buffer_attach(event
, NULL
);
4657 mutex_unlock(&event
->mmap_mutex
);
4659 /* If there's still other mmap()s of this buffer, we're done. */
4660 if (atomic_read(&rb
->mmap_count
))
4664 * No other mmap()s, detach from all other events that might redirect
4665 * into the now unreachable buffer. Somewhat complicated by the
4666 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4670 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4671 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4673 * This event is en-route to free_event() which will
4674 * detach it and remove it from the list.
4680 mutex_lock(&event
->mmap_mutex
);
4682 * Check we didn't race with perf_event_set_output() which can
4683 * swizzle the rb from under us while we were waiting to
4684 * acquire mmap_mutex.
4686 * If we find a different rb; ignore this event, a next
4687 * iteration will no longer find it on the list. We have to
4688 * still restart the iteration to make sure we're not now
4689 * iterating the wrong list.
4691 if (event
->rb
== rb
)
4692 ring_buffer_attach(event
, NULL
);
4694 mutex_unlock(&event
->mmap_mutex
);
4698 * Restart the iteration; either we're on the wrong list or
4699 * destroyed its integrity by doing a deletion.
4706 * It could be there's still a few 0-ref events on the list; they'll
4707 * get cleaned up by free_event() -- they'll also still have their
4708 * ref on the rb and will free it whenever they are done with it.
4710 * Aside from that, this buffer is 'fully' detached and unmapped,
4711 * undo the VM accounting.
4714 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4715 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4716 free_uid(mmap_user
);
4719 ring_buffer_put(rb
); /* could be last */
4722 static const struct vm_operations_struct perf_mmap_vmops
= {
4723 .open
= perf_mmap_open
,
4724 .close
= perf_mmap_close
, /* non mergable */
4725 .fault
= perf_mmap_fault
,
4726 .page_mkwrite
= perf_mmap_fault
,
4729 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4731 struct perf_event
*event
= file
->private_data
;
4732 unsigned long user_locked
, user_lock_limit
;
4733 struct user_struct
*user
= current_user();
4734 unsigned long locked
, lock_limit
;
4735 struct ring_buffer
*rb
= NULL
;
4736 unsigned long vma_size
;
4737 unsigned long nr_pages
;
4738 long user_extra
= 0, extra
= 0;
4739 int ret
= 0, flags
= 0;
4742 * Don't allow mmap() of inherited per-task counters. This would
4743 * create a performance issue due to all children writing to the
4746 if (event
->cpu
== -1 && event
->attr
.inherit
)
4749 if (!(vma
->vm_flags
& VM_SHARED
))
4752 vma_size
= vma
->vm_end
- vma
->vm_start
;
4754 if (vma
->vm_pgoff
== 0) {
4755 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4758 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4759 * mapped, all subsequent mappings should have the same size
4760 * and offset. Must be above the normal perf buffer.
4762 u64 aux_offset
, aux_size
;
4767 nr_pages
= vma_size
/ PAGE_SIZE
;
4769 mutex_lock(&event
->mmap_mutex
);
4776 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4777 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4779 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4782 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4785 /* already mapped with a different offset */
4786 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4789 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4792 /* already mapped with a different size */
4793 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4796 if (!is_power_of_2(nr_pages
))
4799 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4802 if (rb_has_aux(rb
)) {
4803 atomic_inc(&rb
->aux_mmap_count
);
4808 atomic_set(&rb
->aux_mmap_count
, 1);
4809 user_extra
= nr_pages
;
4815 * If we have rb pages ensure they're a power-of-two number, so we
4816 * can do bitmasks instead of modulo.
4818 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4821 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4824 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4826 mutex_lock(&event
->mmap_mutex
);
4828 if (event
->rb
->nr_pages
!= nr_pages
) {
4833 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4835 * Raced against perf_mmap_close() through
4836 * perf_event_set_output(). Try again, hope for better
4839 mutex_unlock(&event
->mmap_mutex
);
4846 user_extra
= nr_pages
+ 1;
4849 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4852 * Increase the limit linearly with more CPUs:
4854 user_lock_limit
*= num_online_cpus();
4856 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4858 if (user_locked
> user_lock_limit
)
4859 extra
= user_locked
- user_lock_limit
;
4861 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4862 lock_limit
>>= PAGE_SHIFT
;
4863 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4865 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4866 !capable(CAP_IPC_LOCK
)) {
4871 WARN_ON(!rb
&& event
->rb
);
4873 if (vma
->vm_flags
& VM_WRITE
)
4874 flags
|= RING_BUFFER_WRITABLE
;
4877 rb
= rb_alloc(nr_pages
,
4878 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4886 atomic_set(&rb
->mmap_count
, 1);
4887 rb
->mmap_user
= get_current_user();
4888 rb
->mmap_locked
= extra
;
4890 ring_buffer_attach(event
, rb
);
4892 perf_event_init_userpage(event
);
4893 perf_event_update_userpage(event
);
4895 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4896 event
->attr
.aux_watermark
, flags
);
4898 rb
->aux_mmap_locked
= extra
;
4903 atomic_long_add(user_extra
, &user
->locked_vm
);
4904 vma
->vm_mm
->pinned_vm
+= extra
;
4906 atomic_inc(&event
->mmap_count
);
4908 atomic_dec(&rb
->mmap_count
);
4911 mutex_unlock(&event
->mmap_mutex
);
4914 * Since pinned accounting is per vm we cannot allow fork() to copy our
4917 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4918 vma
->vm_ops
= &perf_mmap_vmops
;
4920 if (event
->pmu
->event_mapped
)
4921 event
->pmu
->event_mapped(event
);
4926 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4928 struct inode
*inode
= file_inode(filp
);
4929 struct perf_event
*event
= filp
->private_data
;
4932 mutex_lock(&inode
->i_mutex
);
4933 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4934 mutex_unlock(&inode
->i_mutex
);
4942 static const struct file_operations perf_fops
= {
4943 .llseek
= no_llseek
,
4944 .release
= perf_release
,
4947 .unlocked_ioctl
= perf_ioctl
,
4948 .compat_ioctl
= perf_compat_ioctl
,
4950 .fasync
= perf_fasync
,
4956 * If there's data, ensure we set the poll() state and publish everything
4957 * to user-space before waking everybody up.
4960 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4962 /* only the parent has fasync state */
4964 event
= event
->parent
;
4965 return &event
->fasync
;
4968 void perf_event_wakeup(struct perf_event
*event
)
4970 ring_buffer_wakeup(event
);
4972 if (event
->pending_kill
) {
4973 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4974 event
->pending_kill
= 0;
4978 static void perf_pending_event(struct irq_work
*entry
)
4980 struct perf_event
*event
= container_of(entry
,
4981 struct perf_event
, pending
);
4984 rctx
= perf_swevent_get_recursion_context();
4986 * If we 'fail' here, that's OK, it means recursion is already disabled
4987 * and we won't recurse 'further'.
4990 if (event
->pending_disable
) {
4991 event
->pending_disable
= 0;
4992 __perf_event_disable(event
);
4995 if (event
->pending_wakeup
) {
4996 event
->pending_wakeup
= 0;
4997 perf_event_wakeup(event
);
5001 perf_swevent_put_recursion_context(rctx
);
5005 * We assume there is only KVM supporting the callbacks.
5006 * Later on, we might change it to a list if there is
5007 * another virtualization implementation supporting the callbacks.
5009 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5011 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5013 perf_guest_cbs
= cbs
;
5016 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5018 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5020 perf_guest_cbs
= NULL
;
5023 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5026 perf_output_sample_regs(struct perf_output_handle
*handle
,
5027 struct pt_regs
*regs
, u64 mask
)
5031 for_each_set_bit(bit
, (const unsigned long *) &mask
,
5032 sizeof(mask
) * BITS_PER_BYTE
) {
5035 val
= perf_reg_value(regs
, bit
);
5036 perf_output_put(handle
, val
);
5040 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5041 struct pt_regs
*regs
,
5042 struct pt_regs
*regs_user_copy
)
5044 if (user_mode(regs
)) {
5045 regs_user
->abi
= perf_reg_abi(current
);
5046 regs_user
->regs
= regs
;
5047 } else if (current
->mm
) {
5048 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5050 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5051 regs_user
->regs
= NULL
;
5055 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5056 struct pt_regs
*regs
)
5058 regs_intr
->regs
= regs
;
5059 regs_intr
->abi
= perf_reg_abi(current
);
5064 * Get remaining task size from user stack pointer.
5066 * It'd be better to take stack vma map and limit this more
5067 * precisly, but there's no way to get it safely under interrupt,
5068 * so using TASK_SIZE as limit.
5070 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5072 unsigned long addr
= perf_user_stack_pointer(regs
);
5074 if (!addr
|| addr
>= TASK_SIZE
)
5077 return TASK_SIZE
- addr
;
5081 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5082 struct pt_regs
*regs
)
5086 /* No regs, no stack pointer, no dump. */
5091 * Check if we fit in with the requested stack size into the:
5093 * If we don't, we limit the size to the TASK_SIZE.
5095 * - remaining sample size
5096 * If we don't, we customize the stack size to
5097 * fit in to the remaining sample size.
5100 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5101 stack_size
= min(stack_size
, (u16
) task_size
);
5103 /* Current header size plus static size and dynamic size. */
5104 header_size
+= 2 * sizeof(u64
);
5106 /* Do we fit in with the current stack dump size? */
5107 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5109 * If we overflow the maximum size for the sample,
5110 * we customize the stack dump size to fit in.
5112 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5113 stack_size
= round_up(stack_size
, sizeof(u64
));
5120 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5121 struct pt_regs
*regs
)
5123 /* Case of a kernel thread, nothing to dump */
5126 perf_output_put(handle
, size
);
5135 * - the size requested by user or the best one we can fit
5136 * in to the sample max size
5138 * - user stack dump data
5140 * - the actual dumped size
5144 perf_output_put(handle
, dump_size
);
5147 sp
= perf_user_stack_pointer(regs
);
5148 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5149 dyn_size
= dump_size
- rem
;
5151 perf_output_skip(handle
, rem
);
5154 perf_output_put(handle
, dyn_size
);
5158 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5159 struct perf_sample_data
*data
,
5160 struct perf_event
*event
)
5162 u64 sample_type
= event
->attr
.sample_type
;
5164 data
->type
= sample_type
;
5165 header
->size
+= event
->id_header_size
;
5167 if (sample_type
& PERF_SAMPLE_TID
) {
5168 /* namespace issues */
5169 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5170 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5173 if (sample_type
& PERF_SAMPLE_TIME
)
5174 data
->time
= perf_event_clock(event
);
5176 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5177 data
->id
= primary_event_id(event
);
5179 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5180 data
->stream_id
= event
->id
;
5182 if (sample_type
& PERF_SAMPLE_CPU
) {
5183 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5184 data
->cpu_entry
.reserved
= 0;
5188 void perf_event_header__init_id(struct perf_event_header
*header
,
5189 struct perf_sample_data
*data
,
5190 struct perf_event
*event
)
5192 if (event
->attr
.sample_id_all
)
5193 __perf_event_header__init_id(header
, data
, event
);
5196 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5197 struct perf_sample_data
*data
)
5199 u64 sample_type
= data
->type
;
5201 if (sample_type
& PERF_SAMPLE_TID
)
5202 perf_output_put(handle
, data
->tid_entry
);
5204 if (sample_type
& PERF_SAMPLE_TIME
)
5205 perf_output_put(handle
, data
->time
);
5207 if (sample_type
& PERF_SAMPLE_ID
)
5208 perf_output_put(handle
, data
->id
);
5210 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5211 perf_output_put(handle
, data
->stream_id
);
5213 if (sample_type
& PERF_SAMPLE_CPU
)
5214 perf_output_put(handle
, data
->cpu_entry
);
5216 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5217 perf_output_put(handle
, data
->id
);
5220 void perf_event__output_id_sample(struct perf_event
*event
,
5221 struct perf_output_handle
*handle
,
5222 struct perf_sample_data
*sample
)
5224 if (event
->attr
.sample_id_all
)
5225 __perf_event__output_id_sample(handle
, sample
);
5228 static void perf_output_read_one(struct perf_output_handle
*handle
,
5229 struct perf_event
*event
,
5230 u64 enabled
, u64 running
)
5232 u64 read_format
= event
->attr
.read_format
;
5236 values
[n
++] = perf_event_count(event
);
5237 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5238 values
[n
++] = enabled
+
5239 atomic64_read(&event
->child_total_time_enabled
);
5241 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5242 values
[n
++] = running
+
5243 atomic64_read(&event
->child_total_time_running
);
5245 if (read_format
& PERF_FORMAT_ID
)
5246 values
[n
++] = primary_event_id(event
);
5248 __output_copy(handle
, values
, n
* sizeof(u64
));
5252 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5254 static void perf_output_read_group(struct perf_output_handle
*handle
,
5255 struct perf_event
*event
,
5256 u64 enabled
, u64 running
)
5258 struct perf_event
*leader
= event
->group_leader
, *sub
;
5259 u64 read_format
= event
->attr
.read_format
;
5263 values
[n
++] = 1 + leader
->nr_siblings
;
5265 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5266 values
[n
++] = enabled
;
5268 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5269 values
[n
++] = running
;
5271 if (leader
!= event
)
5272 leader
->pmu
->read(leader
);
5274 values
[n
++] = perf_event_count(leader
);
5275 if (read_format
& PERF_FORMAT_ID
)
5276 values
[n
++] = primary_event_id(leader
);
5278 __output_copy(handle
, values
, n
* sizeof(u64
));
5280 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5283 if ((sub
!= event
) &&
5284 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5285 sub
->pmu
->read(sub
);
5287 values
[n
++] = perf_event_count(sub
);
5288 if (read_format
& PERF_FORMAT_ID
)
5289 values
[n
++] = primary_event_id(sub
);
5291 __output_copy(handle
, values
, n
* sizeof(u64
));
5295 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5296 PERF_FORMAT_TOTAL_TIME_RUNNING)
5298 static void perf_output_read(struct perf_output_handle
*handle
,
5299 struct perf_event
*event
)
5301 u64 enabled
= 0, running
= 0, now
;
5302 u64 read_format
= event
->attr
.read_format
;
5305 * compute total_time_enabled, total_time_running
5306 * based on snapshot values taken when the event
5307 * was last scheduled in.
