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
;
167 static LIST_HEAD(pmus
);
168 static DEFINE_MUTEX(pmus_lock
);
169 static struct srcu_struct pmus_srcu
;
172 * perf event paranoia level:
173 * -1 - not paranoid at all
174 * 0 - disallow raw tracepoint access for unpriv
175 * 1 - disallow cpu events for unpriv
176 * 2 - disallow kernel profiling for unpriv
178 int sysctl_perf_event_paranoid __read_mostly
= 1;
180 /* Minimum for 512 kiB + 1 user control page */
181 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
184 * max perf event sample rate
186 #define DEFAULT_MAX_SAMPLE_RATE 100000
187 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
188 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
190 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
192 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
193 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
195 static int perf_sample_allowed_ns __read_mostly
=
196 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
198 void update_perf_cpu_limits(void)
200 u64 tmp
= perf_sample_period_ns
;
202 tmp
*= sysctl_perf_cpu_time_max_percent
;
204 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
207 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
209 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
210 void __user
*buffer
, size_t *lenp
,
213 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
218 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
219 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
220 update_perf_cpu_limits();
225 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
227 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
228 void __user
*buffer
, size_t *lenp
,
231 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
236 update_perf_cpu_limits();
242 * perf samples are done in some very critical code paths (NMIs).
243 * If they take too much CPU time, the system can lock up and not
244 * get any real work done. This will drop the sample rate when
245 * we detect that events are taking too long.
247 #define NR_ACCUMULATED_SAMPLES 128
248 static DEFINE_PER_CPU(u64
, running_sample_length
);
250 static void perf_duration_warn(struct irq_work
*w
)
252 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
253 u64 avg_local_sample_len
;
254 u64 local_samples_len
;
256 local_samples_len
= __this_cpu_read(running_sample_length
);
257 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
259 printk_ratelimited(KERN_WARNING
260 "perf interrupt took too long (%lld > %lld), lowering "
261 "kernel.perf_event_max_sample_rate to %d\n",
262 avg_local_sample_len
, allowed_ns
>> 1,
263 sysctl_perf_event_sample_rate
);
266 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
268 void perf_sample_event_took(u64 sample_len_ns
)
270 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
271 u64 avg_local_sample_len
;
272 u64 local_samples_len
;
277 /* decay the counter by 1 average sample */
278 local_samples_len
= __this_cpu_read(running_sample_length
);
279 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
280 local_samples_len
+= sample_len_ns
;
281 __this_cpu_write(running_sample_length
, local_samples_len
);
284 * note: this will be biased artifically low until we have
285 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
286 * from having to maintain a count.
288 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
290 if (avg_local_sample_len
<= allowed_ns
)
293 if (max_samples_per_tick
<= 1)
296 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
297 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
298 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
300 update_perf_cpu_limits();
302 if (!irq_work_queue(&perf_duration_work
)) {
303 early_printk("perf interrupt took too long (%lld > %lld), lowering "
304 "kernel.perf_event_max_sample_rate to %d\n",
305 avg_local_sample_len
, allowed_ns
>> 1,
306 sysctl_perf_event_sample_rate
);
310 static atomic64_t perf_event_id
;
312 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
313 enum event_type_t event_type
);
315 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
316 enum event_type_t event_type
,
317 struct task_struct
*task
);
319 static void update_context_time(struct perf_event_context
*ctx
);
320 static u64
perf_event_time(struct perf_event
*event
);
322 void __weak
perf_event_print_debug(void) { }
324 extern __weak
const char *perf_pmu_name(void)
329 static inline u64
perf_clock(void)
331 return local_clock();
334 static inline u64
perf_event_clock(struct perf_event
*event
)
336 return event
->clock();
339 static inline struct perf_cpu_context
*
340 __get_cpu_context(struct perf_event_context
*ctx
)
342 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
345 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
346 struct perf_event_context
*ctx
)
348 raw_spin_lock(&cpuctx
->ctx
.lock
);
350 raw_spin_lock(&ctx
->lock
);
353 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
354 struct perf_event_context
*ctx
)
357 raw_spin_unlock(&ctx
->lock
);
358 raw_spin_unlock(&cpuctx
->ctx
.lock
);
361 #ifdef CONFIG_CGROUP_PERF
364 perf_cgroup_match(struct perf_event
*event
)
366 struct perf_event_context
*ctx
= event
->ctx
;
367 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
369 /* @event doesn't care about cgroup */
373 /* wants specific cgroup scope but @cpuctx isn't associated with any */
378 * Cgroup scoping is recursive. An event enabled for a cgroup is
379 * also enabled for all its descendant cgroups. If @cpuctx's
380 * cgroup is a descendant of @event's (the test covers identity
381 * case), it's a match.
383 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
384 event
->cgrp
->css
.cgroup
);
387 static inline void perf_detach_cgroup(struct perf_event
*event
)
389 css_put(&event
->cgrp
->css
);
393 static inline int is_cgroup_event(struct perf_event
*event
)
395 return event
->cgrp
!= NULL
;
398 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
400 struct perf_cgroup_info
*t
;
402 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
406 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
408 struct perf_cgroup_info
*info
;
413 info
= this_cpu_ptr(cgrp
->info
);
415 info
->time
+= now
- info
->timestamp
;
416 info
->timestamp
= now
;
419 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
421 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
423 __update_cgrp_time(cgrp_out
);
426 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
428 struct perf_cgroup
*cgrp
;
431 * ensure we access cgroup data only when needed and
432 * when we know the cgroup is pinned (css_get)
434 if (!is_cgroup_event(event
))
437 cgrp
= perf_cgroup_from_task(current
);
439 * Do not update time when cgroup is not active
441 if (cgrp
== event
->cgrp
)
442 __update_cgrp_time(event
->cgrp
);
446 perf_cgroup_set_timestamp(struct task_struct
*task
,
447 struct perf_event_context
*ctx
)
449 struct perf_cgroup
*cgrp
;
450 struct perf_cgroup_info
*info
;
453 * ctx->lock held by caller
454 * ensure we do not access cgroup data
455 * unless we have the cgroup pinned (css_get)
457 if (!task
|| !ctx
->nr_cgroups
)
460 cgrp
= perf_cgroup_from_task(task
);
461 info
= this_cpu_ptr(cgrp
->info
);
462 info
->timestamp
= ctx
->timestamp
;
465 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
466 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
469 * reschedule events based on the cgroup constraint of task.
471 * mode SWOUT : schedule out everything
472 * mode SWIN : schedule in based on cgroup for next
474 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
476 struct perf_cpu_context
*cpuctx
;
481 * disable interrupts to avoid geting nr_cgroup
482 * changes via __perf_event_disable(). Also
485 local_irq_save(flags
);
488 * we reschedule only in the presence of cgroup
489 * constrained events.
493 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
494 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
495 if (cpuctx
->unique_pmu
!= pmu
)
496 continue; /* ensure we process each cpuctx once */
499 * perf_cgroup_events says at least one
500 * context on this CPU has cgroup events.
502 * ctx->nr_cgroups reports the number of cgroup
503 * events for a context.
505 if (cpuctx
->ctx
.nr_cgroups
> 0) {
506 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
507 perf_pmu_disable(cpuctx
->ctx
.pmu
);
509 if (mode
& PERF_CGROUP_SWOUT
) {
510 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
512 * must not be done before ctxswout due
513 * to event_filter_match() in event_sched_out()
518 if (mode
& PERF_CGROUP_SWIN
) {
519 WARN_ON_ONCE(cpuctx
->cgrp
);
521 * set cgrp before ctxsw in to allow
522 * event_filter_match() to not have to pass
525 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
526 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
528 perf_pmu_enable(cpuctx
->ctx
.pmu
);
529 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
535 local_irq_restore(flags
);
538 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
539 struct task_struct
*next
)
541 struct perf_cgroup
*cgrp1
;
542 struct perf_cgroup
*cgrp2
= NULL
;
545 * we come here when we know perf_cgroup_events > 0
547 cgrp1
= perf_cgroup_from_task(task
);
550 * next is NULL when called from perf_event_enable_on_exec()
551 * that will systematically cause a cgroup_switch()
554 cgrp2
= perf_cgroup_from_task(next
);
557 * only schedule out current cgroup events if we know
558 * that we are switching to a different cgroup. Otherwise,
559 * do no touch the cgroup events.
562 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
565 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
566 struct task_struct
*task
)
568 struct perf_cgroup
*cgrp1
;
569 struct perf_cgroup
*cgrp2
= NULL
;
572 * we come here when we know perf_cgroup_events > 0
574 cgrp1
= perf_cgroup_from_task(task
);
576 /* prev can never be NULL */
577 cgrp2
= perf_cgroup_from_task(prev
);
580 * only need to schedule in cgroup events if we are changing
581 * cgroup during ctxsw. Cgroup events were not scheduled
582 * out of ctxsw out if that was not the case.
585 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
588 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
589 struct perf_event_attr
*attr
,
590 struct perf_event
*group_leader
)
592 struct perf_cgroup
*cgrp
;
593 struct cgroup_subsys_state
*css
;
594 struct fd f
= fdget(fd
);
600 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
601 &perf_event_cgrp_subsys
);
607 cgrp
= container_of(css
, struct perf_cgroup
, css
);
611 * all events in a group must monitor
612 * the same cgroup because a task belongs
613 * to only one perf cgroup at a time
615 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
616 perf_detach_cgroup(event
);
625 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
627 struct perf_cgroup_info
*t
;
628 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
629 event
->shadow_ctx_time
= now
- t
->timestamp
;
633 perf_cgroup_defer_enabled(struct perf_event
*event
)
636 * when the current task's perf cgroup does not match
637 * the event's, we need to remember to call the
638 * perf_mark_enable() function the first time a task with
639 * a matching perf cgroup is scheduled in.
641 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
642 event
->cgrp_defer_enabled
= 1;
646 perf_cgroup_mark_enabled(struct perf_event
*event
,
647 struct perf_event_context
*ctx
)
649 struct perf_event
*sub
;
650 u64 tstamp
= perf_event_time(event
);
652 if (!event
->cgrp_defer_enabled
)
655 event
->cgrp_defer_enabled
= 0;
657 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
658 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
659 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
660 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
661 sub
->cgrp_defer_enabled
= 0;
665 #else /* !CONFIG_CGROUP_PERF */
668 perf_cgroup_match(struct perf_event
*event
)
673 static inline void perf_detach_cgroup(struct perf_event
*event
)
676 static inline int is_cgroup_event(struct perf_event
*event
)
681 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
686 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
690 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
694 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
695 struct task_struct
*next
)
699 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
700 struct task_struct
*task
)
704 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
705 struct perf_event_attr
*attr
,
706 struct perf_event
*group_leader
)
712 perf_cgroup_set_timestamp(struct task_struct
*task
,
713 struct perf_event_context
*ctx
)
718 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
723 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
727 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
733 perf_cgroup_defer_enabled(struct perf_event
*event
)
738 perf_cgroup_mark_enabled(struct perf_event
*event
,
739 struct perf_event_context
*ctx
)
745 * set default to be dependent on timer tick just
748 #define PERF_CPU_HRTIMER (1000 / HZ)
750 * function must be called with interrupts disbled
752 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
754 struct perf_cpu_context
*cpuctx
;
757 WARN_ON(!irqs_disabled());
759 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
760 rotations
= perf_rotate_context(cpuctx
);
762 raw_spin_lock(&cpuctx
->hrtimer_lock
);
764 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
766 cpuctx
->hrtimer_active
= 0;
767 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
769 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
772 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
774 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
775 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
778 /* no multiplexing needed for SW PMU */
779 if (pmu
->task_ctx_nr
== perf_sw_context
)
783 * check default is sane, if not set then force to
784 * default interval (1/tick)
786 interval
= pmu
->hrtimer_interval_ms
;
788 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
790 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
792 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
793 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
794 timer
->function
= perf_mux_hrtimer_handler
;
797 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
799 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
800 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
804 if (pmu
->task_ctx_nr
== perf_sw_context
)
807 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
808 if (!cpuctx
->hrtimer_active
) {
809 cpuctx
->hrtimer_active
= 1;
810 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
811 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
813 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
818 void perf_pmu_disable(struct pmu
*pmu
)
820 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
822 pmu
->pmu_disable(pmu
);
825 void perf_pmu_enable(struct pmu
*pmu
)
827 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
829 pmu
->pmu_enable(pmu
);
832 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
835 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
836 * perf_event_task_tick() are fully serialized because they're strictly cpu
837 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
838 * disabled, while perf_event_task_tick is called from IRQ context.