5309 * we cannot simply called update_context_time()
5310 * because of locking issue as we are called in
5313 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5314 calc_timer_values(event
, &now
, &enabled
, &running
);
5316 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5317 perf_output_read_group(handle
, event
, enabled
, running
);
5319 perf_output_read_one(handle
, event
, enabled
, running
);
5322 void perf_output_sample(struct perf_output_handle
*handle
,
5323 struct perf_event_header
*header
,
5324 struct perf_sample_data
*data
,
5325 struct perf_event
*event
)
5327 u64 sample_type
= data
->type
;
5329 perf_output_put(handle
, *header
);
5331 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5332 perf_output_put(handle
, data
->id
);
5334 if (sample_type
& PERF_SAMPLE_IP
)
5335 perf_output_put(handle
, data
->ip
);
5337 if (sample_type
& PERF_SAMPLE_TID
)
5338 perf_output_put(handle
, data
->tid_entry
);
5340 if (sample_type
& PERF_SAMPLE_TIME
)
5341 perf_output_put(handle
, data
->time
);
5343 if (sample_type
& PERF_SAMPLE_ADDR
)
5344 perf_output_put(handle
, data
->addr
);
5346 if (sample_type
& PERF_SAMPLE_ID
)
5347 perf_output_put(handle
, data
->id
);
5349 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5350 perf_output_put(handle
, data
->stream_id
);
5352 if (sample_type
& PERF_SAMPLE_CPU
)
5353 perf_output_put(handle
, data
->cpu_entry
);
5355 if (sample_type
& PERF_SAMPLE_PERIOD
)
5356 perf_output_put(handle
, data
->period
);
5358 if (sample_type
& PERF_SAMPLE_READ
)
5359 perf_output_read(handle
, event
);
5361 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5362 if (data
->callchain
) {
5365 if (data
->callchain
)
5366 size
+= data
->callchain
->nr
;
5368 size
*= sizeof(u64
);
5370 __output_copy(handle
, data
->callchain
, size
);
5373 perf_output_put(handle
, nr
);
5377 if (sample_type
& PERF_SAMPLE_RAW
) {
5379 u32 raw_size
= data
->raw
->size
;
5380 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5381 sizeof(u64
)) - sizeof(u32
);
5384 perf_output_put(handle
, real_size
);
5385 __output_copy(handle
, data
->raw
->data
, raw_size
);
5386 if (real_size
- raw_size
)
5387 __output_copy(handle
, &zero
, real_size
- raw_size
);
5393 .size
= sizeof(u32
),
5396 perf_output_put(handle
, raw
);
5400 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5401 if (data
->br_stack
) {
5404 size
= data
->br_stack
->nr
5405 * sizeof(struct perf_branch_entry
);
5407 perf_output_put(handle
, data
->br_stack
->nr
);
5408 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5411 * we always store at least the value of nr
5414 perf_output_put(handle
, nr
);
5418 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5419 u64 abi
= data
->regs_user
.abi
;
5422 * If there are no regs to dump, notice it through
5423 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5425 perf_output_put(handle
, abi
);
5428 u64 mask
= event
->attr
.sample_regs_user
;
5429 perf_output_sample_regs(handle
,
5430 data
->regs_user
.regs
,
5435 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5436 perf_output_sample_ustack(handle
,
5437 data
->stack_user_size
,
5438 data
->regs_user
.regs
);
5441 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5442 perf_output_put(handle
, data
->weight
);
5444 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5445 perf_output_put(handle
, data
->data_src
.val
);
5447 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5448 perf_output_put(handle
, data
->txn
);
5450 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5451 u64 abi
= data
->regs_intr
.abi
;
5453 * If there are no regs to dump, notice it through
5454 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5456 perf_output_put(handle
, abi
);
5459 u64 mask
= event
->attr
.sample_regs_intr
;
5461 perf_output_sample_regs(handle
,
5462 data
->regs_intr
.regs
,
5467 if (!event
->attr
.watermark
) {
5468 int wakeup_events
= event
->attr
.wakeup_events
;
5470 if (wakeup_events
) {
5471 struct ring_buffer
*rb
= handle
->rb
;
5472 int events
= local_inc_return(&rb
->events
);
5474 if (events
>= wakeup_events
) {
5475 local_sub(wakeup_events
, &rb
->events
);
5476 local_inc(&rb
->wakeup
);
5482 void perf_prepare_sample(struct perf_event_header
*header
,
5483 struct perf_sample_data
*data
,
5484 struct perf_event
*event
,
5485 struct pt_regs
*regs
)
5487 u64 sample_type
= event
->attr
.sample_type
;
5489 header
->type
= PERF_RECORD_SAMPLE
;
5490 header
->size
= sizeof(*header
) + event
->header_size
;
5493 header
->misc
|= perf_misc_flags(regs
);
5495 __perf_event_header__init_id(header
, data
, event
);
5497 if (sample_type
& PERF_SAMPLE_IP
)
5498 data
->ip
= perf_instruction_pointer(regs
);
5500 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5503 data
->callchain
= perf_callchain(event
, regs
);
5505 if (data
->callchain
)
5506 size
+= data
->callchain
->nr
;
5508 header
->size
+= size
* sizeof(u64
);
5511 if (sample_type
& PERF_SAMPLE_RAW
) {
5512 int size
= sizeof(u32
);
5515 size
+= data
->raw
->size
;
5517 size
+= sizeof(u32
);
5519 header
->size
+= round_up(size
, sizeof(u64
));
5522 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5523 int size
= sizeof(u64
); /* nr */
5524 if (data
->br_stack
) {
5525 size
+= data
->br_stack
->nr
5526 * sizeof(struct perf_branch_entry
);
5528 header
->size
+= size
;
5531 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5532 perf_sample_regs_user(&data
->regs_user
, regs
,
5533 &data
->regs_user_copy
);
5535 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5536 /* regs dump ABI info */
5537 int size
= sizeof(u64
);
5539 if (data
->regs_user
.regs
) {
5540 u64 mask
= event
->attr
.sample_regs_user
;
5541 size
+= hweight64(mask
) * sizeof(u64
);
5544 header
->size
+= size
;
5547 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5549 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5550 * processed as the last one or have additional check added
5551 * in case new sample type is added, because we could eat
5552 * up the rest of the sample size.
5554 u16 stack_size
= event
->attr
.sample_stack_user
;
5555 u16 size
= sizeof(u64
);
5557 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5558 data
->regs_user
.regs
);
5561 * If there is something to dump, add space for the dump
5562 * itself and for the field that tells the dynamic size,
5563 * which is how many have been actually dumped.
5566 size
+= sizeof(u64
) + stack_size
;
5568 data
->stack_user_size
= stack_size
;
5569 header
->size
+= size
;
5572 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5573 /* regs dump ABI info */
5574 int size
= sizeof(u64
);
5576 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5578 if (data
->regs_intr
.regs
) {
5579 u64 mask
= event
->attr
.sample_regs_intr
;
5581 size
+= hweight64(mask
) * sizeof(u64
);
5584 header
->size
+= size
;
5588 void perf_event_output(struct perf_event
*event
,
5589 struct perf_sample_data
*data
,
5590 struct pt_regs
*regs
)
5592 struct perf_output_handle handle
;
5593 struct perf_event_header header
;
5595 /* protect the callchain buffers */
5598 perf_prepare_sample(&header
, data
, event
, regs
);
5600 if (perf_output_begin(&handle
, event
, header
.size
))
5603 perf_output_sample(&handle
, &header
, data
, event
);
5605 perf_output_end(&handle
);
5615 struct perf_read_event
{
5616 struct perf_event_header header
;
5623 perf_event_read_event(struct perf_event
*event
,
5624 struct task_struct
*task
)
5626 struct perf_output_handle handle
;
5627 struct perf_sample_data sample
;
5628 struct perf_read_event read_event
= {
5630 .type
= PERF_RECORD_READ
,
5632 .size
= sizeof(read_event
) + event
->read_size
,
5634 .pid
= perf_event_pid(event
, task
),
5635 .tid
= perf_event_tid(event
, task
),
5639 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5640 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5644 perf_output_put(&handle
, read_event
);
5645 perf_output_read(&handle
, event
);
5646 perf_event__output_id_sample(event
, &handle
, &sample
);
5648 perf_output_end(&handle
);
5651 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5654 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5655 perf_event_aux_output_cb output
,
5658 struct perf_event
*event
;
5660 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5661 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5663 if (!event_filter_match(event
))
5665 output(event
, data
);
5670 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5671 struct perf_event_context
*task_ctx
)
5673 struct perf_cpu_context
*cpuctx
;
5674 struct perf_event_context
*ctx
;
5679 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5680 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5681 if (cpuctx
->unique_pmu
!= pmu
)
5683 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5686 ctxn
= pmu
->task_ctx_nr
;
5689 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5691 perf_event_aux_ctx(ctx
, output
, data
);
5693 put_cpu_ptr(pmu
->pmu_cpu_context
);
5698 perf_event_aux_ctx(task_ctx
, output
, data
);
5705 * task tracking -- fork/exit
5707 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5710 struct perf_task_event
{
5711 struct task_struct
*task
;
5712 struct perf_event_context
*task_ctx
;
5715 struct perf_event_header header
;
5725 static int perf_event_task_match(struct perf_event
*event
)
5727 return event
->attr
.comm
|| event
->attr
.mmap
||
5728 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5732 static void perf_event_task_output(struct perf_event
*event
,
5735 struct perf_task_event
*task_event
= data
;
5736 struct perf_output_handle handle
;
5737 struct perf_sample_data sample
;
5738 struct task_struct
*task
= task_event
->task
;
5739 int ret
, size
= task_event
->event_id
.header
.size
;
5741 if (!perf_event_task_match(event
))
5744 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5746 ret
= perf_output_begin(&handle
, event
,
5747 task_event
->event_id
.header
.size
);
5751 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5752 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5754 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5755 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5757 task_event
->event_id
.time
= perf_event_clock(event
);
5759 perf_output_put(&handle
, task_event
->event_id
);
5761 perf_event__output_id_sample(event
, &handle
, &sample
);
5763 perf_output_end(&handle
);
5765 task_event
->event_id
.header
.size
= size
;
5768 static void perf_event_task(struct task_struct
*task
,
5769 struct perf_event_context
*task_ctx
,
5772 struct perf_task_event task_event
;
5774 if (!atomic_read(&nr_comm_events
) &&
5775 !atomic_read(&nr_mmap_events
) &&
5776 !atomic_read(&nr_task_events
))
5779 task_event
= (struct perf_task_event
){
5781 .task_ctx
= task_ctx
,
5784 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5786 .size
= sizeof(task_event
.event_id
),
5796 perf_event_aux(perf_event_task_output
,
5801 void perf_event_fork(struct task_struct
*task
)
5803 perf_event_task(task
, NULL
, 1);
5810 struct perf_comm_event
{
5811 struct task_struct
*task
;
5816 struct perf_event_header header
;
5823 static int perf_event_comm_match(struct perf_event
*event
)
5825 return event
->attr
.comm
;
5828 static void perf_event_comm_output(struct perf_event
*event
,
5831 struct perf_comm_event
*comm_event
= data
;
5832 struct perf_output_handle handle
;
5833 struct perf_sample_data sample
;
5834 int size
= comm_event
->event_id
.header
.size
;
5837 if (!perf_event_comm_match(event
))
5840 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5841 ret
= perf_output_begin(&handle
, event
,
5842 comm_event
->event_id
.header
.size
);
5847 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5848 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5850 perf_output_put(&handle
, comm_event
->event_id
);
5851 __output_copy(&handle
, comm_event
->comm
,
5852 comm_event
->comm_size
);
5854 perf_event__output_id_sample(event
, &handle
, &sample
);
5856 perf_output_end(&handle
);
5858 comm_event
->event_id
.header
.size
= size
;
5861 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5863 char comm
[TASK_COMM_LEN
];
5866 memset(comm
, 0, sizeof(comm
));
5867 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5868 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5870 comm_event
->comm
= comm
;
5871 comm_event
->comm_size
= size
;
5873 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5875 perf_event_aux(perf_event_comm_output
,
5880 void perf_event_comm(struct task_struct
*task
, bool exec
)
5882 struct perf_comm_event comm_event
;
5884 if (!atomic_read(&nr_comm_events
))
5887 comm_event
= (struct perf_comm_event
){
5893 .type
= PERF_RECORD_COMM
,
5894 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5902 perf_event_comm_event(&comm_event
);
5909 struct perf_mmap_event
{
5910 struct vm_area_struct
*vma
;
5912 const char *file_name
;
5920 struct perf_event_header header
;
5930 static int perf_event_mmap_match(struct perf_event
*event
,
5933 struct perf_mmap_event
*mmap_event
= data
;
5934 struct vm_area_struct
*vma
= mmap_event
->vma
;
5935 int executable
= vma
->vm_flags
& VM_EXEC
;
5937 return (!executable
&& event
->attr
.mmap_data
) ||
5938 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5941 static void perf_event_mmap_output(struct perf_event
*event
,
5944 struct perf_mmap_event
*mmap_event
= data
;
5945 struct perf_output_handle handle
;
5946 struct perf_sample_data sample
;
5947 int size
= mmap_event
->event_id
.header
.size
;
5950 if (!perf_event_mmap_match(event
, data
))
5953 if (event
->attr
.mmap2
) {
5954 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5955 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5956 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5957 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5958 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5959 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5960 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5963 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5964 ret
= perf_output_begin(&handle
, event
,
5965 mmap_event
->event_id
.header
.size
);
5969 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5970 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5972 perf_output_put(&handle
, mmap_event
->event_id
);
5974 if (event
->attr
.mmap2
) {
5975 perf_output_put(&handle
, mmap_event
->maj
);
5976 perf_output_put(&handle
, mmap_event
->min
);
5977 perf_output_put(&handle
, mmap_event
->ino
);
5978 perf_output_put(&handle
, mmap_event
->ino_generation
);
5979 perf_output_put(&handle
, mmap_event
->prot
);
5980 perf_output_put(&handle
, mmap_event
->flags
);
5983 __output_copy(&handle
, mmap_event
->file_name
,
5984 mmap_event
->file_size
);
5986 perf_event__output_id_sample(event
, &handle
, &sample
);
5988 perf_output_end(&handle
);
5990 mmap_event
->event_id
.header
.size
= size
;
5993 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5995 struct vm_area_struct
*vma
= mmap_event
->vma
;
5996 struct file
*file
= vma
->vm_file
;
5997 int maj
= 0, min
= 0;
5998 u64 ino
= 0, gen
= 0;
5999 u32 prot
= 0, flags
= 0;
6006 struct inode
*inode
;
6009 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6015 * d_path() works from the end of the rb backwards, so we
6016 * need to add enough zero bytes after the string to handle
6017 * the 64bit alignment we do later.
6019 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6024 inode
= file_inode(vma
->vm_file
);
6025 dev
= inode
->i_sb
->s_dev
;
6027 gen
= inode
->i_generation
;
6031 if (vma
->vm_flags
& VM_READ
)
6033 if (vma
->vm_flags
& VM_WRITE
)
6035 if (vma
->vm_flags
& VM_EXEC
)
6038 if (vma
->vm_flags
& VM_MAYSHARE
)
6041 flags
= MAP_PRIVATE
;
6043 if (vma
->vm_flags
& VM_DENYWRITE
)
6044 flags
|= MAP_DENYWRITE
;
6045 if (vma
->vm_flags
& VM_MAYEXEC
)
6046 flags
|= MAP_EXECUTABLE
;
6047 if (vma
->vm_flags
& VM_LOCKED
)
6048 flags
|= MAP_LOCKED
;
6049 if (vma
->vm_flags
& VM_HUGETLB
)
6050 flags
|= MAP_HUGETLB
;
6054 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6055 name
= (char *) vma
->vm_ops
->name(vma
);
6060 name
= (char *)arch_vma_name(vma
);
6064 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6065 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6069 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6070 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6080 strlcpy(tmp
, name
, sizeof(tmp
));
6084 * Since our buffer works in 8 byte units we need to align our string
6085 * size to a multiple of 8. However, we must guarantee the tail end is
6086 * zero'd out to avoid leaking random bits to userspace.
6088 size
= strlen(name
)+1;
6089 while (!IS_ALIGNED(size
, sizeof(u64
)))
6090 name
[size
++] = '\0';
6092 mmap_event
->file_name
= name
;
6093 mmap_event
->file_size
= size
;
6094 mmap_event
->maj
= maj
;
6095 mmap_event
->min
= min
;
6096 mmap_event
->ino
= ino
;
6097 mmap_event
->ino_generation
= gen
;
6098 mmap_event
->prot
= prot
;
6099 mmap_event
->flags
= flags
;
6101 if (!(vma
->vm_flags
& VM_EXEC
))
6102 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6104 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6106 perf_event_aux(perf_event_mmap_output
,
6113 void perf_event_mmap(struct vm_area_struct
*vma
)
6115 struct perf_mmap_event mmap_event
;
6117 if (!atomic_read(&nr_mmap_events
))
6120 mmap_event
= (struct perf_mmap_event
){
6126 .type
= PERF_RECORD_MMAP
,
6127 .misc
= PERF_RECORD_MISC_USER
,
6132 .start
= vma
->vm_start
,
6133 .len
= vma
->vm_end
- vma
->vm_start
,
6134 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6136 /* .maj (attr_mmap2 only) */
6137 /* .min (attr_mmap2 only) */
6138 /* .ino (attr_mmap2 only) */
6139 /* .ino_generation (attr_mmap2 only) */
6140 /* .prot (attr_mmap2 only) */
6141 /* .flags (attr_mmap2 only) */
6144 perf_event_mmap_event(&mmap_event
);
6147 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6148 unsigned long size
, u64 flags
)
6150 struct perf_output_handle handle
;
6151 struct perf_sample_data sample
;
6152 struct perf_aux_event
{
6153 struct perf_event_header header
;
6159 .type
= PERF_RECORD_AUX
,
6161 .size
= sizeof(rec
),
6169 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6170 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6175 perf_output_put(&handle
, rec
);
6176 perf_event__output_id_sample(event
, &handle
, &sample
);
6178 perf_output_end(&handle
);
6182 * Lost/dropped samples logging
6184 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6186 struct perf_output_handle handle
;
6187 struct perf_sample_data sample
;
6191 struct perf_event_header header
;
6193 } lost_samples_event
= {
6195 .type
= PERF_RECORD_LOST_SAMPLES
,
6197 .size
= sizeof(lost_samples_event
),
6202 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6204 ret
= perf_output_begin(&handle
, event
,
6205 lost_samples_event
.header
.size
);
6209 perf_output_put(&handle
, lost_samples_event
);
6210 perf_event__output_id_sample(event
, &handle
, &sample
);
6211 perf_output_end(&handle
);
6215 * context_switch tracking
6218 struct perf_switch_event
{
6219 struct task_struct
*task
;
6220 struct task_struct
*next_prev
;
6223 struct perf_event_header header
;
6229 static int perf_event_switch_match(struct perf_event
*event
)
6231 return event
->attr
.context_switch
;
6234 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6236 struct perf_switch_event
*se
= data
;
6237 struct perf_output_handle handle
;
6238 struct perf_sample_data sample
;
6241 if (!perf_event_switch_match(event
))
6244 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6245 if (event
->ctx
->task
) {
6246 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6247 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6249 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6250 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6251 se
->event_id
.next_prev_pid
=
6252 perf_event_pid(event
, se
->next_prev
);
6253 se
->event_id
.next_prev_tid
=
6254 perf_event_tid(event
, se
->next_prev
);
6257 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6259 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6263 if (event
->ctx
->task
)
6264 perf_output_put(&handle
, se
->event_id
.header
);
6266 perf_output_put(&handle
, se
->event_id
);
6268 perf_event__output_id_sample(event
, &handle
, &sample
);
6270 perf_output_end(&handle
);
6273 static void perf_event_switch(struct task_struct
*task
,
6274 struct task_struct
*next_prev
, bool sched_in
)
6276 struct perf_switch_event switch_event
;
6278 /* N.B. caller checks nr_switch_events != 0 */
6280 switch_event
= (struct perf_switch_event
){
6282 .next_prev
= next_prev
,
6286 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6289 /* .next_prev_pid */
6290 /* .next_prev_tid */
6294 perf_event_aux(perf_event_switch_output
,
6300 * IRQ throttle logging
6303 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6305 struct perf_output_handle handle
;
6306 struct perf_sample_data sample
;
6310 struct perf_event_header header
;
6314 } throttle_event
= {
6316 .type
= PERF_RECORD_THROTTLE
,
6318 .size
= sizeof(throttle_event
),
6320 .time
= perf_event_clock(event
),
6321 .id
= primary_event_id(event
),
6322 .stream_id
= event
->id
,
6326 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6328 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6330 ret
= perf_output_begin(&handle
, event
,
6331 throttle_event
.header
.size
);
6335 perf_output_put(&handle
, throttle_event
);
6336 perf_event__output_id_sample(event
, &handle
, &sample
);
6337 perf_output_end(&handle
);
6340 static void perf_log_itrace_start(struct perf_event
*event
)
6342 struct perf_output_handle handle
;
6343 struct perf_sample_data sample
;
6344 struct perf_aux_event
{
6345 struct perf_event_header header
;
6352 event
= event
->parent
;
6354 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6355 event
->hw
.itrace_started
)
6358 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6359 rec
.header
.misc
= 0;
6360 rec
.header
.size
= sizeof(rec
);
6361 rec
.pid
= perf_event_pid(event
, current
);
6362 rec
.tid
= perf_event_tid(event
, current
);
6364 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6365 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6370 perf_output_put(&handle
, rec
);
6371 perf_event__output_id_sample(event
, &handle
, &sample
);
6373 perf_output_end(&handle
);
6377 * Generic event overflow handling, sampling.
6380 static int __perf_event_overflow(struct perf_event
*event
,
6381 int throttle
, struct perf_sample_data
*data
,
6382 struct pt_regs
*regs
)
6384 int events
= atomic_read(&event
->event_limit
);
6385 struct hw_perf_event
*hwc
= &event
->hw
;
6390 * Non-sampling counters might still use the PMI to fold short
6391 * hardware counters, ignore those.