840 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
842 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
844 WARN_ON(!irqs_disabled());
846 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
848 list_add(&ctx
->active_ctx_list
, head
);
851 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
853 WARN_ON(!irqs_disabled());
855 WARN_ON(list_empty(&ctx
->active_ctx_list
));
857 list_del_init(&ctx
->active_ctx_list
);
860 static void get_ctx(struct perf_event_context
*ctx
)
862 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
865 static void free_ctx(struct rcu_head
*head
)
867 struct perf_event_context
*ctx
;
869 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
870 kfree(ctx
->task_ctx_data
);
874 static void put_ctx(struct perf_event_context
*ctx
)
876 if (atomic_dec_and_test(&ctx
->refcount
)) {
878 put_ctx(ctx
->parent_ctx
);
880 put_task_struct(ctx
->task
);
881 call_rcu(&ctx
->rcu_head
, free_ctx
);
886 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
887 * perf_pmu_migrate_context() we need some magic.
889 * Those places that change perf_event::ctx will hold both
890 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
892 * Lock ordering is by mutex address. There are two other sites where
893 * perf_event_context::mutex nests and those are:
895 * - perf_event_exit_task_context() [ child , 0 ]
896 * __perf_event_exit_task()
898 * put_event() [ parent, 1 ]
900 * - perf_event_init_context() [ parent, 0 ]
901 * inherit_task_group()
906 * perf_try_init_event() [ child , 1 ]
908 * While it appears there is an obvious deadlock here -- the parent and child
909 * nesting levels are inverted between the two. This is in fact safe because
910 * life-time rules separate them. That is an exiting task cannot fork, and a
911 * spawning task cannot (yet) exit.
913 * But remember that that these are parent<->child context relations, and
914 * migration does not affect children, therefore these two orderings should not
917 * The change in perf_event::ctx does not affect children (as claimed above)
918 * because the sys_perf_event_open() case will install a new event and break
919 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
920 * concerned with cpuctx and that doesn't have children.
922 * The places that change perf_event::ctx will issue:
924 * perf_remove_from_context();
926 * perf_install_in_context();
928 * to affect the change. The remove_from_context() + synchronize_rcu() should
929 * quiesce the event, after which we can install it in the new location. This
930 * means that only external vectors (perf_fops, prctl) can perturb the event
931 * while in transit. Therefore all such accessors should also acquire
932 * perf_event_context::mutex to serialize against this.
934 * However; because event->ctx can change while we're waiting to acquire
935 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
939 * task_struct::perf_event_mutex
940 * perf_event_context::mutex
941 * perf_event_context::lock
942 * perf_event::child_mutex;
943 * perf_event::mmap_mutex
946 static struct perf_event_context
*
947 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
949 struct perf_event_context
*ctx
;
953 ctx
= ACCESS_ONCE(event
->ctx
);
954 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
960 mutex_lock_nested(&ctx
->mutex
, nesting
);
961 if (event
->ctx
!= ctx
) {
962 mutex_unlock(&ctx
->mutex
);
970 static inline struct perf_event_context
*
971 perf_event_ctx_lock(struct perf_event
*event
)
973 return perf_event_ctx_lock_nested(event
, 0);
976 static void perf_event_ctx_unlock(struct perf_event
*event
,
977 struct perf_event_context
*ctx
)
979 mutex_unlock(&ctx
->mutex
);
984 * This must be done under the ctx->lock, such as to serialize against
985 * context_equiv(), therefore we cannot call put_ctx() since that might end up
986 * calling scheduler related locks and ctx->lock nests inside those.
988 static __must_check
struct perf_event_context
*
989 unclone_ctx(struct perf_event_context
*ctx
)
991 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
993 lockdep_assert_held(&ctx
->lock
);
996 ctx
->parent_ctx
= NULL
;
1002 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1005 * only top level events have the pid namespace they were created in
1008 event
= event
->parent
;
1010 return task_tgid_nr_ns(p
, event
->ns
);
1013 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1016 * only top level events have the pid namespace they were created in
1019 event
= event
->parent
;
1021 return task_pid_nr_ns(p
, event
->ns
);
1025 * If we inherit events we want to return the parent event id
1028 static u64
primary_event_id(struct perf_event
*event
)
1033 id
= event
->parent
->id
;
1039 * Get the perf_event_context for a task and lock it.
1040 * This has to cope with with the fact that until it is locked,
1041 * the context could get moved to another task.
1043 static struct perf_event_context
*
1044 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1046 struct perf_event_context
*ctx
;
1050 * One of the few rules of preemptible RCU is that one cannot do
1051 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1052 * part of the read side critical section was preemptible -- see
1053 * rcu_read_unlock_special().
1055 * Since ctx->lock nests under rq->lock we must ensure the entire read
1056 * side critical section is non-preemptible.
1060 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1063 * If this context is a clone of another, it might
1064 * get swapped for another underneath us by
1065 * perf_event_task_sched_out, though the
1066 * rcu_read_lock() protects us from any context
1067 * getting freed. Lock the context and check if it
1068 * got swapped before we could get the lock, and retry
1069 * if so. If we locked the right context, then it
1070 * can't get swapped on us any more.
1072 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
1073 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1074 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
1080 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1081 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
1091 * Get the context for a task and increment its pin_count so it
1092 * can't get swapped to another task. This also increments its
1093 * reference count so that the context can't get freed.
1095 static struct perf_event_context
*
1096 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1098 struct perf_event_context
*ctx
;
1099 unsigned long flags
;
1101 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1104 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1109 static void perf_unpin_context(struct perf_event_context
*ctx
)
1111 unsigned long flags
;
1113 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1115 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1119 * Update the record of the current time in a context.
1121 static void update_context_time(struct perf_event_context
*ctx
)
1123 u64 now
= perf_clock();
1125 ctx
->time
+= now
- ctx
->timestamp
;
1126 ctx
->timestamp
= now
;
1129 static u64
perf_event_time(struct perf_event
*event
)
1131 struct perf_event_context
*ctx
= event
->ctx
;
1133 if (is_cgroup_event(event
))
1134 return perf_cgroup_event_time(event
);
1136 return ctx
? ctx
->time
: 0;
1140 * Update the total_time_enabled and total_time_running fields for a event.
1141 * The caller of this function needs to hold the ctx->lock.
1143 static void update_event_times(struct perf_event
*event
)
1145 struct perf_event_context
*ctx
= event
->ctx
;
1148 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1149 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1152 * in cgroup mode, time_enabled represents
1153 * the time the event was enabled AND active
1154 * tasks were in the monitored cgroup. This is
1155 * independent of the activity of the context as
1156 * there may be a mix of cgroup and non-cgroup events.
1158 * That is why we treat cgroup events differently
1161 if (is_cgroup_event(event
))
1162 run_end
= perf_cgroup_event_time(event
);
1163 else if (ctx
->is_active
)
1164 run_end
= ctx
->time
;
1166 run_end
= event
->tstamp_stopped
;
1168 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1170 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1171 run_end
= event
->tstamp_stopped
;
1173 run_end
= perf_event_time(event
);
1175 event
->total_time_running
= run_end
- event
->tstamp_running
;
1180 * Update total_time_enabled and total_time_running for all events in a group.
1182 static void update_group_times(struct perf_event
*leader
)
1184 struct perf_event
*event
;
1186 update_event_times(leader
);
1187 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1188 update_event_times(event
);
1191 static struct list_head
*
1192 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1194 if (event
->attr
.pinned
)
1195 return &ctx
->pinned_groups
;
1197 return &ctx
->flexible_groups
;
1201 * Add a event from the lists for its context.
1202 * Must be called with ctx->mutex and ctx->lock held.
1205 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1207 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1208 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1211 * If we're a stand alone event or group leader, we go to the context
1212 * list, group events are kept attached to the group so that
1213 * perf_group_detach can, at all times, locate all siblings.
1215 if (event
->group_leader
== event
) {
1216 struct list_head
*list
;
1218 if (is_software_event(event
))
1219 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1221 list
= ctx_group_list(event
, ctx
);
1222 list_add_tail(&event
->group_entry
, list
);
1225 if (is_cgroup_event(event
))
1228 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1230 if (event
->attr
.inherit_stat
)
1237 * Initialize event state based on the perf_event_attr::disabled.
1239 static inline void perf_event__state_init(struct perf_event
*event
)
1241 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1242 PERF_EVENT_STATE_INACTIVE
;
1246 * Called at perf_event creation and when events are attached/detached from a
1249 static void perf_event__read_size(struct perf_event
*event
)
1251 int entry
= sizeof(u64
); /* value */
1255 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1256 size
+= sizeof(u64
);
1258 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1259 size
+= sizeof(u64
);
1261 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1262 entry
+= sizeof(u64
);
1264 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1265 nr
+= event
->group_leader
->nr_siblings
;
1266 size
+= sizeof(u64
);
1270 event
->read_size
= size
;
1273 static void perf_event__header_size(struct perf_event
*event
)
1275 struct perf_sample_data
*data
;
1276 u64 sample_type
= event
->attr
.sample_type
;
1279 perf_event__read_size(event
);
1281 if (sample_type
& PERF_SAMPLE_IP
)
1282 size
+= sizeof(data
->ip
);
1284 if (sample_type
& PERF_SAMPLE_ADDR
)
1285 size
+= sizeof(data
->addr
);
1287 if (sample_type
& PERF_SAMPLE_PERIOD
)
1288 size
+= sizeof(data
->period
);
1290 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1291 size
+= sizeof(data
->weight
);
1293 if (sample_type
& PERF_SAMPLE_READ
)
1294 size
+= event
->read_size
;
1296 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1297 size
+= sizeof(data
->data_src
.val
);
1299 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1300 size
+= sizeof(data
->txn
);
1302 event
->header_size
= size
;
1305 static void perf_event__id_header_size(struct perf_event
*event
)
1307 struct perf_sample_data
*data
;
1308 u64 sample_type
= event
->attr
.sample_type
;
1311 if (sample_type
& PERF_SAMPLE_TID
)
1312 size
+= sizeof(data
->tid_entry
);
1314 if (sample_type
& PERF_SAMPLE_TIME
)
1315 size
+= sizeof(data
->time
);
1317 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1318 size
+= sizeof(data
->id
);
1320 if (sample_type
& PERF_SAMPLE_ID
)
1321 size
+= sizeof(data
->id
);
1323 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1324 size
+= sizeof(data
->stream_id
);
1326 if (sample_type
& PERF_SAMPLE_CPU
)
1327 size
+= sizeof(data
->cpu_entry
);
1329 event
->id_header_size
= size
;
1332 static void perf_group_attach(struct perf_event
*event
)
1334 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1337 * We can have double attach due to group movement in perf_event_open.
1339 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1342 event
->attach_state
|= PERF_ATTACH_GROUP
;
1344 if (group_leader
== event
)
1347 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1349 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1350 !is_software_event(event
))
1351 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1353 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1354 group_leader
->nr_siblings
++;
1356 perf_event__header_size(group_leader
);
1358 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1359 perf_event__header_size(pos
);
1363 * Remove a event from the lists for its context.
1364 * Must be called with ctx->mutex and ctx->lock held.
1367 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1369 struct perf_cpu_context
*cpuctx
;
1371 WARN_ON_ONCE(event
->ctx
!= ctx
);
1372 lockdep_assert_held(&ctx
->lock
);
1375 * We can have double detach due to exit/hot-unplug + close.
1377 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1380 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1382 if (is_cgroup_event(event
)) {
1384 cpuctx
= __get_cpu_context(ctx
);
1386 * if there are no more cgroup events
1387 * then cler cgrp to avoid stale pointer
1388 * in update_cgrp_time_from_cpuctx()
1390 if (!ctx
->nr_cgroups
)
1391 cpuctx
->cgrp
= NULL
;
1395 if (event
->attr
.inherit_stat
)
1398 list_del_rcu(&event
->event_entry
);
1400 if (event
->group_leader
== event
)
1401 list_del_init(&event
->group_entry
);
1403 update_group_times(event
);
1406 * If event was in error state, then keep it
1407 * that way, otherwise bogus counts will be
1408 * returned on read(). The only way to get out
1409 * of error state is by explicit re-enabling
1412 if (event
->state
> PERF_EVENT_STATE_OFF
)
1413 event
->state
= PERF_EVENT_STATE_OFF
;
1418 static void perf_group_detach(struct perf_event
*event
)
1420 struct perf_event
*sibling
, *tmp
;
1421 struct list_head
*list
= NULL
;
1424 * We can have double detach due to exit/hot-unplug + close.
1426 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1429 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1432 * If this is a sibling, remove it from its group.
1434 if (event
->group_leader
!= event
) {
1435 list_del_init(&event
->group_entry
);
1436 event
->group_leader
->nr_siblings
--;
1440 if (!list_empty(&event
->group_entry
))
1441 list
= &event
->group_entry
;
1444 * If this was a group event with sibling events then
1445 * upgrade the siblings to singleton events by adding them
1446 * to whatever list we are on.
1448 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1450 list_move_tail(&sibling
->group_entry
, list
);
1451 sibling
->group_leader
= sibling
;
1453 /* Inherit group flags from the previous leader */
1454 sibling
->group_flags
= event
->group_flags
;
1456 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1460 perf_event__header_size(event
->group_leader
);
1462 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1463 perf_event__header_size(tmp
);
1467 * User event without the task.