6393 if (unlikely(!is_sampling_event(event
)))
6396 seq
= __this_cpu_read(perf_throttled_seq
);
6397 if (seq
!= hwc
->interrupts_seq
) {
6398 hwc
->interrupts_seq
= seq
;
6399 hwc
->interrupts
= 1;
6402 if (unlikely(throttle
6403 && hwc
->interrupts
>= max_samples_per_tick
)) {
6404 __this_cpu_inc(perf_throttled_count
);
6405 hwc
->interrupts
= MAX_INTERRUPTS
;
6406 perf_log_throttle(event
, 0);
6407 tick_nohz_full_kick();
6412 if (event
->attr
.freq
) {
6413 u64 now
= perf_clock();
6414 s64 delta
= now
- hwc
->freq_time_stamp
;
6416 hwc
->freq_time_stamp
= now
;
6418 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6419 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6423 * XXX event_limit might not quite work as expected on inherited
6427 event
->pending_kill
= POLL_IN
;
6428 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6430 event
->pending_kill
= POLL_HUP
;
6431 event
->pending_disable
= 1;
6432 irq_work_queue(&event
->pending
);
6435 if (event
->overflow_handler
)
6436 event
->overflow_handler(event
, data
, regs
);
6438 perf_event_output(event
, data
, regs
);
6440 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6441 event
->pending_wakeup
= 1;
6442 irq_work_queue(&event
->pending
);
6448 int perf_event_overflow(struct perf_event
*event
,
6449 struct perf_sample_data
*data
,
6450 struct pt_regs
*regs
)
6452 return __perf_event_overflow(event
, 1, data
, regs
);
6456 * Generic software event infrastructure
6459 struct swevent_htable
{
6460 struct swevent_hlist
*swevent_hlist
;
6461 struct mutex hlist_mutex
;
6464 /* Recursion avoidance in each contexts */
6465 int recursion
[PERF_NR_CONTEXTS
];
6467 /* Keeps track of cpu being initialized/exited */
6471 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6474 * We directly increment event->count and keep a second value in
6475 * event->hw.period_left to count intervals. This period event
6476 * is kept in the range [-sample_period, 0] so that we can use the
6480 u64
perf_swevent_set_period(struct perf_event
*event
)
6482 struct hw_perf_event
*hwc
= &event
->hw
;
6483 u64 period
= hwc
->last_period
;
6487 hwc
->last_period
= hwc
->sample_period
;
6490 old
= val
= local64_read(&hwc
->period_left
);
6494 nr
= div64_u64(period
+ val
, period
);
6495 offset
= nr
* period
;
6497 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6503 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6504 struct perf_sample_data
*data
,
6505 struct pt_regs
*regs
)
6507 struct hw_perf_event
*hwc
= &event
->hw
;
6511 overflow
= perf_swevent_set_period(event
);
6513 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6516 for (; overflow
; overflow
--) {
6517 if (__perf_event_overflow(event
, throttle
,
6520 * We inhibit the overflow from happening when
6521 * hwc->interrupts == MAX_INTERRUPTS.
6529 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6530 struct perf_sample_data
*data
,
6531 struct pt_regs
*regs
)
6533 struct hw_perf_event
*hwc
= &event
->hw
;
6535 local64_add(nr
, &event
->count
);
6540 if (!is_sampling_event(event
))
6543 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6545 return perf_swevent_overflow(event
, 1, data
, regs
);
6547 data
->period
= event
->hw
.last_period
;
6549 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6550 return perf_swevent_overflow(event
, 1, data
, regs
);
6552 if (local64_add_negative(nr
, &hwc
->period_left
))
6555 perf_swevent_overflow(event
, 0, data
, regs
);
6558 static int perf_exclude_event(struct perf_event
*event
,
6559 struct pt_regs
*regs
)
6561 if (event
->hw
.state
& PERF_HES_STOPPED
)
6565 if (event
->attr
.exclude_user
&& user_mode(regs
))
6568 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6575 static int perf_swevent_match(struct perf_event
*event
,
6576 enum perf_type_id type
,
6578 struct perf_sample_data
*data
,
6579 struct pt_regs
*regs
)
6581 if (event
->attr
.type
!= type
)
6584 if (event
->attr
.config
!= event_id
)
6587 if (perf_exclude_event(event
, regs
))
6593 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6595 u64 val
= event_id
| (type
<< 32);
6597 return hash_64(val
, SWEVENT_HLIST_BITS
);
6600 static inline struct hlist_head
*
6601 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6603 u64 hash
= swevent_hash(type
, event_id
);
6605 return &hlist
->heads
[hash
];
6608 /* For the read side: events when they trigger */
6609 static inline struct hlist_head
*
6610 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6612 struct swevent_hlist
*hlist
;
6614 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6618 return __find_swevent_head(hlist
, type
, event_id
);
6621 /* For the event head insertion and removal in the hlist */
6622 static inline struct hlist_head
*
6623 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6625 struct swevent_hlist
*hlist
;
6626 u32 event_id
= event
->attr
.config
;
6627 u64 type
= event
->attr
.type
;
6630 * Event scheduling is always serialized against hlist allocation
6631 * and release. Which makes the protected version suitable here.
6632 * The context lock guarantees that.
6634 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6635 lockdep_is_held(&event
->ctx
->lock
));
6639 return __find_swevent_head(hlist
, type
, event_id
);
6642 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6644 struct perf_sample_data
*data
,
6645 struct pt_regs
*regs
)
6647 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6648 struct perf_event
*event
;
6649 struct hlist_head
*head
;
6652 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6656 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6657 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6658 perf_swevent_event(event
, nr
, data
, regs
);
6664 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6666 int perf_swevent_get_recursion_context(void)
6668 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6670 return get_recursion_context(swhash
->recursion
);
6672 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6674 inline void perf_swevent_put_recursion_context(int rctx
)
6676 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6678 put_recursion_context(swhash
->recursion
, rctx
);
6681 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6683 struct perf_sample_data data
;
6685 if (WARN_ON_ONCE(!regs
))
6688 perf_sample_data_init(&data
, addr
, 0);
6689 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6692 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6696 preempt_disable_notrace();
6697 rctx
= perf_swevent_get_recursion_context();
6698 if (unlikely(rctx
< 0))
6701 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6703 perf_swevent_put_recursion_context(rctx
);
6705 preempt_enable_notrace();
6708 static void perf_swevent_read(struct perf_event
*event
)
6712 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6714 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6715 struct hw_perf_event
*hwc
= &event
->hw
;
6716 struct hlist_head
*head
;
6718 if (is_sampling_event(event
)) {
6719 hwc
->last_period
= hwc
->sample_period
;
6720 perf_swevent_set_period(event
);
6723 hwc
->state
= !(flags
& PERF_EF_START
);
6725 head
= find_swevent_head(swhash
, event
);
6728 * We can race with cpu hotplug code. Do not
6729 * WARN if the cpu just got unplugged.
6731 WARN_ON_ONCE(swhash
->online
);
6735 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6736 perf_event_update_userpage(event
);
6741 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6743 hlist_del_rcu(&event
->hlist_entry
);
6746 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6748 event
->hw
.state
= 0;
6751 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6753 event
->hw
.state
= PERF_HES_STOPPED
;
6756 /* Deref the hlist from the update side */
6757 static inline struct swevent_hlist
*
6758 swevent_hlist_deref(struct swevent_htable
*swhash
)
6760 return rcu_dereference_protected(swhash
->swevent_hlist
,
6761 lockdep_is_held(&swhash
->hlist_mutex
));
6764 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6766 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6771 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6772 kfree_rcu(hlist
, rcu_head
);
6775 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6777 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6779 mutex_lock(&swhash
->hlist_mutex
);
6781 if (!--swhash
->hlist_refcount
)
6782 swevent_hlist_release(swhash
);
6784 mutex_unlock(&swhash
->hlist_mutex
);
6787 static void swevent_hlist_put(struct perf_event
*event
)
6791 for_each_possible_cpu(cpu
)
6792 swevent_hlist_put_cpu(event
, cpu
);
6795 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6797 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6800 mutex_lock(&swhash
->hlist_mutex
);
6802 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6803 struct swevent_hlist
*hlist
;
6805 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6810 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6812 swhash
->hlist_refcount
++;
6814 mutex_unlock(&swhash
->hlist_mutex
);
6819 static int swevent_hlist_get(struct perf_event
*event
)
6822 int cpu
, failed_cpu
;
6825 for_each_possible_cpu(cpu
) {
6826 err
= swevent_hlist_get_cpu(event
, cpu
);
6836 for_each_possible_cpu(cpu
) {
6837 if (cpu
== failed_cpu
)
6839 swevent_hlist_put_cpu(event
, cpu
);
6846 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6848 static void sw_perf_event_destroy(struct perf_event
*event
)
6850 u64 event_id
= event
->attr
.config
;
6852 WARN_ON(event
->parent
);
6854 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6855 swevent_hlist_put(event
);
6858 static int perf_swevent_init(struct perf_event
*event
)
6860 u64 event_id
= event
->attr
.config
;
6862 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6866 * no branch sampling for software events
6868 if (has_branch_stack(event
))
6872 case PERF_COUNT_SW_CPU_CLOCK
:
6873 case PERF_COUNT_SW_TASK_CLOCK
:
6880 if (event_id
>= PERF_COUNT_SW_MAX
)
6883 if (!event
->parent
) {
6886 err
= swevent_hlist_get(event
);
6890 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6891 event
->destroy
= sw_perf_event_destroy
;
6897 static struct pmu perf_swevent
= {
6898 .task_ctx_nr
= perf_sw_context
,
6900 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6902 .event_init
= perf_swevent_init
,
6903 .add
= perf_swevent_add
,
6904 .del
= perf_swevent_del
,
6905 .start
= perf_swevent_start
,
6906 .stop
= perf_swevent_stop
,
6907 .read
= perf_swevent_read
,
6910 #ifdef CONFIG_EVENT_TRACING
6912 static int perf_tp_filter_match(struct perf_event
*event
,
6913 struct perf_sample_data
*data
)
6915 void *record
= data
->raw
->data
;
6917 /* only top level events have filters set */
6919 event
= event
->parent
;
6921 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6926 static int perf_tp_event_match(struct perf_event
*event
,
6927 struct perf_sample_data
*data
,
6928 struct pt_regs
*regs
)
6930 if (event
->hw
.state
& PERF_HES_STOPPED
)
6933 * All tracepoints are from kernel-space.
6935 if (event
->attr
.exclude_kernel
)
6938 if (!perf_tp_filter_match(event
, data
))
6944 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6945 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6946 struct task_struct
*task
)
6948 struct perf_sample_data data
;
6949 struct perf_event
*event
;
6951 struct perf_raw_record raw
= {
6956 perf_sample_data_init(&data
, addr
, 0);
6959 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6960 if (perf_tp_event_match(event
, &data
, regs
))
6961 perf_swevent_event(event
, count
, &data
, regs
);
6965 * If we got specified a target task, also iterate its context and
6966 * deliver this event there too.
6968 if (task
&& task
!= current
) {
6969 struct perf_event_context
*ctx
;
6970 struct trace_entry
*entry
= record
;
6973 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6977 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6978 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6980 if (event
->attr
.config
!= entry
->type
)
6982 if (perf_tp_event_match(event
, &data
, regs
))
6983 perf_swevent_event(event
, count
, &data
, regs
);
6989 perf_swevent_put_recursion_context(rctx
);
6991 EXPORT_SYMBOL_GPL(perf_tp_event
);
6993 static void tp_perf_event_destroy(struct perf_event
*event
)
6995 perf_trace_destroy(event
);
6998 static int perf_tp_event_init(struct perf_event
*event
)
7002 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7006 * no branch sampling for tracepoint events
7008 if (has_branch_stack(event
))
7011 err
= perf_trace_init(event
);
7015 event
->destroy
= tp_perf_event_destroy
;
7020 static struct pmu perf_tracepoint
= {
7021 .task_ctx_nr
= perf_sw_context
,
7023 .event_init
= perf_tp_event_init
,
7024 .add
= perf_trace_add
,
7025 .del
= perf_trace_del
,
7026 .start
= perf_swevent_start
,
7027 .stop
= perf_swevent_stop
,
7028 .read
= perf_swevent_read
,
7031 static inline void perf_tp_register(void)
7033 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7036 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7041 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7044 filter_str
= strndup_user(arg
, PAGE_SIZE
);
7045 if (IS_ERR(filter_str
))
7046 return PTR_ERR(filter_str
);
7048 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7054 static void perf_event_free_filter(struct perf_event
*event
)
7056 ftrace_profile_free_filter(event
);
7059 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7061 struct bpf_prog
*prog
;
7063 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7066 if (event
->tp_event
->prog
)
7069 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7070 /* bpf programs can only be attached to u/kprobes */
7073 prog
= bpf_prog_get(prog_fd
);
7075 return PTR_ERR(prog
);
7077 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7078 /* valid fd, but invalid bpf program type */
7083 event
->tp_event
->prog
= prog
;
7088 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7090 struct bpf_prog
*prog
;
7092 if (!event
->tp_event
)
7095 prog
= event
->tp_event
->prog
;
7097 event
->tp_event
->prog
= NULL
;
7104 static inline void perf_tp_register(void)
7108 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7113 static void perf_event_free_filter(struct perf_event
*event
)
7117 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7122 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7125 #endif /* CONFIG_EVENT_TRACING */
7127 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7128 void perf_bp_event(struct perf_event
*bp
, void *data
)
7130 struct perf_sample_data sample
;
7131 struct pt_regs
*regs
= data
;
7133 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7135 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7136 perf_swevent_event(bp
, 1, &sample
, regs
);
7141 * hrtimer based swevent callback
7144 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7146 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7147 struct perf_sample_data data
;
7148 struct pt_regs
*regs
;
7149 struct perf_event
*event
;
7152 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7154 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7155 return HRTIMER_NORESTART
;
7157 event
->pmu
->read(event
);
7159 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7160 regs
= get_irq_regs();
7162 if (regs
&& !perf_exclude_event(event
, regs
)) {
7163 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7164 if (__perf_event_overflow(event
, 1, &data
, regs
))
7165 ret
= HRTIMER_NORESTART
;
7168 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7169 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7174 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7176 struct hw_perf_event
*hwc
= &event
->hw
;
7179 if (!is_sampling_event(event
))
7182 period
= local64_read(&hwc
->period_left
);
7187 local64_set(&hwc
->period_left
, 0);
7189 period
= max_t(u64
, 10000, hwc
->sample_period
);
7191 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7192 HRTIMER_MODE_REL_PINNED
);
7195 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7197 struct hw_perf_event
*hwc
= &event
->hw
;
7199 if (is_sampling_event(event
)) {
7200 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7201 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7203 hrtimer_cancel(&hwc
->hrtimer
);
7207 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7209 struct hw_perf_event
*hwc
= &event
->hw
;
7211 if (!is_sampling_event(event
))
7214 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7215 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7218 * Since hrtimers have a fixed rate, we can do a static freq->period
7219 * mapping and avoid the whole period adjust feedback stuff.
7221 if (event
->attr
.freq
) {
7222 long freq
= event
->attr
.sample_freq
;
7224 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7225 hwc
->sample_period
= event
->attr
.sample_period
;
7226 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7227 hwc
->last_period
= hwc
->sample_period
;
7228 event
->attr
.freq
= 0;
7233 * Software event: cpu wall time clock
7236 static void cpu_clock_event_update(struct perf_event
*event
)
7241 now
= local_clock();
7242 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7243 local64_add(now
- prev
, &event
->count
);
7246 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7248 local64_set(&event
->hw
.prev_count
, local_clock());
7249 perf_swevent_start_hrtimer(event
);
7252 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7254 perf_swevent_cancel_hrtimer(event
);
7255 cpu_clock_event_update(event
);
7258 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7260 if (flags
& PERF_EF_START
)
7261 cpu_clock_event_start(event
, flags
);
7262 perf_event_update_userpage(event
);
7267 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7269 cpu_clock_event_stop(event
, flags
);
7272 static void cpu_clock_event_read(struct perf_event
*event
)
7274 cpu_clock_event_update(event
);
7277 static int cpu_clock_event_init(struct perf_event
*event
)
7279 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7282 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7286 * no branch sampling for software events
7288 if (has_branch_stack(event
))
7291 perf_swevent_init_hrtimer(event
);
7296 static struct pmu perf_cpu_clock
= {
7297 .task_ctx_nr
= perf_sw_context
,
7299 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7301 .event_init
= cpu_clock_event_init
,
7302 .add
= cpu_clock_event_add
,
7303 .del
= cpu_clock_event_del
,
7304 .start
= cpu_clock_event_start
,
7305 .stop
= cpu_clock_event_stop
,
7306 .read
= cpu_clock_event_read
,
7310 * Software event: task time clock
7313 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7318 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7320 local64_add(delta
, &event
->count
);
7323 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7325 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7326 perf_swevent_start_hrtimer(event
);
7329 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7331 perf_swevent_cancel_hrtimer(event
);
7332 task_clock_event_update(event
, event
->ctx
->time
);
7335 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7337 if (flags
& PERF_EF_START
)
7338 task_clock_event_start(event
, flags
);
7339 perf_event_update_userpage(event
);
7344 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7346 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7349 static void task_clock_event_read(struct perf_event
*event
)
7351 u64 now
= perf_clock();
7352 u64 delta
= now
- event
->ctx
->timestamp
;
7353 u64 time
= event
->ctx
->time
+ delta
;
7355 task_clock_event_update(event
, time
);
7358 static int task_clock_event_init(struct perf_event
*event
)
7360 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7363 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7367 * no branch sampling for software events
7369 if (has_branch_stack(event
))
7372 perf_swevent_init_hrtimer(event
);
7377 static struct pmu perf_task_clock
= {
7378 .task_ctx_nr
= perf_sw_context
,
7380 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7382 .event_init
= task_clock_event_init
,
7383 .add
= task_clock_event_add
,
7384 .del
= task_clock_event_del
,
7385 .start
= task_clock_event_start
,
7386 .stop
= task_clock_event_stop
,
7387 .read
= task_clock_event_read
,
7390 static void perf_pmu_nop_void(struct pmu
*pmu
)
7394 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7398 static int perf_pmu_nop_int(struct pmu
*pmu
)
7403 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7405 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7407 __this_cpu_write(nop_txn_flags
, flags
);
7409 if (flags
& ~PERF_PMU_TXN_ADD
)
7412 perf_pmu_disable(pmu
);
7415 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7417 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7419 __this_cpu_write(nop_txn_flags
, 0);
7421 if (flags
& ~PERF_PMU_TXN_ADD
)
7424 perf_pmu_enable(pmu
);
7428 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7430 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7432 __this_cpu_write(nop_txn_flags
, 0);
7434 if (flags
& ~PERF_PMU_TXN_ADD
)
7437 perf_pmu_enable(pmu
);
7440 static int perf_event_idx_default(struct perf_event
*event
)
7446 * Ensures all contexts with the same task_ctx_nr have the same
7447 * pmu_cpu_context too.
7449 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7456 list_for_each_entry(pmu
, &pmus
, entry
) {
7457 if (pmu
->task_ctx_nr
== ctxn
)
7458 return pmu
->pmu_cpu_context
;
7464 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7468 for_each_possible_cpu(cpu
) {
7469 struct perf_cpu_context
*cpuctx
;
7471 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7473 if (cpuctx
->unique_pmu
== old_pmu
)
7474 cpuctx
->unique_pmu
= pmu
;
7478 static void free_pmu_context(struct pmu
*pmu
)
7482 mutex_lock(&pmus_lock
);
7484 * Like a real lame refcount.
7486 list_for_each_entry(i
, &pmus
, entry
) {
7487 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7488 update_pmu_context(i
, pmu
);
7493 free_percpu(pmu
->pmu_cpu_context
);
7495 mutex_unlock(&pmus_lock
);
7497 static struct idr pmu_idr
;
7500 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7502 struct pmu
*pmu
= dev_get_drvdata(dev
);
7504 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7506 static DEVICE_ATTR_RO(type
);
7509 perf_event_mux_interval_ms_show(struct device
*dev
,
7510 struct device_attribute
*attr
,
7513 struct pmu
*pmu
= dev_get_drvdata(dev
);
7515 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7518 static DEFINE_MUTEX(mux_interval_mutex
);
7521 perf_event_mux_interval_ms_store(struct device
*dev
,
7522 struct device_attribute
*attr
,
7523 const char *buf
, size_t count
)
7525 struct pmu
*pmu
= dev_get_drvdata(dev
);
7526 int timer
, cpu
, ret
;
7528 ret
= kstrtoint(buf
, 0, &timer
);
7535 /* same value, noting to do */
7536 if (timer
== pmu
->hrtimer_interval_ms
)
7539 mutex_lock(&mux_interval_mutex
);
7540 pmu
->hrtimer_interval_ms
= timer
;
7542 /* update all cpuctx for this PMU */
7544 for_each_online_cpu(cpu
) {
7545 struct perf_cpu_context
*cpuctx
;
7546 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7547 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7549 cpu_function_call(cpu
,
7550 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7553 mutex_unlock(&mux_interval_mutex
);
7557 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7559 static struct attribute
*pmu_dev_attrs
[] = {
7560 &dev_attr_type
.attr
,
7561 &dev_attr_perf_event_mux_interval_ms
.attr
,
7564 ATTRIBUTE_GROUPS(pmu_dev
);
7566 static int pmu_bus_running
;
7567 static struct bus_type pmu_bus
= {
7568 .name
= "event_source",
7569 .dev_groups
= pmu_dev_groups
,
7572 static void pmu_dev_release(struct device
*dev
)
7577 static int pmu_dev_alloc(struct pmu
*pmu
)
7581 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7585 pmu
->dev
->groups
= pmu
->attr_groups
;
7586 device_initialize(pmu
->dev
);
7587 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7591 dev_set_drvdata(pmu
->dev
, pmu
);
7592 pmu
->dev
->bus
= &pmu_bus
;
7593 pmu
->dev
->release
= pmu_dev_release
;
7594 ret
= device_add(pmu
->dev
);
7602 put_device(pmu
->dev
);
7606 static struct lock_class_key cpuctx_mutex
;
7607 static struct lock_class_key cpuctx_lock
;
7609 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7613 mutex_lock(&pmus_lock
);
7615 pmu
->pmu_disable_count
= alloc_percpu(int);
7616 if (!pmu
->pmu_disable_count
)
7625 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7633 if (pmu_bus_running
) {
7634 ret
= pmu_dev_alloc(pmu
);
7640 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7641 if (pmu
->pmu_cpu_context
)
7642 goto got_cpu_context
;
7645 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7646 if (!pmu
->pmu_cpu_context
)
7649 for_each_possible_cpu(cpu
) {
7650 struct perf_cpu_context
*cpuctx
;
7652 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7653 __perf_event_init_context(&cpuctx
->ctx
);
7654 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7655 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7656 cpuctx
->ctx
.pmu
= pmu
;
7658 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7660 cpuctx
->unique_pmu
= pmu
;
7664 if (!pmu
->start_txn
) {
7665 if (pmu
->pmu_enable
) {
7667 * If we have pmu_enable/pmu_disable calls, install
7668 * transaction stubs that use that to try and batch
7669 * hardware accesses.
7671 pmu
->start_txn
= perf_pmu_start_txn
;
7672 pmu
->commit_txn
= perf_pmu_commit_txn
;
7673 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7675 pmu
->start_txn
= perf_pmu_nop_txn
;
7676 pmu
->commit_txn
= perf_pmu_nop_int
;
7677 pmu
->cancel_txn
= perf_pmu_nop_void
;
7681 if (!pmu
->pmu_enable
) {
7682 pmu
->pmu_enable
= perf_pmu_nop_void
;
7683 pmu
->pmu_disable
= perf_pmu_nop_void
;
7686 if (!pmu
->event_idx
)
7687 pmu
->event_idx
= perf_event_idx_default
;
7689 list_add_rcu(&pmu
->entry
, &pmus
);
7690 atomic_set(&pmu
->exclusive_cnt
, 0);
7693 mutex_unlock(&pmus_lock
);
7698 device_del(pmu
->dev
);
7699 put_device(pmu
->dev
);
7702 if (pmu
->type
>= PERF_TYPE_MAX
)
7703 idr_remove(&pmu_idr
, pmu
->type
);
7706 free_percpu(pmu
->pmu_disable_count
);
7709 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7711 void perf_pmu_unregister(struct pmu
*pmu
)
7713 mutex_lock(&pmus_lock
);
7714 list_del_rcu(&pmu
->entry
);
7715 mutex_unlock(&pmus_lock
);
7718 * We dereference the pmu list under both SRCU and regular RCU, so
7719 * synchronize against both of those.