1469 static bool is_orphaned_event(struct perf_event
*event
)
1471 return event
&& !is_kernel_event(event
) && !event
->owner
;
1475 * Event has a parent but parent's task finished and it's
1476 * alive only because of children holding refference.
1478 static bool is_orphaned_child(struct perf_event
*event
)
1480 return is_orphaned_event(event
->parent
);
1483 static void orphans_remove_work(struct work_struct
*work
);
1485 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1487 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1490 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1492 ctx
->orphans_remove_sched
= true;
1496 static int __init
perf_workqueue_init(void)
1498 perf_wq
= create_singlethread_workqueue("perf");
1499 WARN(!perf_wq
, "failed to create perf workqueue\n");
1500 return perf_wq
? 0 : -1;
1503 core_initcall(perf_workqueue_init
);
1505 static inline int pmu_filter_match(struct perf_event
*event
)
1507 struct pmu
*pmu
= event
->pmu
;
1508 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1512 event_filter_match(struct perf_event
*event
)
1514 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1515 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1519 event_sched_out(struct perf_event
*event
,
1520 struct perf_cpu_context
*cpuctx
,
1521 struct perf_event_context
*ctx
)
1523 u64 tstamp
= perf_event_time(event
);
1526 WARN_ON_ONCE(event
->ctx
!= ctx
);
1527 lockdep_assert_held(&ctx
->lock
);
1530 * An event which could not be activated because of
1531 * filter mismatch still needs to have its timings
1532 * maintained, otherwise bogus information is return
1533 * via read() for time_enabled, time_running:
1535 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1536 && !event_filter_match(event
)) {
1537 delta
= tstamp
- event
->tstamp_stopped
;
1538 event
->tstamp_running
+= delta
;
1539 event
->tstamp_stopped
= tstamp
;
1542 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1545 perf_pmu_disable(event
->pmu
);
1547 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1548 if (event
->pending_disable
) {
1549 event
->pending_disable
= 0;
1550 event
->state
= PERF_EVENT_STATE_OFF
;
1552 event
->tstamp_stopped
= tstamp
;
1553 event
->pmu
->del(event
, 0);
1556 if (!is_software_event(event
))
1557 cpuctx
->active_oncpu
--;
1558 if (!--ctx
->nr_active
)
1559 perf_event_ctx_deactivate(ctx
);
1560 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1562 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1563 cpuctx
->exclusive
= 0;
1565 if (is_orphaned_child(event
))
1566 schedule_orphans_remove(ctx
);
1568 perf_pmu_enable(event
->pmu
);
1572 group_sched_out(struct perf_event
*group_event
,
1573 struct perf_cpu_context
*cpuctx
,
1574 struct perf_event_context
*ctx
)
1576 struct perf_event
*event
;
1577 int state
= group_event
->state
;
1579 event_sched_out(group_event
, cpuctx
, ctx
);
1582 * Schedule out siblings (if any):
1584 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1585 event_sched_out(event
, cpuctx
, ctx
);
1587 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1588 cpuctx
->exclusive
= 0;
1591 struct remove_event
{
1592 struct perf_event
*event
;
1597 * Cross CPU call to remove a performance event
1599 * We disable the event on the hardware level first. After that we
1600 * remove it from the context list.
1602 static int __perf_remove_from_context(void *info
)
1604 struct remove_event
*re
= info
;
1605 struct perf_event
*event
= re
->event
;
1606 struct perf_event_context
*ctx
= event
->ctx
;
1607 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1609 raw_spin_lock(&ctx
->lock
);
1610 event_sched_out(event
, cpuctx
, ctx
);
1611 if (re
->detach_group
)
1612 perf_group_detach(event
);
1613 list_del_event(event
, ctx
);
1614 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1616 cpuctx
->task_ctx
= NULL
;
1618 raw_spin_unlock(&ctx
->lock
);
1625 * Remove the event from a task's (or a CPU's) list of events.
1627 * CPU events are removed with a smp call. For task events we only
1628 * call when the task is on a CPU.
1630 * If event->ctx is a cloned context, callers must make sure that
1631 * every task struct that event->ctx->task could possibly point to
1632 * remains valid. This is OK when called from perf_release since
1633 * that only calls us on the top-level context, which can't be a clone.
1634 * When called from perf_event_exit_task, it's OK because the
1635 * context has been detached from its task.
1637 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1639 struct perf_event_context
*ctx
= event
->ctx
;
1640 struct task_struct
*task
= ctx
->task
;
1641 struct remove_event re
= {
1643 .detach_group
= detach_group
,
1646 lockdep_assert_held(&ctx
->mutex
);
1650 * Per cpu events are removed via an smp call. The removal can
1651 * fail if the CPU is currently offline, but in that case we
1652 * already called __perf_remove_from_context from
1653 * perf_event_exit_cpu.
1655 cpu_function_call(event
->cpu
, __perf_remove_from_context
, &re
);
1660 if (!task_function_call(task
, __perf_remove_from_context
, &re
))
1663 raw_spin_lock_irq(&ctx
->lock
);
1665 * If we failed to find a running task, but find the context active now
1666 * that we've acquired the ctx->lock, retry.
1668 if (ctx
->is_active
) {
1669 raw_spin_unlock_irq(&ctx
->lock
);
1671 * Reload the task pointer, it might have been changed by
1672 * a concurrent perf_event_context_sched_out().
1679 * Since the task isn't running, its safe to remove the event, us
1680 * holding the ctx->lock ensures the task won't get scheduled in.
1683 perf_group_detach(event
);
1684 list_del_event(event
, ctx
);
1685 raw_spin_unlock_irq(&ctx
->lock
);
1689 * Cross CPU call to disable a performance event
1691 int __perf_event_disable(void *info
)
1693 struct perf_event
*event
= info
;
1694 struct perf_event_context
*ctx
= event
->ctx
;
1695 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1698 * If this is a per-task event, need to check whether this
1699 * event's task is the current task on this cpu.
1701 * Can trigger due to concurrent perf_event_context_sched_out()
1702 * flipping contexts around.
1704 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1707 raw_spin_lock(&ctx
->lock
);
1710 * If the event is on, turn it off.
1711 * If it is in error state, leave it in error state.
1713 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1714 update_context_time(ctx
);
1715 update_cgrp_time_from_event(event
);
1716 update_group_times(event
);
1717 if (event
== event
->group_leader
)
1718 group_sched_out(event
, cpuctx
, ctx
);
1720 event_sched_out(event
, cpuctx
, ctx
);
1721 event
->state
= PERF_EVENT_STATE_OFF
;
1724 raw_spin_unlock(&ctx
->lock
);
1732 * If event->ctx is a cloned context, callers must make sure that
1733 * every task struct that event->ctx->task could possibly point to
1734 * remains valid. This condition is satisifed when called through
1735 * perf_event_for_each_child or perf_event_for_each because they
1736 * hold the top-level event's child_mutex, so any descendant that
1737 * goes to exit will block in sync_child_event.
1738 * When called from perf_pending_event it's OK because event->ctx
1739 * is the current context on this CPU and preemption is disabled,
1740 * hence we can't get into perf_event_task_sched_out for this context.
1742 static void _perf_event_disable(struct perf_event
*event
)
1744 struct perf_event_context
*ctx
= event
->ctx
;
1745 struct task_struct
*task
= ctx
->task
;
1749 * Disable the event on the cpu that it's on
1751 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1756 if (!task_function_call(task
, __perf_event_disable
, event
))
1759 raw_spin_lock_irq(&ctx
->lock
);
1761 * If the event is still active, we need to retry the cross-call.
1763 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1764 raw_spin_unlock_irq(&ctx
->lock
);
1766 * Reload the task pointer, it might have been changed by
1767 * a concurrent perf_event_context_sched_out().
1774 * Since we have the lock this context can't be scheduled
1775 * in, so we can change the state safely.
1777 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1778 update_group_times(event
);
1779 event
->state
= PERF_EVENT_STATE_OFF
;
1781 raw_spin_unlock_irq(&ctx
->lock
);
1785 * Strictly speaking kernel users cannot create groups and therefore this
1786 * interface does not need the perf_event_ctx_lock() magic.
1788 void perf_event_disable(struct perf_event
*event
)
1790 struct perf_event_context
*ctx
;
1792 ctx
= perf_event_ctx_lock(event
);
1793 _perf_event_disable(event
);
1794 perf_event_ctx_unlock(event
, ctx
);
1796 EXPORT_SYMBOL_GPL(perf_event_disable
);
1798 static void perf_set_shadow_time(struct perf_event
*event
,
1799 struct perf_event_context
*ctx
,
1803 * use the correct time source for the time snapshot
1805 * We could get by without this by leveraging the
1806 * fact that to get to this function, the caller
1807 * has most likely already called update_context_time()
1808 * and update_cgrp_time_xx() and thus both timestamp
1809 * are identical (or very close). Given that tstamp is,
1810 * already adjusted for cgroup, we could say that:
1811 * tstamp - ctx->timestamp
1813 * tstamp - cgrp->timestamp.
1815 * Then, in perf_output_read(), the calculation would
1816 * work with no changes because:
1817 * - event is guaranteed scheduled in
1818 * - no scheduled out in between
1819 * - thus the timestamp would be the same
1821 * But this is a bit hairy.
1823 * So instead, we have an explicit cgroup call to remain
1824 * within the time time source all along. We believe it
1825 * is cleaner and simpler to understand.
1827 if (is_cgroup_event(event
))
1828 perf_cgroup_set_shadow_time(event
, tstamp
);
1830 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1833 #define MAX_INTERRUPTS (~0ULL)
1835 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1836 static void perf_log_itrace_start(struct perf_event
*event
);
1839 event_sched_in(struct perf_event
*event
,
1840 struct perf_cpu_context
*cpuctx
,
1841 struct perf_event_context
*ctx
)
1843 u64 tstamp
= perf_event_time(event
);
1846 lockdep_assert_held(&ctx
->lock
);
1848 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1851 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1852 event
->oncpu
= smp_processor_id();
1855 * Unthrottle events, since we scheduled we might have missed several
1856 * ticks already, also for a heavily scheduling task there is little
1857 * guarantee it'll get a tick in a timely manner.
1859 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1860 perf_log_throttle(event
, 1);
1861 event
->hw
.interrupts
= 0;
1865 * The new state must be visible before we turn it on in the hardware:
1869 perf_pmu_disable(event
->pmu
);
1871 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1873 perf_set_shadow_time(event
, ctx
, tstamp
);
1875 perf_log_itrace_start(event
);
1877 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1878 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1884 if (!is_software_event(event
))
1885 cpuctx
->active_oncpu
++;
1886 if (!ctx
->nr_active
++)
1887 perf_event_ctx_activate(ctx
);
1888 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1891 if (event
->attr
.exclusive
)
1892 cpuctx
->exclusive
= 1;
1894 if (is_orphaned_child(event
))
1895 schedule_orphans_remove(ctx
);
1898 perf_pmu_enable(event
->pmu
);
1904 group_sched_in(struct perf_event
*group_event
,
1905 struct perf_cpu_context
*cpuctx
,
1906 struct perf_event_context
*ctx
)
1908 struct perf_event
*event
, *partial_group
= NULL
;
1909 struct pmu
*pmu
= ctx
->pmu
;
1910 u64 now
= ctx
->time
;
1911 bool simulate
= false;
1913 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1916 pmu
->start_txn(pmu
);
1918 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1919 pmu
->cancel_txn(pmu
);
1920 perf_mux_hrtimer_restart(cpuctx
);
1925 * Schedule in siblings as one group (if any):
1927 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1928 if (event_sched_in(event
, cpuctx
, ctx
)) {
1929 partial_group
= event
;
1934 if (!pmu
->commit_txn(pmu
))
1939 * Groups can be scheduled in as one unit only, so undo any
1940 * partial group before returning:
1941 * The events up to the failed event are scheduled out normally,
1942 * tstamp_stopped will be updated.
1944 * The failed events and the remaining siblings need to have
1945 * their timings updated as if they had gone thru event_sched_in()
1946 * and event_sched_out(). This is required to get consistent timings
1947 * across the group. This also takes care of the case where the group
1948 * could never be scheduled by ensuring tstamp_stopped is set to mark
1949 * the time the event was actually stopped, such that time delta
1950 * calculation in update_event_times() is correct.
1952 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1953 if (event
== partial_group
)
1957 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1958 event
->tstamp_stopped
= now
;
1960 event_sched_out(event
, cpuctx
, ctx
);
1963 event_sched_out(group_event
, cpuctx
, ctx
);
1965 pmu
->cancel_txn(pmu
);
1967 perf_mux_hrtimer_restart(cpuctx
);
1973 * Work out whether we can put this event group on the CPU now.
1975 static int group_can_go_on(struct perf_event
*event
,
1976 struct perf_cpu_context
*cpuctx
,
1980 * Groups consisting entirely of software events can always go on.