7721 synchronize_srcu(&pmus_srcu
);
7724 free_percpu(pmu
->pmu_disable_count
);
7725 if (pmu
->type
>= PERF_TYPE_MAX
)
7726 idr_remove(&pmu_idr
, pmu
->type
);
7727 device_del(pmu
->dev
);
7728 put_device(pmu
->dev
);
7729 free_pmu_context(pmu
);
7731 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7733 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7735 struct perf_event_context
*ctx
= NULL
;
7738 if (!try_module_get(pmu
->module
))
7741 if (event
->group_leader
!= event
) {
7743 * This ctx->mutex can nest when we're called through
7744 * inheritance. See the perf_event_ctx_lock_nested() comment.
7746 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7747 SINGLE_DEPTH_NESTING
);
7752 ret
= pmu
->event_init(event
);
7755 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7758 module_put(pmu
->module
);
7763 static struct pmu
*perf_init_event(struct perf_event
*event
)
7765 struct pmu
*pmu
= NULL
;
7769 idx
= srcu_read_lock(&pmus_srcu
);
7772 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7775 ret
= perf_try_init_event(pmu
, event
);
7781 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7782 ret
= perf_try_init_event(pmu
, event
);
7786 if (ret
!= -ENOENT
) {
7791 pmu
= ERR_PTR(-ENOENT
);
7793 srcu_read_unlock(&pmus_srcu
, idx
);
7798 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7803 if (is_cgroup_event(event
))
7804 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7807 static void account_event(struct perf_event
*event
)
7812 if (event
->attach_state
& PERF_ATTACH_TASK
)
7813 static_key_slow_inc(&perf_sched_events
.key
);
7814 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7815 atomic_inc(&nr_mmap_events
);
7816 if (event
->attr
.comm
)
7817 atomic_inc(&nr_comm_events
);
7818 if (event
->attr
.task
)
7819 atomic_inc(&nr_task_events
);
7820 if (event
->attr
.freq
) {
7821 if (atomic_inc_return(&nr_freq_events
) == 1)
7822 tick_nohz_full_kick_all();
7824 if (event
->attr
.context_switch
) {
7825 atomic_inc(&nr_switch_events
);
7826 static_key_slow_inc(&perf_sched_events
.key
);
7828 if (has_branch_stack(event
))
7829 static_key_slow_inc(&perf_sched_events
.key
);
7830 if (is_cgroup_event(event
))
7831 static_key_slow_inc(&perf_sched_events
.key
);
7833 account_event_cpu(event
, event
->cpu
);
7837 * Allocate and initialize a event structure
7839 static struct perf_event
*
7840 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7841 struct task_struct
*task
,
7842 struct perf_event
*group_leader
,
7843 struct perf_event
*parent_event
,
7844 perf_overflow_handler_t overflow_handler
,
7845 void *context
, int cgroup_fd
)
7848 struct perf_event
*event
;
7849 struct hw_perf_event
*hwc
;
7852 if ((unsigned)cpu
>= nr_cpu_ids
) {
7853 if (!task
|| cpu
!= -1)
7854 return ERR_PTR(-EINVAL
);
7857 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7859 return ERR_PTR(-ENOMEM
);
7862 * Single events are their own group leaders, with an
7863 * empty sibling list:
7866 group_leader
= event
;
7868 mutex_init(&event
->child_mutex
);
7869 INIT_LIST_HEAD(&event
->child_list
);
7871 INIT_LIST_HEAD(&event
->group_entry
);
7872 INIT_LIST_HEAD(&event
->event_entry
);
7873 INIT_LIST_HEAD(&event
->sibling_list
);
7874 INIT_LIST_HEAD(&event
->rb_entry
);
7875 INIT_LIST_HEAD(&event
->active_entry
);
7876 INIT_HLIST_NODE(&event
->hlist_entry
);
7879 init_waitqueue_head(&event
->waitq
);
7880 init_irq_work(&event
->pending
, perf_pending_event
);
7882 mutex_init(&event
->mmap_mutex
);
7884 atomic_long_set(&event
->refcount
, 1);
7886 event
->attr
= *attr
;
7887 event
->group_leader
= group_leader
;
7891 event
->parent
= parent_event
;
7893 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7894 event
->id
= atomic64_inc_return(&perf_event_id
);
7896 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7899 event
->attach_state
= PERF_ATTACH_TASK
;
7901 * XXX pmu::event_init needs to know what task to account to
7902 * and we cannot use the ctx information because we need the
7903 * pmu before we get a ctx.
7905 event
->hw
.target
= task
;
7908 event
->clock
= &local_clock
;
7910 event
->clock
= parent_event
->clock
;
7912 if (!overflow_handler
&& parent_event
) {
7913 overflow_handler
= parent_event
->overflow_handler
;
7914 context
= parent_event
->overflow_handler_context
;
7917 event
->overflow_handler
= overflow_handler
;
7918 event
->overflow_handler_context
= context
;
7920 perf_event__state_init(event
);
7925 hwc
->sample_period
= attr
->sample_period
;
7926 if (attr
->freq
&& attr
->sample_freq
)
7927 hwc
->sample_period
= 1;
7928 hwc
->last_period
= hwc
->sample_period
;
7930 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7933 * we currently do not support PERF_FORMAT_GROUP on inherited events
7935 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7938 if (!has_branch_stack(event
))
7939 event
->attr
.branch_sample_type
= 0;
7941 if (cgroup_fd
!= -1) {
7942 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7947 pmu
= perf_init_event(event
);
7950 else if (IS_ERR(pmu
)) {
7955 err
= exclusive_event_init(event
);
7959 if (!event
->parent
) {
7960 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7961 err
= get_callchain_buffers();
7970 exclusive_event_destroy(event
);
7974 event
->destroy(event
);
7975 module_put(pmu
->module
);
7977 if (is_cgroup_event(event
))
7978 perf_detach_cgroup(event
);
7980 put_pid_ns(event
->ns
);
7983 return ERR_PTR(err
);
7986 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7987 struct perf_event_attr
*attr
)
7992 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7996 * zero the full structure, so that a short copy will be nice.
7998 memset(attr
, 0, sizeof(*attr
));
8000 ret
= get_user(size
, &uattr
->size
);
8004 if (size
> PAGE_SIZE
) /* silly large */
8007 if (!size
) /* abi compat */
8008 size
= PERF_ATTR_SIZE_VER0
;
8010 if (size
< PERF_ATTR_SIZE_VER0
)
8014 * If we're handed a bigger struct than we know of,
8015 * ensure all the unknown bits are 0 - i.e. new
8016 * user-space does not rely on any kernel feature
8017 * extensions we dont know about yet.
8019 if (size
> sizeof(*attr
)) {
8020 unsigned char __user
*addr
;
8021 unsigned char __user
*end
;
8024 addr
= (void __user
*)uattr
+ sizeof(*attr
);
8025 end
= (void __user
*)uattr
+ size
;
8027 for (; addr
< end
; addr
++) {
8028 ret
= get_user(val
, addr
);
8034 size
= sizeof(*attr
);
8037 ret
= copy_from_user(attr
, uattr
, size
);
8041 if (attr
->__reserved_1
)
8044 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8047 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8050 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8051 u64 mask
= attr
->branch_sample_type
;
8053 /* only using defined bits */
8054 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8057 /* at least one branch bit must be set */
8058 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8061 /* propagate priv level, when not set for branch */
8062 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8064 /* exclude_kernel checked on syscall entry */
8065 if (!attr
->exclude_kernel
)
8066 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8068 if (!attr
->exclude_user
)
8069 mask
|= PERF_SAMPLE_BRANCH_USER
;
8071 if (!attr
->exclude_hv
)
8072 mask
|= PERF_SAMPLE_BRANCH_HV
;
8074 * adjust user setting (for HW filter setup)
8076 attr
->branch_sample_type
= mask
;
8078 /* privileged levels capture (kernel, hv): check permissions */
8079 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8080 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8084 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8085 ret
= perf_reg_validate(attr
->sample_regs_user
);
8090 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8091 if (!arch_perf_have_user_stack_dump())
8095 * We have __u32 type for the size, but so far
8096 * we can only use __u16 as maximum due to the
8097 * __u16 sample size limit.
8099 if (attr
->sample_stack_user
>= USHRT_MAX
)
8101 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8105 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8106 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8111 put_user(sizeof(*attr
), &uattr
->size
);
8117 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8119 struct ring_buffer
*rb
= NULL
;
8125 /* don't allow circular references */
8126 if (event
== output_event
)
8130 * Don't allow cross-cpu buffers
8132 if (output_event
->cpu
!= event
->cpu
)
8136 * If its not a per-cpu rb, it must be the same task.
8138 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8142 * Mixing clocks in the same buffer is trouble you don't need.
8144 if (output_event
->clock
!= event
->clock
)
8148 * If both events generate aux data, they must be on the same PMU
8150 if (has_aux(event
) && has_aux(output_event
) &&
8151 event
->pmu
!= output_event
->pmu
)
8155 mutex_lock(&event
->mmap_mutex
);
8156 /* Can't redirect output if we've got an active mmap() */
8157 if (atomic_read(&event
->mmap_count
))
8161 /* get the rb we want to redirect to */
8162 rb
= ring_buffer_get(output_event
);
8167 ring_buffer_attach(event
, rb
);
8171 mutex_unlock(&event
->mmap_mutex
);
8177 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8183 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8186 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8188 bool nmi_safe
= false;
8191 case CLOCK_MONOTONIC
:
8192 event
->clock
= &ktime_get_mono_fast_ns
;
8196 case CLOCK_MONOTONIC_RAW
:
8197 event
->clock
= &ktime_get_raw_fast_ns
;
8201 case CLOCK_REALTIME
:
8202 event
->clock
= &ktime_get_real_ns
;
8205 case CLOCK_BOOTTIME
:
8206 event
->clock
= &ktime_get_boot_ns
;
8210 event
->clock
= &ktime_get_tai_ns
;
8217 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8224 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8226 * @attr_uptr: event_id type attributes for monitoring/sampling
8229 * @group_fd: group leader event fd
8231 SYSCALL_DEFINE5(perf_event_open
,
8232 struct perf_event_attr __user
*, attr_uptr
,
8233 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8235 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8236 struct perf_event
*event
, *sibling
;
8237 struct perf_event_attr attr
;
8238 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8239 struct file
*event_file
= NULL
;
8240 struct fd group
= {NULL
, 0};
8241 struct task_struct
*task
= NULL
;
8246 int f_flags
= O_RDWR
;
8249 /* for future expandability... */
8250 if (flags
& ~PERF_FLAG_ALL
)
8253 err
= perf_copy_attr(attr_uptr
, &attr
);
8257 if (!attr
.exclude_kernel
) {
8258 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8263 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8266 if (attr
.sample_period
& (1ULL << 63))
8271 * In cgroup mode, the pid argument is used to pass the fd
8272 * opened to the cgroup directory in cgroupfs. The cpu argument
8273 * designates the cpu on which to monitor threads from that
8276 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8279 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8280 f_flags
|= O_CLOEXEC
;
8282 event_fd
= get_unused_fd_flags(f_flags
);
8286 if (group_fd
!= -1) {
8287 err
= perf_fget_light(group_fd
, &group
);
8290 group_leader
= group
.file
->private_data
;
8291 if (flags
& PERF_FLAG_FD_OUTPUT
)
8292 output_event
= group_leader
;
8293 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8294 group_leader
= NULL
;
8297 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8298 task
= find_lively_task_by_vpid(pid
);
8300 err
= PTR_ERR(task
);
8305 if (task
&& group_leader
&&
8306 group_leader
->attr
.inherit
!= attr
.inherit
) {
8313 if (flags
& PERF_FLAG_PID_CGROUP
)
8316 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8317 NULL
, NULL
, cgroup_fd
);
8318 if (IS_ERR(event
)) {
8319 err
= PTR_ERR(event
);
8323 if (is_sampling_event(event
)) {
8324 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8330 account_event(event
);
8333 * Special case software events and allow them to be part of
8334 * any hardware group.