1982 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1985 * If an exclusive group is already on, no other hardware
1988 if (cpuctx
->exclusive
)
1991 * If this group is exclusive and there are already
1992 * events on the CPU, it can't go on.
1994 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1997 * Otherwise, try to add it if all previous groups were able
2003 static void add_event_to_ctx(struct perf_event
*event
,
2004 struct perf_event_context
*ctx
)
2006 u64 tstamp
= perf_event_time(event
);
2008 list_add_event(event
, ctx
);
2009 perf_group_attach(event
);
2010 event
->tstamp_enabled
= tstamp
;
2011 event
->tstamp_running
= tstamp
;
2012 event
->tstamp_stopped
= tstamp
;
2015 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
2017 ctx_sched_in(struct perf_event_context
*ctx
,
2018 struct perf_cpu_context
*cpuctx
,
2019 enum event_type_t event_type
,
2020 struct task_struct
*task
);
2022 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2023 struct perf_event_context
*ctx
,
2024 struct task_struct
*task
)
2026 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2028 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2029 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2031 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2035 * Cross CPU call to install and enable a performance event
2037 * Must be called with ctx->mutex held
2039 static int __perf_install_in_context(void *info
)
2041 struct perf_event
*event
= info
;
2042 struct perf_event_context
*ctx
= event
->ctx
;
2043 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2044 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2045 struct task_struct
*task
= current
;
2047 perf_ctx_lock(cpuctx
, task_ctx
);
2048 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2051 * If there was an active task_ctx schedule it out.
2054 task_ctx_sched_out(task_ctx
);
2057 * If the context we're installing events in is not the
2058 * active task_ctx, flip them.
2060 if (ctx
->task
&& task_ctx
!= ctx
) {
2062 raw_spin_unlock(&task_ctx
->lock
);
2063 raw_spin_lock(&ctx
->lock
);
2068 cpuctx
->task_ctx
= task_ctx
;
2069 task
= task_ctx
->task
;
2072 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2074 update_context_time(ctx
);
2076 * update cgrp time only if current cgrp
2077 * matches event->cgrp. Must be done before
2078 * calling add_event_to_ctx()
2080 update_cgrp_time_from_event(event
);
2082 add_event_to_ctx(event
, ctx
);
2085 * Schedule everything back in
2087 perf_event_sched_in(cpuctx
, task_ctx
, task
);
2089 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2090 perf_ctx_unlock(cpuctx
, task_ctx
);
2096 * Attach a performance event to a context
2098 * First we add the event to the list with the hardware enable bit
2099 * in event->hw_config cleared.
2101 * If the event is attached to a task which is on a CPU we use a smp
2102 * call to enable it in the task context. The task might have been
2103 * scheduled away, but we check this in the smp call again.
2106 perf_install_in_context(struct perf_event_context
*ctx
,
2107 struct perf_event
*event
,
2110 struct task_struct
*task
= ctx
->task
;
2112 lockdep_assert_held(&ctx
->mutex
);
2115 if (event
->cpu
!= -1)
2120 * Per cpu events are installed via an smp call and
2121 * the install is always successful.
2123 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2128 if (!task_function_call(task
, __perf_install_in_context
, event
))
2131 raw_spin_lock_irq(&ctx
->lock
);
2133 * If we failed to find a running task, but find the context active now
2134 * that we've acquired the ctx->lock, retry.
2136 if (ctx
->is_active
) {
2137 raw_spin_unlock_irq(&ctx
->lock
);
2139 * Reload the task pointer, it might have been changed by
2140 * a concurrent perf_event_context_sched_out().
2147 * Since the task isn't running, its safe to add the event, us holding
2148 * the ctx->lock ensures the task won't get scheduled in.
2150 add_event_to_ctx(event
, ctx
);
2151 raw_spin_unlock_irq(&ctx
->lock
);
2155 * Put a event into inactive state and update time fields.
2156 * Enabling the leader of a group effectively enables all
2157 * the group members that aren't explicitly disabled, so we
2158 * have to update their ->tstamp_enabled also.
2159 * Note: this works for group members as well as group leaders
2160 * since the non-leader members' sibling_lists will be empty.
2162 static void __perf_event_mark_enabled(struct perf_event
*event
)
2164 struct perf_event
*sub
;
2165 u64 tstamp
= perf_event_time(event
);
2167 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2168 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2169 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2170 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2171 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2176 * Cross CPU call to enable a performance event
2178 static int __perf_event_enable(void *info
)
2180 struct perf_event
*event
= info
;
2181 struct perf_event_context
*ctx
= event
->ctx
;
2182 struct perf_event
*leader
= event
->group_leader
;
2183 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2187 * There's a time window between 'ctx->is_active' check
2188 * in perf_event_enable function and this place having:
2190 * - ctx->lock unlocked
2192 * where the task could be killed and 'ctx' deactivated
2193 * by perf_event_exit_task.
2195 if (!ctx
->is_active
)
2198 raw_spin_lock(&ctx
->lock
);
2199 update_context_time(ctx
);
2201 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2205 * set current task's cgroup time reference point
2207 perf_cgroup_set_timestamp(current
, ctx
);
2209 __perf_event_mark_enabled(event
);
2211 if (!event_filter_match(event
)) {
2212 if (is_cgroup_event(event
))
2213 perf_cgroup_defer_enabled(event
);
2218 * If the event is in a group and isn't the group leader,
2219 * then don't put it on unless the group is on.
2221 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2224 if (!group_can_go_on(event
, cpuctx
, 1)) {
2227 if (event
== leader
)
2228 err
= group_sched_in(event
, cpuctx
, ctx
);
2230 err
= event_sched_in(event
, cpuctx
, ctx
);
2235 * If this event can't go on and it's part of a
2236 * group, then the whole group has to come off.
2238 if (leader
!= event
) {
2239 group_sched_out(leader
, cpuctx
, ctx
);
2240 perf_mux_hrtimer_restart(cpuctx
);
2242 if (leader
->attr
.pinned
) {
2243 update_group_times(leader
);
2244 leader
->state
= PERF_EVENT_STATE_ERROR
;
2249 raw_spin_unlock(&ctx
->lock
);
2257 * If event->ctx is a cloned context, callers must make sure that
2258 * every task struct that event->ctx->task could possibly point to
2259 * remains valid. This condition is satisfied when called through
2260 * perf_event_for_each_child or perf_event_for_each as described
2261 * for perf_event_disable.
2263 static void _perf_event_enable(struct perf_event
*event
)
2265 struct perf_event_context
*ctx
= event
->ctx
;
2266 struct task_struct
*task
= ctx
->task
;
2270 * Enable the event on the cpu that it's on
2272 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2276 raw_spin_lock_irq(&ctx
->lock
);
2277 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2281 * If the event is in error state, clear that first.
2282 * That way, if we see the event in error state below, we
2283 * know that it has gone back into error state, as distinct
2284 * from the task having been scheduled away before the
2285 * cross-call arrived.
2287 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2288 event
->state
= PERF_EVENT_STATE_OFF
;
2291 if (!ctx
->is_active
) {
2292 __perf_event_mark_enabled(event
);
2296 raw_spin_unlock_irq(&ctx
->lock
);
2298 if (!task_function_call(task
, __perf_event_enable
, event
))
2301 raw_spin_lock_irq(&ctx
->lock
);
2304 * If the context is active and the event is still off,
2305 * we need to retry the cross-call.
2307 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2309 * task could have been flipped by a concurrent
2310 * perf_event_context_sched_out()
2317 raw_spin_unlock_irq(&ctx
->lock
);
2321 * See perf_event_disable();
2323 void perf_event_enable(struct perf_event
*event
)
2325 struct perf_event_context
*ctx
;
2327 ctx
= perf_event_ctx_lock(event
);
2328 _perf_event_enable(event
);
2329 perf_event_ctx_unlock(event
, ctx
);
2331 EXPORT_SYMBOL_GPL(perf_event_enable
);
2333 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2336 * not supported on inherited events
2338 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2341 atomic_add(refresh
, &event
->event_limit
);
2342 _perf_event_enable(event
);
2348 * See perf_event_disable()
2350 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2352 struct perf_event_context
*ctx
;
2355 ctx
= perf_event_ctx_lock(event
);
2356 ret
= _perf_event_refresh(event
, refresh
);
2357 perf_event_ctx_unlock(event
, ctx
);
2361 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2363 static void ctx_sched_out(struct perf_event_context
*ctx
,
2364 struct perf_cpu_context
*cpuctx
,
2365 enum event_type_t event_type
)
2367 struct perf_event
*event
;
2368 int is_active
= ctx
->is_active
;
2370 ctx
->is_active
&= ~event_type
;
2371 if (likely(!ctx
->nr_events
))
2374 update_context_time(ctx
);
2375 update_cgrp_time_from_cpuctx(cpuctx
);
2376 if (!ctx
->nr_active
)
2379 perf_pmu_disable(ctx
->pmu
);
2380 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2381 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2382 group_sched_out(event
, cpuctx
, ctx
);
2385 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2386 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2387 group_sched_out(event
, cpuctx
, ctx
);
2389 perf_pmu_enable(ctx
->pmu
);
2393 * Test whether two contexts are equivalent, i.e. whether they have both been
2394 * cloned from the same version of the same context.
2396 * Equivalence is measured using a generation number in the context that is
2397 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2398 * and list_del_event().
2400 static int context_equiv(struct perf_event_context
*ctx1
,
2401 struct perf_event_context
*ctx2
)
2403 lockdep_assert_held(&ctx1
->lock
);
2404 lockdep_assert_held(&ctx2
->lock
);
2406 /* Pinning disables the swap optimization */
2407 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2410 /* If ctx1 is the parent of ctx2 */
2411 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2414 /* If ctx2 is the parent of ctx1 */
2415 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2419 * If ctx1 and ctx2 have the same parent; we flatten the parent
2420 * hierarchy, see perf_event_init_context().
2422 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2423 ctx1
->parent_gen
== ctx2
->parent_gen
)
2430 static void __perf_event_sync_stat(struct perf_event
*event
,
2431 struct perf_event
*next_event
)
2435 if (!event
->attr
.inherit_stat
)
2439 * Update the event value, we cannot use perf_event_read()
2440 * because we're in the middle of a context switch and have IRQs
2441 * disabled, which upsets smp_call_function_single(), however
2442 * we know the event must be on the current CPU, therefore we
2443 * don't need to use it.
2445 switch (event
->state
) {
2446 case PERF_EVENT_STATE_ACTIVE
:
2447 event
->pmu
->read(event
);
2450 case PERF_EVENT_STATE_INACTIVE
:
2451 update_event_times(event
);
2459 * In order to keep per-task stats reliable we need to flip the event
2460 * values when we flip the contexts.
2462 value
= local64_read(&next_event
->count
);
2463 value
= local64_xchg(&event
->count
, value
);
2464 local64_set(&next_event
->count
, value
);
2466 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2467 swap(event
->total_time_running
, next_event
->total_time_running
);
2470 * Since we swizzled the values, update the user visible data too.
2472 perf_event_update_userpage(event
);
2473 perf_event_update_userpage(next_event
);
2476 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2477 struct perf_event_context
*next_ctx
)
2479 struct perf_event
*event
, *next_event
;
2484 update_context_time(ctx
);
2486 event
= list_first_entry(&ctx
->event_list
,
2487 struct perf_event
, event_entry
);
2489 next_event
= list_first_entry(&next_ctx
->event_list
,
2490 struct perf_event
, event_entry
);
2492 while (&event
->event_entry
!= &ctx
->event_list
&&
2493 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2495 __perf_event_sync_stat(event
, next_event
);
2497 event
= list_next_entry(event
, event_entry
);
2498 next_event
= list_next_entry(next_event
, event_entry
);
2502 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2503 struct task_struct
*next
)
2505 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2506 struct perf_event_context
*next_ctx
;
2507 struct perf_event_context
*parent
, *next_parent
;
2508 struct perf_cpu_context
*cpuctx
;
2514 cpuctx
= __get_cpu_context(ctx
);
2515 if (!cpuctx
->task_ctx
)
2519 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2523 parent
= rcu_dereference(ctx
->parent_ctx
);
2524 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2526 /* If neither context have a parent context; they cannot be clones. */
2527 if (!parent
&& !next_parent
)
2530 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2532 * Looks like the two contexts are clones, so we might be
2533 * able to optimize the context switch. We lock both
2534 * contexts and check that they are clones under the
2535 * lock (including re-checking that neither has been
2536 * uncloned in the meantime). It doesn't matter which
2537 * order we take the locks because no other cpu could
2538 * be trying to lock both of these tasks.