8338 if (attr
.use_clockid
) {
8339 err
= perf_event_set_clock(event
, attr
.clockid
);
8345 (is_software_event(event
) != is_software_event(group_leader
))) {
8346 if (is_software_event(event
)) {
8348 * If event and group_leader are not both a software
8349 * event, and event is, then group leader is not.
8351 * Allow the addition of software events to !software
8352 * groups, this is safe because software events never
8355 pmu
= group_leader
->pmu
;
8356 } else if (is_software_event(group_leader
) &&
8357 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8359 * In case the group is a pure software group, and we
8360 * try to add a hardware event, move the whole group to
8361 * the hardware context.
8368 * Get the target context (task or percpu):
8370 ctx
= find_get_context(pmu
, task
, event
);
8376 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8382 put_task_struct(task
);
8387 * Look up the group leader (we will attach this event to it):
8393 * Do not allow a recursive hierarchy (this new sibling
8394 * becoming part of another group-sibling):
8396 if (group_leader
->group_leader
!= group_leader
)
8399 /* All events in a group should have the same clock */
8400 if (group_leader
->clock
!= event
->clock
)
8404 * Do not allow to attach to a group in a different
8405 * task or CPU context:
8409 * Make sure we're both on the same task, or both
8412 if (group_leader
->ctx
->task
!= ctx
->task
)
8416 * Make sure we're both events for the same CPU;
8417 * grouping events for different CPUs is broken; since
8418 * you can never concurrently schedule them anyhow.
8420 if (group_leader
->cpu
!= event
->cpu
)
8423 if (group_leader
->ctx
!= ctx
)
8428 * Only a group leader can be exclusive or pinned
8430 if (attr
.exclusive
|| attr
.pinned
)
8435 err
= perf_event_set_output(event
, output_event
);
8440 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8442 if (IS_ERR(event_file
)) {
8443 err
= PTR_ERR(event_file
);
8448 gctx
= group_leader
->ctx
;
8449 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8451 mutex_lock(&ctx
->mutex
);
8454 if (!perf_event_validate_size(event
)) {
8460 * Must be under the same ctx::mutex as perf_install_in_context(),
8461 * because we need to serialize with concurrent event creation.
8463 if (!exclusive_event_installable(event
, ctx
)) {
8464 /* exclusive and group stuff are assumed mutually exclusive */
8465 WARN_ON_ONCE(move_group
);
8471 WARN_ON_ONCE(ctx
->parent_ctx
);
8475 * See perf_event_ctx_lock() for comments on the details
8476 * of swizzling perf_event::ctx.
8478 perf_remove_from_context(group_leader
, false);
8480 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8482 perf_remove_from_context(sibling
, false);
8487 * Wait for everybody to stop referencing the events through
8488 * the old lists, before installing it on new lists.
8493 * Install the group siblings before the group leader.
8495 * Because a group leader will try and install the entire group
8496 * (through the sibling list, which is still in-tact), we can
8497 * end up with siblings installed in the wrong context.
8499 * By installing siblings first we NO-OP because they're not
8500 * reachable through the group lists.
8502 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8504 perf_event__state_init(sibling
);
8505 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8510 * Removing from the context ends up with disabled
8511 * event. What we want here is event in the initial
8512 * startup state, ready to be add into new context.
8514 perf_event__state_init(group_leader
);
8515 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8519 * Now that all events are installed in @ctx, nothing
8520 * references @gctx anymore, so drop the last reference we have
8527 * Precalculate sample_data sizes; do while holding ctx::mutex such
8528 * that we're serialized against further additions and before
8529 * perf_install_in_context() which is the point the event is active and
8530 * can use these values.
8532 perf_event__header_size(event
);
8533 perf_event__id_header_size(event
);
8535 perf_install_in_context(ctx
, event
, event
->cpu
);
8536 perf_unpin_context(ctx
);
8539 mutex_unlock(&gctx
->mutex
);
8540 mutex_unlock(&ctx
->mutex
);
8544 event
->owner
= current
;
8546 mutex_lock(¤t
->perf_event_mutex
);
8547 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8548 mutex_unlock(¤t
->perf_event_mutex
);
8551 * Drop the reference on the group_event after placing the
8552 * new event on the sibling_list. This ensures destruction
8553 * of the group leader will find the pointer to itself in
8554 * perf_group_detach().
8557 fd_install(event_fd
, event_file
);
8562 mutex_unlock(&gctx
->mutex
);
8563 mutex_unlock(&ctx
->mutex
);
8567 perf_unpin_context(ctx
);
8575 put_task_struct(task
);
8579 put_unused_fd(event_fd
);
8584 * perf_event_create_kernel_counter
8586 * @attr: attributes of the counter to create
8587 * @cpu: cpu in which the counter is bound
8588 * @task: task to profile (NULL for percpu)
8591 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8592 struct task_struct
*task
,
8593 perf_overflow_handler_t overflow_handler
,
8596 struct perf_event_context
*ctx
;
8597 struct perf_event
*event
;
8601 * Get the target context (task or percpu):
8604 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8605 overflow_handler
, context
, -1);
8606 if (IS_ERR(event
)) {
8607 err
= PTR_ERR(event
);
8611 /* Mark owner so we could distinguish it from user events. */
8612 event
->owner
= EVENT_OWNER_KERNEL
;
8614 account_event(event
);
8616 ctx
= find_get_context(event
->pmu
, task
, event
);
8622 WARN_ON_ONCE(ctx
->parent_ctx
);
8623 mutex_lock(&ctx
->mutex
);
8624 if (!exclusive_event_installable(event
, ctx
)) {
8625 mutex_unlock(&ctx
->mutex
);
8626 perf_unpin_context(ctx
);
8632 perf_install_in_context(ctx
, event
, cpu
);
8633 perf_unpin_context(ctx
);
8634 mutex_unlock(&ctx
->mutex
);
8641 return ERR_PTR(err
);
8643 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8645 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8647 struct perf_event_context
*src_ctx
;
8648 struct perf_event_context
*dst_ctx
;
8649 struct perf_event
*event
, *tmp
;
8652 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8653 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8656 * See perf_event_ctx_lock() for comments on the details
8657 * of swizzling perf_event::ctx.
8659 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8660 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8662 perf_remove_from_context(event
, false);
8663 unaccount_event_cpu(event
, src_cpu
);
8665 list_add(&event
->migrate_entry
, &events
);
8669 * Wait for the events to quiesce before re-instating them.
8674 * Re-instate events in 2 passes.
8676 * Skip over group leaders and only install siblings on this first
8677 * pass, siblings will not get enabled without a leader, however a
8678 * leader will enable its siblings, even if those are still on the old
8681 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8682 if (event
->group_leader
== event
)
8685 list_del(&event
->migrate_entry
);
8686 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8687 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8688 account_event_cpu(event
, dst_cpu
);
8689 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8694 * Once all the siblings are setup properly, install the group leaders
8697 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8698 list_del(&event
->migrate_entry
);
8699 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8700 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8701 account_event_cpu(event
, dst_cpu
);
8702 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8705 mutex_unlock(&dst_ctx
->mutex
);
8706 mutex_unlock(&src_ctx
->mutex
);
8708 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8710 static void sync_child_event(struct perf_event
*child_event
,
8711 struct task_struct
*child
)
8713 struct perf_event
*parent_event
= child_event
->parent
;
8716 if (child_event
->attr
.inherit_stat
)
8717 perf_event_read_event(child_event
, child
);
8719 child_val
= perf_event_count(child_event
);
8722 * Add back the child's count to the parent's count:
8724 atomic64_add(child_val
, &parent_event
->child_count
);
8725 atomic64_add(child_event
->total_time_enabled
,
8726 &parent_event
->child_total_time_enabled
);
8727 atomic64_add(child_event
->total_time_running
,
8728 &parent_event
->child_total_time_running
);
8731 * Remove this event from the parent's list
8733 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8734 mutex_lock(&parent_event
->child_mutex
);
8735 list_del_init(&child_event
->child_list
);
8736 mutex_unlock(&parent_event
->child_mutex
);
8739 * Make sure user/parent get notified, that we just
8742 perf_event_wakeup(parent_event
);
8745 * Release the parent event, if this was the last
8748 put_event(parent_event
);
8752 __perf_event_exit_task(struct perf_event
*child_event
,
8753 struct perf_event_context
*child_ctx
,
8754 struct task_struct
*child
)
8757 * Do not destroy the 'original' grouping; because of the context
8758 * switch optimization the original events could've ended up in a
8759 * random child task.
8761 * If we were to destroy the original group, all group related
8762 * operations would cease to function properly after this random
8765 * Do destroy all inherited groups, we don't care about those
8766 * and being thorough is better.
8768 perf_remove_from_context(child_event
, !!child_event
->parent
);
8771 * It can happen that the parent exits first, and has events
8772 * that are still around due to the child reference. These
8773 * events need to be zapped.
8775 if (child_event
->parent
) {
8776 sync_child_event(child_event
, child
);
8777 free_event(child_event
);
8779 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8780 perf_event_wakeup(child_event
);
8784 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8786 struct perf_event
*child_event
, *next
;
8787 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8788 unsigned long flags
;
8790 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
8791 perf_event_task(child
, NULL
, 0);
8795 local_irq_save(flags
);
8797 * We can't reschedule here because interrupts are disabled,
8798 * and either child is current or it is a task that can't be
8799 * scheduled, so we are now safe from rescheduling changing
8802 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8805 * Take the context lock here so that if find_get_context is
8806 * reading child->perf_event_ctxp, we wait until it has
8807 * incremented the context's refcount before we do put_ctx below.
8809 raw_spin_lock(&child_ctx
->lock
);
8810 task_ctx_sched_out(child_ctx
);
8811 child
->perf_event_ctxp
[ctxn
] = NULL
;
8814 * If this context is a clone; unclone it so it can't get
8815 * swapped to another process while we're removing all
8816 * the events from it.
8818 clone_ctx
= unclone_ctx(child_ctx
);
8819 update_context_time(child_ctx
);
8820 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8826 * Report the task dead after unscheduling the events so that we
8827 * won't get any samples after PERF_RECORD_EXIT. We can however still
8828 * get a few PERF_RECORD_READ events.
8830 perf_event_task(child
, child_ctx
, 0);
8833 * We can recurse on the same lock type through:
8835 * __perf_event_exit_task()
8836 * sync_child_event()
8838 * mutex_lock(&ctx->mutex)
8840 * But since its the parent context it won't be the same instance.
8842 mutex_lock(&child_ctx
->mutex
);
8844 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8845 __perf_event_exit_task(child_event
, child_ctx
, child
);
8847 mutex_unlock(&child_ctx
->mutex
);
8853 * When a child task exits, feed back event values to parent events.
8855 void perf_event_exit_task(struct task_struct
*child
)
8857 struct perf_event
*event
, *tmp
;
8860 mutex_lock(&child
->perf_event_mutex
);
8861 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8863 list_del_init(&event
->owner_entry
);
8866 * Ensure the list deletion is visible before we clear
8867 * the owner, closes a race against perf_release() where
8868 * we need to serialize on the owner->perf_event_mutex.
8871 event
->owner
= NULL
;
8873 mutex_unlock(&child
->perf_event_mutex
);
8875 for_each_task_context_nr(ctxn
)
8876 perf_event_exit_task_context(child
, ctxn
);
8879 static void perf_free_event(struct perf_event
*event
,
8880 struct perf_event_context
*ctx
)
8882 struct perf_event
*parent
= event
->parent
;
8884 if (WARN_ON_ONCE(!parent
))
8887 mutex_lock(&parent
->child_mutex
);
8888 list_del_init(&event
->child_list
);
8889 mutex_unlock(&parent
->child_mutex
);
8893 raw_spin_lock_irq(&ctx
->lock
);
8894 perf_group_detach(event
);
8895 list_del_event(event
, ctx
);
8896 raw_spin_unlock_irq(&ctx
->lock
);
8901 * Free an unexposed, unused context as created by inheritance by
8902 * perf_event_init_task below, used by fork() in case of fail.
8904 * Not all locks are strictly required, but take them anyway to be nice and
8905 * help out with the lockdep assertions.
8907 void perf_event_free_task(struct task_struct
*task
)
8909 struct perf_event_context
*ctx
;
8910 struct perf_event
*event
, *tmp
;
8913 for_each_task_context_nr(ctxn
) {
8914 ctx
= task
->perf_event_ctxp
[ctxn
];
8918 mutex_lock(&ctx
->mutex
);
8920 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8922 perf_free_event(event
, ctx
);
8924 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8926 perf_free_event(event
, ctx
);
8928 if (!list_empty(&ctx
->pinned_groups
) ||
8929 !list_empty(&ctx
->flexible_groups
))
8932 mutex_unlock(&ctx
->mutex
);
8938 void perf_event_delayed_put(struct task_struct
*task
)
8942 for_each_task_context_nr(ctxn
)
8943 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8946 struct perf_event
*perf_event_get(unsigned int fd
)
8950 struct perf_event
*event
;
8952 err
= perf_fget_light(fd
, &f
);
8954 return ERR_PTR(err
);
8956 event
= f
.file
->private_data
;
8957 atomic_long_inc(&event
->refcount
);
8963 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8966 return ERR_PTR(-EINVAL
);
8968 return &event
->attr
;
8972 * inherit a event from parent task to child task:
8974 static struct perf_event
*
8975 inherit_event(struct perf_event
*parent_event
,
8976 struct task_struct
*parent
,
8977 struct perf_event_context
*parent_ctx
,
8978 struct task_struct
*child
,
8979 struct perf_event
*group_leader
,
8980 struct perf_event_context
*child_ctx
)
8982 enum perf_event_active_state parent_state
= parent_event
->state
;
8983 struct perf_event
*child_event
;
8984 unsigned long flags
;
8987 * Instead of creating recursive hierarchies of events,
8988 * we link inherited events back to the original parent,
8989 * which has a filp for sure, which we use as the reference
8992 if (parent_event
->parent
)
8993 parent_event
= parent_event
->parent
;
8995 child_event
= perf_event_alloc(&parent_event
->attr
,
8998 group_leader
, parent_event
,
9000 if (IS_ERR(child_event
))
9003 if (is_orphaned_event(parent_event
) ||
9004 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
9005 free_event(child_event
);
9012 * Make the child state follow the state of the parent event,
9013 * not its attr.disabled bit. We hold the parent's mutex,
9014 * so we won't race with perf_event_{en, dis}able_family.
9016 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
9017 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
9019 child_event
->state
= PERF_EVENT_STATE_OFF
;
9021 if (parent_event
->attr
.freq
) {
9022 u64 sample_period
= parent_event
->hw
.sample_period
;
9023 struct hw_perf_event
*hwc
= &child_event
->hw
;
9025 hwc
->sample_period
= sample_period
;
9026 hwc
->last_period
= sample_period
;
9028 local64_set(&hwc
->period_left
, sample_period
);
9031 child_event
->ctx
= child_ctx
;
9032 child_event
->overflow_handler
= parent_event
->overflow_handler
;
9033 child_event
->overflow_handler_context
9034 = parent_event
->overflow_handler_context
;
9037 * Precalculate sample_data sizes
9039 perf_event__header_size(child_event
);
9040 perf_event__id_header_size(child_event
);
9043 * Link it up in the child's context:
9045 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9046 add_event_to_ctx(child_event
, child_ctx
);
9047 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9050 * Link this into the parent event's child list
9052 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9053 mutex_lock(&parent_event
->child_mutex
);
9054 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9055 mutex_unlock(&parent_event
->child_mutex
);
9060 static int inherit_group(struct perf_event
*parent_event
,
9061 struct task_struct
*parent
,
9062 struct perf_event_context
*parent_ctx
,
9063 struct task_struct
*child
,
9064 struct perf_event_context
*child_ctx
)
9066 struct perf_event
*leader
;
9067 struct perf_event
*sub
;
9068 struct perf_event
*child_ctr
;
9070 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9071 child
, NULL
, child_ctx
);
9073 return PTR_ERR(leader
);
9074 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9075 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9076 child
, leader
, child_ctx
);
9077 if (IS_ERR(child_ctr
))
9078 return PTR_ERR(child_ctr
);
9084 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9085 struct perf_event_context
*parent_ctx
,
9086 struct task_struct
*child
, int ctxn
,
9090 struct perf_event_context
*child_ctx
;
9092 if (!event
->attr
.inherit
) {
9097 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9100 * This is executed from the parent task context, so
9101 * inherit events that have been marked for cloning.
9102 * First allocate and initialize a context for the
9106 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9110 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9113 ret
= inherit_group(event
, parent
, parent_ctx
,
9123 * Initialize the perf_event context in task_struct
9125 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9127 struct perf_event_context
*child_ctx
, *parent_ctx
;
9128 struct perf_event_context
*cloned_ctx
;
9129 struct perf_event
*event
;
9130 struct task_struct
*parent
= current
;
9131 int inherited_all
= 1;
9132 unsigned long flags
;
9135 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9139 * If the parent's context is a clone, pin it so it won't get
9142 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9147 * No need to check if parent_ctx != NULL here; since we saw
9148 * it non-NULL earlier, the only reason for it to become NULL
9149 * is if we exit, and since we're currently in the middle of
9150 * a fork we can't be exiting at the same time.
9154 * Lock the parent list. No need to lock the child - not PID
9155 * hashed yet and not running, so nobody can access it.
9157 mutex_lock(&parent_ctx
->mutex
);
9160 * We dont have to disable NMIs - we are only looking at
9161 * the list, not manipulating it:
9163 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9164 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9165 child
, ctxn
, &inherited_all
);
9171 * We can't hold ctx->lock when iterating the ->flexible_group list due
9172 * to allocations, but we need to prevent rotation because
9173 * rotate_ctx() will change the list from interrupt context.
9175 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9176 parent_ctx
->rotate_disable
= 1;
9177 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9179 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9180 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9181 child
, ctxn
, &inherited_all
);
9186 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9187 parent_ctx
->rotate_disable
= 0;
9189 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9191 if (child_ctx
&& inherited_all
) {
9193 * Mark the child context as a clone of the parent
9194 * context, or of whatever the parent is a clone of.
9196 * Note that if the parent is a clone, the holding of
9197 * parent_ctx->lock avoids it from being uncloned.
9199 cloned_ctx
= parent_ctx
->parent_ctx
;
9201 child_ctx
->parent_ctx
= cloned_ctx
;
9202 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9204 child_ctx
->parent_ctx
= parent_ctx
;
9205 child_ctx
->parent_gen
= parent_ctx
->generation
;
9207 get_ctx(child_ctx
->parent_ctx
);
9210 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9211 mutex_unlock(&parent_ctx
->mutex
);
9213 perf_unpin_context(parent_ctx
);
9214 put_ctx(parent_ctx
);
9220 * Initialize the perf_event context in task_struct
9222 int perf_event_init_task(struct task_struct
*child
)
9226 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9227 mutex_init(&child
->perf_event_mutex
);
9228 INIT_LIST_HEAD(&child
->perf_event_list
);
9230 for_each_task_context_nr(ctxn
) {
9231 ret
= perf_event_init_context(child
, ctxn
);
9233 perf_event_free_task(child
);
9241 static void __init
perf_event_init_all_cpus(void)
9243 struct swevent_htable
*swhash
;
9246 for_each_possible_cpu(cpu
) {
9247 swhash
= &per_cpu(swevent_htable
, cpu
);
9248 mutex_init(&swhash
->hlist_mutex
);
9249 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9253 static void perf_event_init_cpu(int cpu
)
9255 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9257 mutex_lock(&swhash
->hlist_mutex
);
9258 swhash
->online
= true;
9259 if (swhash
->hlist_refcount
> 0) {
9260 struct swevent_hlist
*hlist
;
9262 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9264 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9266 mutex_unlock(&swhash
->hlist_mutex
);
9269 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9270 static void __perf_event_exit_context(void *__info
)
9272 struct remove_event re
= { .detach_group
= true };
9273 struct perf_event_context
*ctx
= __info
;
9276 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
9277 __perf_remove_from_context(&re
);
9281 static void perf_event_exit_cpu_context(int cpu
)
9283 struct perf_event_context
*ctx
;
9287 idx
= srcu_read_lock(&pmus_srcu
);
9288 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9289 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9291 mutex_lock(&ctx
->mutex
);
9292 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9293 mutex_unlock(&ctx
->mutex
);
9295 srcu_read_unlock(&pmus_srcu
, idx
);
9298 static void perf_event_exit_cpu(int cpu
)
9300 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9302 perf_event_exit_cpu_context(cpu
);
9304 mutex_lock(&swhash
->hlist_mutex
);
9305 swhash
->online
= false;
9306 swevent_hlist_release(swhash
);
9307 mutex_unlock(&swhash
->hlist_mutex
);
9310 static inline void perf_event_exit_cpu(int cpu
) { }
9314 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9318 for_each_online_cpu(cpu
)
9319 perf_event_exit_cpu(cpu
);
9325 * Run the perf reboot notifier at the very last possible moment so that
9326 * the generic watchdog code runs as long as possible.
9328 static struct notifier_block perf_reboot_notifier
= {
9329 .notifier_call
= perf_reboot
,
9330 .priority
= INT_MIN
,
9334 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9336 unsigned int cpu
= (long)hcpu
;
9338 switch (action
& ~CPU_TASKS_FROZEN
) {
9340 case CPU_UP_PREPARE
:
9341 case CPU_DOWN_FAILED
:
9342 perf_event_init_cpu(cpu
);
9345 case CPU_UP_CANCELED
:
9346 case CPU_DOWN_PREPARE
:
9347 perf_event_exit_cpu(cpu
);
9356 void __init
perf_event_init(void)
9362 perf_event_init_all_cpus();
9363 init_srcu_struct(&pmus_srcu
);
9364 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9365 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9366 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9368 perf_cpu_notifier(perf_cpu_notify
);
9369 register_reboot_notifier(&perf_reboot_notifier
);
9371 ret
= init_hw_breakpoint();
9372 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9374 /* do not patch jump label more than once per second */
9375 jump_label_rate_limit(&perf_sched_events
, HZ
);
9378 * Build time assertion that we keep the data_head at the intended
9379 * location. IOW, validation we got the __reserved[] size right.
9381 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9385 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9388 struct perf_pmu_events_attr
*pmu_attr
=
9389 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9391 if (pmu_attr
->event_str
)
9392 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9397 static int __init
perf_event_sysfs_init(void)
9402 mutex_lock(&pmus_lock
);
9404 ret
= bus_register(&pmu_bus
);
9408 list_for_each_entry(pmu
, &pmus
, entry
) {
9409 if (!pmu
->name
|| pmu
->type
< 0)
9412 ret
= pmu_dev_alloc(pmu
);
9413 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9415 pmu_bus_running
= 1;
9419 mutex_unlock(&pmus_lock
);
9423 device_initcall(perf_event_sysfs_init
);
9425 #ifdef CONFIG_CGROUP_PERF
9426 static struct cgroup_subsys_state
*
9427 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9429 struct perf_cgroup
*jc
;
9431 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9433 return ERR_PTR(-ENOMEM
);
9435 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9438 return ERR_PTR(-ENOMEM
);
9444 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9446 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9448 free_percpu(jc
->info
);
9452 static int __perf_cgroup_move(void *info
)
9454 struct task_struct
*task
= info
;
9455 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9459 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
9460 struct cgroup_taskset
*tset
)
9462 struct task_struct
*task
;
9464 cgroup_taskset_for_each(task
, tset
)
9465 task_function_call(task
, __perf_cgroup_move
, task
);
9468 struct cgroup_subsys perf_event_cgrp_subsys
= {
9469 .css_alloc
= perf_cgroup_css_alloc
,
9470 .css_free
= perf_cgroup_css_free
,
9471 .attach
= perf_cgroup_attach
,
9473 #endif /* CONFIG_CGROUP_PERF */