2540 raw_spin_lock(&ctx
->lock
);
2541 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2542 if (context_equiv(ctx
, next_ctx
)) {
2544 * XXX do we need a memory barrier of sorts
2545 * wrt to rcu_dereference() of perf_event_ctxp
2547 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2548 next
->perf_event_ctxp
[ctxn
] = ctx
;
2550 next_ctx
->task
= task
;
2552 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2556 perf_event_sync_stat(ctx
, next_ctx
);
2558 raw_spin_unlock(&next_ctx
->lock
);
2559 raw_spin_unlock(&ctx
->lock
);
2565 raw_spin_lock(&ctx
->lock
);
2566 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2567 cpuctx
->task_ctx
= NULL
;
2568 raw_spin_unlock(&ctx
->lock
);
2572 void perf_sched_cb_dec(struct pmu
*pmu
)
2574 this_cpu_dec(perf_sched_cb_usages
);
2577 void perf_sched_cb_inc(struct pmu
*pmu
)
2579 this_cpu_inc(perf_sched_cb_usages
);
2583 * This function provides the context switch callback to the lower code
2584 * layer. It is invoked ONLY when the context switch callback is enabled.
2586 static void perf_pmu_sched_task(struct task_struct
*prev
,
2587 struct task_struct
*next
,
2590 struct perf_cpu_context
*cpuctx
;
2592 unsigned long flags
;
2597 local_irq_save(flags
);
2601 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2602 if (pmu
->sched_task
) {
2603 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2605 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2607 perf_pmu_disable(pmu
);
2609 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2611 perf_pmu_enable(pmu
);
2613 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2619 local_irq_restore(flags
);
2622 #define for_each_task_context_nr(ctxn) \
2623 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2626 * Called from scheduler to remove the events of the current task,
2627 * with interrupts disabled.
2629 * We stop each event and update the event value in event->count.
2631 * This does not protect us against NMI, but disable()
2632 * sets the disabled bit in the control field of event _before_
2633 * accessing the event control register. If a NMI hits, then it will
2634 * not restart the event.
2636 void __perf_event_task_sched_out(struct task_struct
*task
,
2637 struct task_struct
*next
)
2641 if (__this_cpu_read(perf_sched_cb_usages
))
2642 perf_pmu_sched_task(task
, next
, false);
2644 for_each_task_context_nr(ctxn
)
2645 perf_event_context_sched_out(task
, ctxn
, next
);
2648 * if cgroup events exist on this CPU, then we need
2649 * to check if we have to switch out PMU state.
2650 * cgroup event are system-wide mode only
2652 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2653 perf_cgroup_sched_out(task
, next
);
2656 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2658 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2660 if (!cpuctx
->task_ctx
)
2663 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2666 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2667 cpuctx
->task_ctx
= NULL
;
2671 * Called with IRQs disabled
2673 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2674 enum event_type_t event_type
)
2676 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2680 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2681 struct perf_cpu_context
*cpuctx
)
2683 struct perf_event
*event
;
2685 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2686 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2688 if (!event_filter_match(event
))
2691 /* may need to reset tstamp_enabled */
2692 if (is_cgroup_event(event
))
2693 perf_cgroup_mark_enabled(event
, ctx
);
2695 if (group_can_go_on(event
, cpuctx
, 1))
2696 group_sched_in(event
, cpuctx
, ctx
);
2699 * If this pinned group hasn't been scheduled,
2700 * put it in error state.
2702 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2703 update_group_times(event
);
2704 event
->state
= PERF_EVENT_STATE_ERROR
;
2710 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2711 struct perf_cpu_context
*cpuctx
)
2713 struct perf_event
*event
;
2716 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2717 /* Ignore events in OFF or ERROR state */
2718 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2721 * Listen to the 'cpu' scheduling filter constraint
2724 if (!event_filter_match(event
))
2727 /* may need to reset tstamp_enabled */
2728 if (is_cgroup_event(event
))
2729 perf_cgroup_mark_enabled(event
, ctx
);
2731 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2732 if (group_sched_in(event
, cpuctx
, ctx
))
2739 ctx_sched_in(struct perf_event_context
*ctx
,
2740 struct perf_cpu_context
*cpuctx
,
2741 enum event_type_t event_type
,
2742 struct task_struct
*task
)
2745 int is_active
= ctx
->is_active
;
2747 ctx
->is_active
|= event_type
;
2748 if (likely(!ctx
->nr_events
))
2752 ctx
->timestamp
= now
;
2753 perf_cgroup_set_timestamp(task
, ctx
);
2755 * First go through the list and put on any pinned groups
2756 * in order to give them the best chance of going on.
2758 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2759 ctx_pinned_sched_in(ctx
, cpuctx
);
2761 /* Then walk through the lower prio flexible groups */
2762 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2763 ctx_flexible_sched_in(ctx
, cpuctx
);
2766 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2767 enum event_type_t event_type
,
2768 struct task_struct
*task
)
2770 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2772 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2775 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2776 struct task_struct
*task
)
2778 struct perf_cpu_context
*cpuctx
;
2780 cpuctx
= __get_cpu_context(ctx
);
2781 if (cpuctx
->task_ctx
== ctx
)
2784 perf_ctx_lock(cpuctx
, ctx
);
2785 perf_pmu_disable(ctx
->pmu
);
2787 * We want to keep the following priority order:
2788 * cpu pinned (that don't need to move), task pinned,
2789 * cpu flexible, task flexible.
2791 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2794 cpuctx
->task_ctx
= ctx
;
2796 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2798 perf_pmu_enable(ctx
->pmu
);
2799 perf_ctx_unlock(cpuctx
, ctx
);
2803 * Called from scheduler to add the events of the current task
2804 * with interrupts disabled.
2806 * We restore the event value and then enable it.
2808 * This does not protect us against NMI, but enable()
2809 * sets the enabled bit in the control field of event _before_
2810 * accessing the event control register. If a NMI hits, then it will
2811 * keep the event running.
2813 void __perf_event_task_sched_in(struct task_struct
*prev
,
2814 struct task_struct
*task
)
2816 struct perf_event_context
*ctx
;
2819 for_each_task_context_nr(ctxn
) {
2820 ctx
= task
->perf_event_ctxp
[ctxn
];
2824 perf_event_context_sched_in(ctx
, task
);
2827 * if cgroup events exist on this CPU, then we need
2828 * to check if we have to switch in PMU state.
2829 * cgroup event are system-wide mode only
2831 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2832 perf_cgroup_sched_in(prev
, task
);
2834 if (__this_cpu_read(perf_sched_cb_usages
))
2835 perf_pmu_sched_task(prev
, task
, true);
2838 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2840 u64 frequency
= event
->attr
.sample_freq
;
2841 u64 sec
= NSEC_PER_SEC
;
2842 u64 divisor
, dividend
;
2844 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2846 count_fls
= fls64(count
);
2847 nsec_fls
= fls64(nsec
);
2848 frequency_fls
= fls64(frequency
);
2852 * We got @count in @nsec, with a target of sample_freq HZ
2853 * the target period becomes:
2856 * period = -------------------
2857 * @nsec * sample_freq
2862 * Reduce accuracy by one bit such that @a and @b converge
2863 * to a similar magnitude.
2865 #define REDUCE_FLS(a, b) \
2867 if (a##_fls > b##_fls) { \
2877 * Reduce accuracy until either term fits in a u64, then proceed with
2878 * the other, so that finally we can do a u64/u64 division.
2880 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2881 REDUCE_FLS(nsec
, frequency
);
2882 REDUCE_FLS(sec
, count
);
2885 if (count_fls
+ sec_fls
> 64) {
2886 divisor
= nsec
* frequency
;
2888 while (count_fls
+ sec_fls
> 64) {
2889 REDUCE_FLS(count
, sec
);
2893 dividend
= count
* sec
;
2895 dividend
= count
* sec
;
2897 while (nsec_fls
+ frequency_fls
> 64) {
2898 REDUCE_FLS(nsec
, frequency
);
2902 divisor
= nsec
* frequency
;
2908 return div64_u64(dividend
, divisor
);
2911 static DEFINE_PER_CPU(int, perf_throttled_count
);
2912 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2914 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2916 struct hw_perf_event
*hwc
= &event
->hw
;
2917 s64 period
, sample_period
;
2920 period
= perf_calculate_period(event
, nsec
, count
);
2922 delta
= (s64
)(period
- hwc
->sample_period
);
2923 delta
= (delta
+ 7) / 8; /* low pass filter */
2925 sample_period
= hwc
->sample_period
+ delta
;
2930 hwc
->sample_period
= sample_period
;
2932 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2934 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2936 local64_set(&hwc
->period_left
, 0);
2939 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2944 * combine freq adjustment with unthrottling to avoid two passes over the
2945 * events. At the same time, make sure, having freq events does not change
2946 * the rate of unthrottling as that would introduce bias.
2948 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2951 struct perf_event
*event
;
2952 struct hw_perf_event
*hwc
;
2953 u64 now
, period
= TICK_NSEC
;
2957 * only need to iterate over all events iff:
2958 * - context have events in frequency mode (needs freq adjust)
2959 * - there are events to unthrottle on this cpu
2961 if (!(ctx
->nr_freq
|| needs_unthr
))
2964 raw_spin_lock(&ctx
->lock
);
2965 perf_pmu_disable(ctx
->pmu
);
2967 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2968 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2971 if (!event_filter_match(event
))
2974 perf_pmu_disable(event
->pmu
);
2978 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2979 hwc
->interrupts
= 0;
2980 perf_log_throttle(event
, 1);
2981 event
->pmu
->start(event
, 0);
2984 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2988 * stop the event and update event->count
2990 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2992 now
= local64_read(&event
->count
);
2993 delta
= now
- hwc
->freq_count_stamp
;
2994 hwc
->freq_count_stamp
= now
;
2998 * reload only if value has changed
2999 * we have stopped the event so tell that
3000 * to perf_adjust_period() to avoid stopping it
3004 perf_adjust_period(event
, period
, delta
, false);
3006 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3008 perf_pmu_enable(event
->pmu
);
3011 perf_pmu_enable(ctx
->pmu
);
3012 raw_spin_unlock(&ctx
->lock
);
3016 * Round-robin a context's events:
3018 static void rotate_ctx(struct perf_event_context
*ctx
)
3021 * Rotate the first entry last of non-pinned groups. Rotation might be
3022 * disabled by the inheritance code.
3024 if (!ctx
->rotate_disable
)
3025 list_rotate_left(&ctx
->flexible_groups
);
3028 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3030 struct perf_event_context
*ctx
= NULL
;
3033 if (cpuctx
->ctx
.nr_events
) {
3034 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3038 ctx
= cpuctx
->task_ctx
;
3039 if (ctx
&& ctx
->nr_events
) {
3040 if (ctx
->nr_events
!= ctx
->nr_active
)
3047 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3048 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3050 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3052 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3054 rotate_ctx(&cpuctx
->ctx
);
3058 perf_event_sched_in(cpuctx
, ctx
, current
);
3060 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3061 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3067 #ifdef CONFIG_NO_HZ_FULL
3068 bool perf_event_can_stop_tick(void)
3070 if (atomic_read(&nr_freq_events
) ||
3071 __this_cpu_read(perf_throttled_count
))
3078 void perf_event_task_tick(void)
3080 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3081 struct perf_event_context
*ctx
, *tmp
;
3084 WARN_ON(!irqs_disabled());
3086 __this_cpu_inc(perf_throttled_seq
);
3087 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3089 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3090 perf_adjust_freq_unthr_context(ctx
, throttled
);
3093 static int event_enable_on_exec(struct perf_event
*event
,
3094 struct perf_event_context
*ctx
)
3096 if (!event
->attr
.enable_on_exec
)
3099 event
->attr
.enable_on_exec
= 0;
3100 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3103 __perf_event_mark_enabled(event
);
3109 * Enable all of a task's events that have been marked enable-on-exec.
3110 * This expects task == current.
3112 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
3114 struct perf_event_context
*clone_ctx
= NULL
;
3115 struct perf_event
*event
;
3116 unsigned long flags
;
3120 local_irq_save(flags
);
3121 if (!ctx
|| !ctx
->nr_events
)
3125 * We must ctxsw out cgroup events to avoid conflict
3126 * when invoking perf_task_event_sched_in() later on
3127 * in this function. Otherwise we end up trying to
3128 * ctxswin cgroup events which are already scheduled
3131 perf_cgroup_sched_out(current
, NULL
);
3133 raw_spin_lock(&ctx
->lock
);
3134 task_ctx_sched_out(ctx
);
3136 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3137 ret
= event_enable_on_exec(event
, ctx
);
3143 * Unclone this context if we enabled any event.
3146 clone_ctx
= unclone_ctx(ctx
);
3148 raw_spin_unlock(&ctx
->lock
);
3151 * Also calls ctxswin for cgroup events, if any:
3153 perf_event_context_sched_in(ctx
, ctx
->task
);
3155 local_irq_restore(flags
);
3161 void perf_event_exec(void)
3163 struct perf_event_context
*ctx
;
3167 for_each_task_context_nr(ctxn
) {
3168 ctx
= current
->perf_event_ctxp
[ctxn
];
3172 perf_event_enable_on_exec(ctx
);
3178 * Cross CPU call to read the hardware event
3180 static void __perf_event_read(void *info
)
3182 struct perf_event
*event
= info
;
3183 struct perf_event_context
*ctx
= event
->ctx
;
3184 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3187 * If this is a task context, we need to check whether it is
3188 * the current task context of this cpu. If not it has been
3189 * scheduled out before the smp call arrived. In that case
3190 * event->count would have been updated to a recent sample
3191 * when the event was scheduled out.
3193 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3196 raw_spin_lock(&ctx
->lock
);
3197 if (ctx
->is_active
) {
3198 update_context_time(ctx
);
3199 update_cgrp_time_from_event(event
);
3201 update_event_times(event
);
3202 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3203 event
->pmu
->read(event
);
3204 raw_spin_unlock(&ctx
->lock
);
3207 static inline u64
perf_event_count(struct perf_event
*event
)
3209 if (event
->pmu
->count
)
3210 return event
->pmu
->count(event
);
3212 return __perf_event_count(event
);
3215 static u64
perf_event_read(struct perf_event
*event
)
3218 * If event is enabled and currently active on a CPU, update the
3219 * value in the event structure:
3221 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3222 smp_call_function_single(event
->oncpu
,
3223 __perf_event_read
, event
, 1);
3224 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3225 struct perf_event_context
*ctx
= event
->ctx
;
3226 unsigned long flags
;
3228 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3230 * may read while context is not active
3231 * (e.g., thread is blocked), in that case
3232 * we cannot update context time
3234 if (ctx
->is_active
) {
3235 update_context_time(ctx
);
3236 update_cgrp_time_from_event(event
);
3238 update_event_times(event
);
3239 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3242 return perf_event_count(event
);
3246 * Initialize the perf_event context in a task_struct:
3248 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3250 raw_spin_lock_init(&ctx
->lock
);
3251 mutex_init(&ctx
->mutex
);
3252 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3253 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3254 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3255 INIT_LIST_HEAD(&ctx
->event_list
);
3256 atomic_set(&ctx
->refcount
, 1);
3257 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3260 static struct perf_event_context
*
3261 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3263 struct perf_event_context
*ctx
;
3265 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3269 __perf_event_init_context(ctx
);
3272 get_task_struct(task
);
3279 static struct task_struct
*
3280 find_lively_task_by_vpid(pid_t vpid
)
3282 struct task_struct
*task
;
3289 task
= find_task_by_vpid(vpid
);
3291 get_task_struct(task
);
3295 return ERR_PTR(-ESRCH
);
3297 /* Reuse ptrace permission checks for now. */
3299 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3304 put_task_struct(task
);
3305 return ERR_PTR(err
);
3310 * Returns a matching context with refcount and pincount.
3312 static struct perf_event_context
*
3313 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3314 struct perf_event
*event
)
3316 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3317 struct perf_cpu_context
*cpuctx
;
3318 void *task_ctx_data
= NULL
;
3319 unsigned long flags
;
3321 int cpu
= event
->cpu
;
3324 /* Must be root to operate on a CPU event: */
3325 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3326 return ERR_PTR(-EACCES
);
3329 * We could be clever and allow to attach a event to an
3330 * offline CPU and activate it when the CPU comes up, but
3333 if (!cpu_online(cpu
))
3334 return ERR_PTR(-ENODEV
);
3336 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3345 ctxn
= pmu
->task_ctx_nr
;
3349 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3350 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3351 if (!task_ctx_data
) {
3358 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3360 clone_ctx
= unclone_ctx(ctx
);
3363 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3364 ctx
->task_ctx_data
= task_ctx_data
;
3365 task_ctx_data
= NULL
;
3367 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3372 ctx
= alloc_perf_context(pmu
, task
);
3377 if (task_ctx_data
) {
3378 ctx
->task_ctx_data
= task_ctx_data
;
3379 task_ctx_data
= NULL
;
3383 mutex_lock(&task
->perf_event_mutex
);
3385 * If it has already passed perf_event_exit_task().
3386 * we must see PF_EXITING, it takes this mutex too.
3388 if (task
->flags
& PF_EXITING
)
3390 else if (task
->perf_event_ctxp
[ctxn
])
3395 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3397 mutex_unlock(&task
->perf_event_mutex
);
3399 if (unlikely(err
)) {
3408 kfree(task_ctx_data
);
3412 kfree(task_ctx_data
);
3413 return ERR_PTR(err
);
3416 static void perf_event_free_filter(struct perf_event
*event
);
3417 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3419 static void free_event_rcu(struct rcu_head
*head
)
3421 struct perf_event
*event
;
3423 event
= container_of(head
, struct perf_event
, rcu_head
);
3425 put_pid_ns(event
->ns
);
3426 perf_event_free_filter(event
);
3430 static void ring_buffer_attach(struct perf_event
*event
,
3431 struct ring_buffer
*rb
);
3433 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3438 if (is_cgroup_event(event
))
3439 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3442 static void unaccount_event(struct perf_event
*event
)
3447 if (event
->attach_state
& PERF_ATTACH_TASK
)
3448 static_key_slow_dec_deferred(&perf_sched_events
);
3449 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3450 atomic_dec(&nr_mmap_events
);
3451 if (event
->attr
.comm
)
3452 atomic_dec(&nr_comm_events
);
3453 if (event
->attr
.task
)
3454 atomic_dec(&nr_task_events
);
3455 if (event
->attr
.freq
)
3456 atomic_dec(&nr_freq_events
);
3457 if (is_cgroup_event(event
))
3458 static_key_slow_dec_deferred(&perf_sched_events
);
3459 if (has_branch_stack(event
))
3460 static_key_slow_dec_deferred(&perf_sched_events
);
3462 unaccount_event_cpu(event
, event
->cpu
);
3466 * The following implement mutual exclusion of events on "exclusive" pmus
3467 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3468 * at a time, so we disallow creating events that might conflict, namely:
3470 * 1) cpu-wide events in the presence of per-task events,
3471 * 2) per-task events in the presence of cpu-wide events,
3472 * 3) two matching events on the same context.
3474 * The former two cases are handled in the allocation path (perf_event_alloc(),
3475 * __free_event()), the latter -- before the first perf_install_in_context().
3477 static int exclusive_event_init(struct perf_event
*event
)
3479 struct pmu
*pmu
= event
->pmu
;
3481 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3485 * Prevent co-existence of per-task and cpu-wide events on the
3486 * same exclusive pmu.
3488 * Negative pmu::exclusive_cnt means there are cpu-wide
3489 * events on this "exclusive" pmu, positive means there are
3492 * Since this is called in perf_event_alloc() path, event::ctx
3493 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3494 * to mean "per-task event", because unlike other attach states it
3495 * never gets cleared.
3497 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3498 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3501 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3508 static void exclusive_event_destroy(struct perf_event
*event
)
3510 struct pmu
*pmu
= event
->pmu
;
3512 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3515 /* see comment in exclusive_event_init() */
3516 if (event
->attach_state
& PERF_ATTACH_TASK
)
3517 atomic_dec(&pmu
->exclusive_cnt
);
3519 atomic_inc(&pmu
->exclusive_cnt
);
3522 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3524 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3525 (e1
->cpu
== e2
->cpu
||
3532 /* Called under the same ctx::mutex as perf_install_in_context() */
3533 static bool exclusive_event_installable(struct perf_event
*event
,
3534 struct perf_event_context
*ctx
)
3536 struct perf_event
*iter_event
;
3537 struct pmu
*pmu
= event
->pmu
;
3539 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3542 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3543 if (exclusive_event_match(iter_event
, event
))
3550 static void __free_event(struct perf_event
*event
)
3552 if (!event
->parent
) {
3553 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3554 put_callchain_buffers();
3557 perf_event_free_bpf_prog(event
);
3560 event
->destroy(event
);
3563 put_ctx(event
->ctx
);
3566 exclusive_event_destroy(event
);
3567 module_put(event
->pmu
->module
);
3570 call_rcu(&event
->rcu_head
, free_event_rcu
);
3573 static void _free_event(struct perf_event
*event
)
3575 irq_work_sync(&event
->pending
);
3577 unaccount_event(event
);
3581 * Can happen when we close an event with re-directed output.
3583 * Since we have a 0 refcount, perf_mmap_close() will skip
3584 * over us; possibly making our ring_buffer_put() the last.
3586 mutex_lock(&event
->mmap_mutex
);
3587 ring_buffer_attach(event
, NULL
);
3588 mutex_unlock(&event
->mmap_mutex
);
3591 if (is_cgroup_event(event
))
3592 perf_detach_cgroup(event
);
3594 __free_event(event
);
3598 * Used to free events which have a known refcount of 1, such as in error paths
3599 * where the event isn't exposed yet and inherited events.
3601 static void free_event(struct perf_event
*event
)
3603 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3604 "unexpected event refcount: %ld; ptr=%p\n",
3605 atomic_long_read(&event
->refcount
), event
)) {
3606 /* leak to avoid use-after-free */
3614 * Remove user event from the owner task.
3616 static void perf_remove_from_owner(struct perf_event
*event
)
3618 struct task_struct
*owner
;
3621 owner
= ACCESS_ONCE(event
->owner
);
3623 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3624 * !owner it means the list deletion is complete and we can indeed
3625 * free this event, otherwise we need to serialize on
3626 * owner->perf_event_mutex.
3628 smp_read_barrier_depends();
3631 * Since delayed_put_task_struct() also drops the last
3632 * task reference we can safely take a new reference
3633 * while holding the rcu_read_lock().
3635 get_task_struct(owner
);
3641 * If we're here through perf_event_exit_task() we're already
3642 * holding ctx->mutex which would be an inversion wrt. the
3643 * normal lock order.
3645 * However we can safely take this lock because its the child
3648 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3651 * We have to re-check the event->owner field, if it is cleared
3652 * we raced with perf_event_exit_task(), acquiring the mutex
3653 * ensured they're done, and we can proceed with freeing the
3657 list_del_init(&event
->owner_entry
);
3658 mutex_unlock(&owner
->perf_event_mutex
);
3659 put_task_struct(owner
);
3663 static void put_event(struct perf_event
*event
)
3665 struct perf_event_context
*ctx
;
3667 if (!atomic_long_dec_and_test(&event
->refcount
))
3670 if (!is_kernel_event(event
))
3671 perf_remove_from_owner(event
);
3674 * There are two ways this annotation is useful:
3676 * 1) there is a lock recursion from perf_event_exit_task
3677 * see the comment there.
3679 * 2) there is a lock-inversion with mmap_sem through
3680 * perf_event_read_group(), which takes faults while
3681 * holding ctx->mutex, however this is called after
3682 * the last filedesc died, so there is no possibility
3683 * to trigger the AB-BA case.
3685 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3686 WARN_ON_ONCE(ctx
->parent_ctx
);
3687 perf_remove_from_context(event
, true);
3688 perf_event_ctx_unlock(event
, ctx
);
3693 int perf_event_release_kernel(struct perf_event
*event
)
3698 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3701 * Called when the last reference to the file is gone.
3703 static int perf_release(struct inode
*inode
, struct file
*file
)
3705 put_event(file
->private_data
);
3710 * Remove all orphanes events from the context.
3712 static void orphans_remove_work(struct work_struct
*work
)
3714 struct perf_event_context
*ctx
;
3715 struct perf_event
*event
, *tmp
;
3717 ctx
= container_of(work
, struct perf_event_context
,
3718 orphans_remove
.work
);
3720 mutex_lock(&ctx
->mutex
);
3721 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3722 struct perf_event
*parent_event
= event
->parent
;
3724 if (!is_orphaned_child(event
))
3727 perf_remove_from_context(event
, true);
3729 mutex_lock(&parent_event
->child_mutex
);
3730 list_del_init(&event
->child_list
);
3731 mutex_unlock(&parent_event
->child_mutex
);
3734 put_event(parent_event
);
3737 raw_spin_lock_irq(&ctx
->lock
);
3738 ctx
->orphans_remove_sched
= false;
3739 raw_spin_unlock_irq(&ctx
->lock
);
3740 mutex_unlock(&ctx
->mutex
);
3745 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3747 struct perf_event
*child
;
3753 mutex_lock(&event
->child_mutex
);
3754 total
+= perf_event_read(event
);
3755 *enabled
+= event
->total_time_enabled
+
3756 atomic64_read(&event
->child_total_time_enabled
);
3757 *running
+= event
->total_time_running
+
3758 atomic64_read(&event
->child_total_time_running
);
3760 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3761 total
+= perf_event_read(child
);
3762 *enabled
+= child
->total_time_enabled
;
3763 *running
+= child
->total_time_running
;
3765 mutex_unlock(&event
->child_mutex
);
3769 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3771 static int perf_event_read_group(struct perf_event
*event
,
3772 u64 read_format
, char __user
*buf
)
3774 struct perf_event
*leader
= event
->group_leader
, *sub
;
3775 struct perf_event_context
*ctx
= leader
->ctx
;
3776 int n
= 0, size
= 0, ret
;
3777 u64 count
, enabled
, running
;
3780 lockdep_assert_held(&ctx
->mutex
);
3782 count
= perf_event_read_value(leader
, &enabled
, &running
);
3784 values
[n
++] = 1 + leader
->nr_siblings
;
3785 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3786 values
[n
++] = enabled
;
3787 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3788 values
[n
++] = running
;
3789 values
[n
++] = count
;
3790 if (read_format
& PERF_FORMAT_ID
)
3791 values
[n
++] = primary_event_id(leader
);
3793 size
= n
* sizeof(u64
);
3795 if (copy_to_user(buf
, values
, size
))
3800 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3803 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3804 if (read_format
& PERF_FORMAT_ID
)
3805 values
[n
++] = primary_event_id(sub
);
3807 size
= n
* sizeof(u64
);
3809 if (copy_to_user(buf
+ ret
, values
, size
)) {
3819 static int perf_event_read_one(struct perf_event
*event
,
3820 u64 read_format
, char __user
*buf
)
3822 u64 enabled
, running
;
3826 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3827 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3828 values
[n
++] = enabled
;
3829 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3830 values
[n
++] = running
;
3831 if (read_format
& PERF_FORMAT_ID
)
3832 values
[n
++] = primary_event_id(event
);
3834 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3837 return n
* sizeof(u64
);
3840 static bool is_event_hup(struct perf_event
*event
)
3844 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
3847 mutex_lock(&event
->child_mutex
);
3848 no_children
= list_empty(&event
->child_list
);
3849 mutex_unlock(&event
->child_mutex
);
3854 * Read the performance event - simple non blocking version for now
3857 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3859 u64 read_format
= event
->attr
.read_format
;
3863 * Return end-of-file for a read on a event that is in
3864 * error state (i.e. because it was pinned but it couldn't be
3865 * scheduled on to the CPU at some point).
3867 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3870 if (count
< event
->read_size
)
3873 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3874 if (read_format
& PERF_FORMAT_GROUP
)
3875 ret
= perf_event_read_group(event
, read_format
, buf
);
3877 ret
= perf_event_read_one(event
, read_format
, buf
);
3883 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3885 struct perf_event
*event
= file
->private_data
;
3886 struct perf_event_context
*ctx
;
3889 ctx
= perf_event_ctx_lock(event
);
3890 ret
= perf_read_hw(event
, buf
, count
);
3891 perf_event_ctx_unlock(event
, ctx
);
3896 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3898 struct perf_event
*event
= file
->private_data
;
3899 struct ring_buffer
*rb
;
3900 unsigned int events
= POLLHUP
;
3902 poll_wait(file
, &event
->waitq
, wait
);
3904 if (is_event_hup(event
))
3908 * Pin the event->rb by taking event->mmap_mutex; otherwise
3909 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
3911 mutex_lock(&event
->mmap_mutex
);
3914 events
= atomic_xchg(&rb
->poll
, 0);
3915 mutex_unlock(&event
->mmap_mutex
);
3919 static void _perf_event_reset(struct perf_event
*event
)
3921 (void)perf_event_read(event
);
3922 local64_set(&event
->count
, 0);
3923 perf_event_update_userpage(event
);
3927 * Holding the top-level event's child_mutex means that any
3928 * descendant process that has inherited this event will block
3929 * in sync_child_event if it goes to exit, thus satisfying the
3930 * task existence requirements of perf_event_enable/disable.
3932 static void perf_event_for_each_child(struct perf_event
*event
,
3933 void (*func
)(struct perf_event
*))
3935 struct perf_event
*child
;
3937 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3939 mutex_lock(&event
->child_mutex
);
3941 list_for_each_entry(child
, &event
->child_list
, child_list
)
3943 mutex_unlock(&event
->child_mutex
);
3946 static void perf_event_for_each(struct perf_event
*event
,
3947 void (*func
)(struct perf_event
*))
3949 struct perf_event_context
*ctx
= event
->ctx
;
3950 struct perf_event
*sibling
;
3952 lockdep_assert_held(&ctx
->mutex
);
3954 event
= event
->group_leader
;
3956 perf_event_for_each_child(event
, func
);
3957 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3958 perf_event_for_each_child(sibling
, func
);
3961 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3963 struct perf_event_context
*ctx
= event
->ctx
;
3964 int ret
= 0, active
;
3967 if (!is_sampling_event(event
))
3970 if (copy_from_user(&value
, arg
, sizeof(value
)))
3976 raw_spin_lock_irq(&ctx
->lock
);
3977 if (event
->attr
.freq
) {
3978 if (value
> sysctl_perf_event_sample_rate
) {
3983 event
->attr
.sample_freq
= value
;
3985 event
->attr
.sample_period
= value
;
3986 event
->hw
.sample_period
= value
;
3989 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
3991 perf_pmu_disable(ctx
->pmu
);
3992 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3995 local64_set(&event
->hw
.period_left
, 0);
3998 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3999 perf_pmu_enable(ctx
->pmu
);
4003 raw_spin_unlock_irq(&ctx
->lock
);
4008 static const struct file_operations perf_fops
;
4010 static inline int perf_fget_light(int fd
, struct fd
*p
)
4012 struct fd f
= fdget(fd
);
4016 if (f
.file
->f_op
!= &perf_fops
) {
4024 static int perf_event_set_output(struct perf_event
*event
,
4025 struct perf_event
*output_event
);
4026 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4027 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4029 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4031 void (*func
)(struct perf_event
*);
4035 case PERF_EVENT_IOC_ENABLE
:
4036 func
= _perf_event_enable
;
4038 case PERF_EVENT_IOC_DISABLE
:
4039 func
= _perf_event_disable
;
4041 case PERF_EVENT_IOC_RESET
:
4042 func
= _perf_event_reset
;
4045 case PERF_EVENT_IOC_REFRESH
:
4046 return _perf_event_refresh(event
, arg
);
4048 case PERF_EVENT_IOC_PERIOD
:
4049 return perf_event_period(event
, (u64 __user
*)arg
);
4051 case PERF_EVENT_IOC_ID
:
4053 u64 id
= primary_event_id(event
);
4055 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4060 case PERF_EVENT_IOC_SET_OUTPUT
:
4064 struct perf_event
*output_event
;
4066 ret
= perf_fget_light(arg
, &output
);
4069 output_event
= output
.file
->private_data
;
4070 ret
= perf_event_set_output(event
, output_event
);
4073 ret
= perf_event_set_output(event
, NULL
);
4078 case PERF_EVENT_IOC_SET_FILTER
:
4079 return perf_event_set_filter(event
, (void __user
*)arg
);
4081 case PERF_EVENT_IOC_SET_BPF
:
4082 return perf_event_set_bpf_prog(event
, arg
);
4088 if (flags
& PERF_IOC_FLAG_GROUP
)
4089 perf_event_for_each(event
, func
);
4091 perf_event_for_each_child(event
, func
);
4096 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4098 struct perf_event
*event
= file
->private_data
;
4099 struct perf_event_context
*ctx
;
4102 ctx
= perf_event_ctx_lock(event
);
4103 ret
= _perf_ioctl(event
, cmd
, arg
);
4104 perf_event_ctx_unlock(event
, ctx
);
4109 #ifdef CONFIG_COMPAT
4110 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4113 switch (_IOC_NR(cmd
)) {
4114 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4115 case _IOC_NR(PERF_EVENT_IOC_ID
):
4116 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4117 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4118 cmd
&= ~IOCSIZE_MASK
;
4119 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4123 return perf_ioctl(file
, cmd
, arg
);
4126 # define perf_compat_ioctl NULL
4129 int perf_event_task_enable(void)
4131 struct perf_event_context
*ctx
;
4132 struct perf_event
*event
;
4134 mutex_lock(¤t
->perf_event_mutex
);
4135 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4136 ctx
= perf_event_ctx_lock(event
);
4137 perf_event_for_each_child(event
, _perf_event_enable
);
4138 perf_event_ctx_unlock(event
, ctx
);
4140 mutex_unlock(¤t
->perf_event_mutex
);
4145 int perf_event_task_disable(void)
4147 struct perf_event_context
*ctx
;
4148 struct perf_event
*event
;
4150 mutex_lock(¤t
->perf_event_mutex
);
4151 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4152 ctx
= perf_event_ctx_lock(event
);
4153 perf_event_for_each_child(event
, _perf_event_disable
);
4154 perf_event_ctx_unlock(event
, ctx
);
4156 mutex_unlock(¤t
->perf_event_mutex
);
4161 static int perf_event_index(struct perf_event
*event
)
4163 if (event
->hw
.state
& PERF_HES_STOPPED
)
4166 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4169 return event
->pmu
->event_idx(event
);
4172 static void calc_timer_values(struct perf_event
*event
,
4179 *now
= perf_clock();
4180 ctx_time
= event
->shadow_ctx_time
+ *now
;
4181 *enabled
= ctx_time
- event
->tstamp_enabled
;
4182 *running
= ctx_time
- event
->tstamp_running
;
4185 static void perf_event_init_userpage(struct perf_event
*event
)
4187 struct perf_event_mmap_page
*userpg
;
4188 struct ring_buffer
*rb
;
4191 rb
= rcu_dereference(event
->rb
);
4195 userpg
= rb
->user_page
;
4197 /* Allow new userspace to detect that bit 0 is deprecated */
4198 userpg
->cap_bit0_is_deprecated
= 1;
4199 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4200 userpg
->data_offset
= PAGE_SIZE
;
4201 userpg
->data_size
= perf_data_size(rb
);
4207 void __weak
arch_perf_update_userpage(
4208 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4213 * Callers need to ensure there can be no nesting of this function, otherwise
4214 * the seqlock logic goes bad. We can not serialize this because the arch
4215 * code calls this from NMI context.
4217 void perf_event_update_userpage(struct perf_event
*event
)
4219 struct perf_event_mmap_page
*userpg
;
4220 struct ring_buffer
*rb
;
4221 u64 enabled
, running
, now
;
4224 rb
= rcu_dereference(event
->rb
);
4229 * compute total_time_enabled, total_time_running
4230 * based on snapshot values taken when the event
4231 * was last scheduled in.
4233 * we cannot simply called update_context_time()
4234 * because of locking issue as we can be called in
4237 calc_timer_values(event
, &now
, &enabled
, &running
);
4239 userpg
= rb
->user_page
;
4241 * Disable preemption so as to not let the corresponding user-space
4242 * spin too long if we get preempted.
4247 userpg
->index
= perf_event_index(event
);
4248 userpg
->offset
= perf_event_count(event
);
4250 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4252 userpg
->time_enabled
= enabled
+
4253 atomic64_read(&event
->child_total_time_enabled
);
4255 userpg
->time_running
= running
+
4256 atomic64_read(&event
->child_total_time_running
);
4258 arch_perf_update_userpage(event
, userpg
, now
);
4267 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4269 struct perf_event
*event
= vma
->vm_file
->private_data
;
4270 struct ring_buffer
*rb
;
4271 int ret
= VM_FAULT_SIGBUS
;
4273 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4274 if (vmf
->pgoff
== 0)
4280 rb
= rcu_dereference(event
->rb
);
4284 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4287 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4291 get_page(vmf
->page
);
4292 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4293 vmf
->page
->index
= vmf
->pgoff
;
4302 static void ring_buffer_attach(struct perf_event
*event
,
4303 struct ring_buffer
*rb
)
4305 struct ring_buffer
*old_rb
= NULL
;
4306 unsigned long flags
;
4310 * Should be impossible, we set this when removing
4311 * event->rb_entry and wait/clear when adding event->rb_entry.
4313 WARN_ON_ONCE(event
->rcu_pending
);
4316 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4317 list_del_rcu(&event
->rb_entry
);
4318 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4320 event
->rcu_batches
= get_state_synchronize_rcu();
4321 event
->rcu_pending
= 1;
4325 if (event
->rcu_pending
) {
4326 cond_synchronize_rcu(event
->rcu_batches
);
4327 event
->rcu_pending
= 0;
4330 spin_lock_irqsave(&rb
->event_lock
, flags
);
4331 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4332 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4335 rcu_assign_pointer(event
->rb
, rb
);
4338 ring_buffer_put(old_rb
);
4340 * Since we detached before setting the new rb, so that we
4341 * could attach the new rb, we could have missed a wakeup.
4344 wake_up_all(&event
->waitq
);
4348 static void ring_buffer_wakeup(struct perf_event
*event
)
4350 struct ring_buffer
*rb
;
4353 rb
= rcu_dereference(event
->rb
);
4355 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4356 wake_up_all(&event
->waitq
);
4361 static void rb_free_rcu(struct rcu_head
*rcu_head
)
4363 struct ring_buffer
*rb
;
4365 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
4369 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4371 struct ring_buffer
*rb
;
4374 rb
= rcu_dereference(event
->rb
);
4376 if (!atomic_inc_not_zero(&rb
->refcount
))
4384 void ring_buffer_put(struct ring_buffer
*rb
)
4386 if (!atomic_dec_and_test(&rb
->refcount
))
4389 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4391 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4394 static void perf_mmap_open(struct vm_area_struct
*vma
)
4396 struct perf_event
*event
= vma
->vm_file
->private_data
;
4398 atomic_inc(&event
->mmap_count
);
4399 atomic_inc(&event
->rb
->mmap_count
);
4402 atomic_inc(&event
->rb
->aux_mmap_count
);
4404 if (event
->pmu
->event_mapped
)
4405 event
->pmu
->event_mapped(event
);
4409 * A buffer can be mmap()ed multiple times; either directly through the same
4410 * event, or through other events by use of perf_event_set_output().
4412 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4413 * the buffer here, where we still have a VM context. This means we need
4414 * to detach all events redirecting to us.
4416 static void perf_mmap_close(struct vm_area_struct
*vma
)
4418 struct perf_event
*event
= vma
->vm_file
->private_data
;
4420 struct ring_buffer
*rb
= ring_buffer_get(event
);
4421 struct user_struct
*mmap_user
= rb
->mmap_user
;
4422 int mmap_locked
= rb
->mmap_locked
;
4423 unsigned long size
= perf_data_size(rb
);
4425 if (event
->pmu
->event_unmapped
)
4426 event
->pmu
->event_unmapped(event
);
4429 * rb->aux_mmap_count will always drop before rb->mmap_count and
4430 * event->mmap_count, so it is ok to use event->mmap_mutex to
4431 * serialize with perf_mmap here.
4433 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4434 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4435 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4436 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4439 mutex_unlock(&event
->mmap_mutex
);
4442 atomic_dec(&rb
->mmap_count
);
4444 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4447 ring_buffer_attach(event
, NULL
);
4448 mutex_unlock(&event
->mmap_mutex
);
4450 /* If there's still other mmap()s of this buffer, we're done. */
4451 if (atomic_read(&rb
->mmap_count
))
4455 * No other mmap()s, detach from all other events that might redirect
4456 * into the now unreachable buffer. Somewhat complicated by the
4457 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4461 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4462 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4464 * This event is en-route to free_event() which will
4465 * detach it and remove it from the list.
4471 mutex_lock(&event
->mmap_mutex
);
4473 * Check we didn't race with perf_event_set_output() which can
4474 * swizzle the rb from under us while we were waiting to
4475 * acquire mmap_mutex.
4477 * If we find a different rb; ignore this event, a next
4478 * iteration will no longer find it on the list. We have to
4479 * still restart the iteration to make sure we're not now
4480 * iterating the wrong list.
4482 if (event
->rb
== rb
)
4483 ring_buffer_attach(event
, NULL
);
4485 mutex_unlock(&event
->mmap_mutex
);
4489 * Restart the iteration; either we're on the wrong list or
4490 * destroyed its integrity by doing a deletion.
4497 * It could be there's still a few 0-ref events on the list; they'll
4498 * get cleaned up by free_event() -- they'll also still have their
4499 * ref on the rb and will free it whenever they are done with it.
4501 * Aside from that, this buffer is 'fully' detached and unmapped,
4502 * undo the VM accounting.
4505 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4506 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4507 free_uid(mmap_user
);
4510 ring_buffer_put(rb
); /* could be last */
4513 static const struct vm_operations_struct perf_mmap_vmops
= {
4514 .open
= perf_mmap_open
,
4515 .close
= perf_mmap_close
, /* non mergable */
4516 .fault
= perf_mmap_fault
,
4517 .page_mkwrite
= perf_mmap_fault
,
4520 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4522 struct perf_event
*event
= file
->private_data
;
4523 unsigned long user_locked
, user_lock_limit
;
4524 struct user_struct
*user
= current_user();
4525 unsigned long locked
, lock_limit
;
4526 struct ring_buffer
*rb
= NULL
;
4527 unsigned long vma_size
;
4528 unsigned long nr_pages
;
4529 long user_extra
= 0, extra
= 0;
4530 int ret
= 0, flags
= 0;
4533 * Don't allow mmap() of inherited per-task counters. This would
4534 * create a performance issue due to all children writing to the
4537 if (event
->cpu
== -1 && event
->attr
.inherit
)
4540 if (!(vma
->vm_flags
& VM_SHARED
))
4543 vma_size
= vma
->vm_end
- vma
->vm_start
;
4545 if (vma
->vm_pgoff
== 0) {
4546 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4549 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4550 * mapped, all subsequent mappings should have the same size
4551 * and offset. Must be above the normal perf buffer.
4553 u64 aux_offset
, aux_size
;
4558 nr_pages
= vma_size
/ PAGE_SIZE
;
4560 mutex_lock(&event
->mmap_mutex
);
4567 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4568 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4570 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4573 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4576 /* already mapped with a different offset */
4577 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4580 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4583 /* already mapped with a different size */
4584 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4587 if (!is_power_of_2(nr_pages
))
4590 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4593 if (rb_has_aux(rb
)) {
4594 atomic_inc(&rb
->aux_mmap_count
);
4599 atomic_set(&rb
->aux_mmap_count
, 1);
4600 user_extra
= nr_pages
;
4606 * If we have rb pages ensure they're a power-of-two number, so we
4607 * can do bitmasks instead of modulo.
4609 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4612 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4615 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4617 mutex_lock(&event
->mmap_mutex
);
4619 if (event
->rb
->nr_pages
!= nr_pages
) {
4624 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4626 * Raced against perf_mmap_close() through
4627 * perf_event_set_output(). Try again, hope for better
4630 mutex_unlock(&event
->mmap_mutex
);
4637 user_extra
= nr_pages
+ 1;
4640 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4643 * Increase the limit linearly with more CPUs:
4645 user_lock_limit
*= num_online_cpus();
4647 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4649 if (user_locked
> user_lock_limit
)
4650 extra
= user_locked
- user_lock_limit
;
4652 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4653 lock_limit
>>= PAGE_SHIFT
;
4654 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4656 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4657 !capable(CAP_IPC_LOCK
)) {
4662 WARN_ON(!rb
&& event
->rb
);
4664 if (vma
->vm_flags
& VM_WRITE
)
4665 flags
|= RING_BUFFER_WRITABLE
;
4668 rb
= rb_alloc(nr_pages
,
4669 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4677 atomic_set(&rb
->mmap_count
, 1);
4678 rb
->mmap_user
= get_current_user();
4679 rb
->mmap_locked
= extra
;
4681 ring_buffer_attach(event
, rb
);
4683 perf_event_init_userpage(event
);
4684 perf_event_update_userpage(event
);
4686 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4687 event
->attr
.aux_watermark
, flags
);
4689 rb
->aux_mmap_locked
= extra
;
4694 atomic_long_add(user_extra
, &user
->locked_vm
);
4695 vma
->vm_mm
->pinned_vm
+= extra
;
4697 atomic_inc(&event
->mmap_count
);
4699 atomic_dec(&rb
->mmap_count
);
4702 mutex_unlock(&event
->mmap_mutex
);
4705 * Since pinned accounting is per vm we cannot allow fork() to copy our
4708 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4709 vma
->vm_ops
= &perf_mmap_vmops
;
4711 if (event
->pmu
->event_mapped
)
4712 event
->pmu
->event_mapped(event
);
4717 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4719 struct inode
*inode
= file_inode(filp
);
4720 struct perf_event
*event
= filp
->private_data
;
4723 mutex_lock(&inode
->i_mutex
);
4724 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4725 mutex_unlock(&inode
->i_mutex
);
4733 static const struct file_operations perf_fops
= {
4734 .llseek
= no_llseek
,
4735 .release
= perf_release
,
4738 .unlocked_ioctl
= perf_ioctl
,
4739 .compat_ioctl
= perf_compat_ioctl
,
4741 .fasync
= perf_fasync
,
4747 * If there's data, ensure we set the poll() state and publish everything
4748 * to user-space before waking everybody up.
4751 void perf_event_wakeup(struct perf_event
*event
)
4753 ring_buffer_wakeup(event
);
4755 if (event
->pending_kill
) {
4756 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
4757 event
->pending_kill
= 0;
4761 static void perf_pending_event(struct irq_work
*entry
)
4763 struct perf_event
*event
= container_of(entry
,
4764 struct perf_event
, pending
);
4767 rctx
= perf_swevent_get_recursion_context();
4769 * If we 'fail' here, that's OK, it means recursion is already disabled
4770 * and we won't recurse 'further'.
4773 if (event
->pending_disable
) {
4774 event
->pending_disable
= 0;
4775 __perf_event_disable(event
);
4778 if (event
->pending_wakeup
) {
4779 event
->pending_wakeup
= 0;
4780 perf_event_wakeup(event
);
4784 perf_swevent_put_recursion_context(rctx
);
4788 * We assume there is only KVM supporting the callbacks.
4789 * Later on, we might change it to a list if there is
4790 * another virtualization implementation supporting the callbacks.
4792 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4794 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4796 perf_guest_cbs
= cbs
;
4799 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4801 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4803 perf_guest_cbs
= NULL
;
4806 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4809 perf_output_sample_regs(struct perf_output_handle
*handle
,
4810 struct pt_regs
*regs
, u64 mask
)
4814 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4815 sizeof(mask
) * BITS_PER_BYTE
) {
4818 val
= perf_reg_value(regs
, bit
);
4819 perf_output_put(handle
, val
);
4823 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4824 struct pt_regs
*regs
,
4825 struct pt_regs
*regs_user_copy
)
4827 if (user_mode(regs
)) {
4828 regs_user
->abi
= perf_reg_abi(current
);
4829 regs_user
->regs
= regs
;
4830 } else if (current
->mm
) {
4831 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4833 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
4834 regs_user
->regs
= NULL
;
4838 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
4839 struct pt_regs
*regs
)
4841 regs_intr
->regs
= regs
;
4842 regs_intr
->abi
= perf_reg_abi(current
);
4847 * Get remaining task size from user stack pointer.
4849 * It'd be better to take stack vma map and limit this more
4850 * precisly, but there's no way to get it safely under interrupt,
4851 * so using TASK_SIZE as limit.
4853 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4855 unsigned long addr
= perf_user_stack_pointer(regs
);
4857 if (!addr
|| addr
>= TASK_SIZE
)
4860 return TASK_SIZE
- addr
;
4864 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
4865 struct pt_regs
*regs
)
4869 /* No regs, no stack pointer, no dump. */
4874 * Check if we fit in with the requested stack size into the:
4876 * If we don't, we limit the size to the TASK_SIZE.
4878 * - remaining sample size
4879 * If we don't, we customize the stack size to
4880 * fit in to the remaining sample size.
4883 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
4884 stack_size
= min(stack_size
, (u16
) task_size
);
4886 /* Current header size plus static size and dynamic size. */
4887 header_size
+= 2 * sizeof(u64
);
4889 /* Do we fit in with the current stack dump size? */
4890 if ((u16
) (header_size
+ stack_size
) < header_size
) {
4892 * If we overflow the maximum size for the sample,
4893 * we customize the stack dump size to fit in.
4895 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
4896 stack_size
= round_up(stack_size
, sizeof(u64
));
4903 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
4904 struct pt_regs
*regs
)
4906 /* Case of a kernel thread, nothing to dump */
4909 perf_output_put(handle
, size
);
4918 * - the size requested by user or the best one we can fit
4919 * in to the sample max size
4921 * - user stack dump data
4923 * - the actual dumped size
4927 perf_output_put(handle
, dump_size
);
4930 sp
= perf_user_stack_pointer(regs
);
4931 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
4932 dyn_size
= dump_size
- rem
;
4934 perf_output_skip(handle
, rem
);
4937 perf_output_put(handle
, dyn_size
);
4941 static void __perf_event_header__init_id(struct perf_event_header
*header
,
4942 struct perf_sample_data
*data
,
4943 struct perf_event
*event
)
4945 u64 sample_type
= event
->attr
.sample_type
;
4947 data
->type
= sample_type
;
4948 header
->size
+= event
->id_header_size
;
4950 if (sample_type
& PERF_SAMPLE_TID
) {
4951 /* namespace issues */
4952 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4953 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4956 if (sample_type
& PERF_SAMPLE_TIME
)
4957 data
->time
= perf_event_clock(event
);
4959 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
4960 data
->id
= primary_event_id(event
);
4962 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4963 data
->stream_id
= event
->id
;
4965 if (sample_type
& PERF_SAMPLE_CPU
) {
4966 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4967 data
->cpu_entry
.reserved
= 0;
4971 void perf_event_header__init_id(struct perf_event_header
*header
,
4972 struct perf_sample_data
*data
,
4973 struct perf_event
*event
)
4975 if (event
->attr
.sample_id_all
)
4976 __perf_event_header__init_id(header
, data
, event
);
4979 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4980 struct perf_sample_data
*data
)
4982 u64 sample_type
= data
->type
;
4984 if (sample_type
& PERF_SAMPLE_TID
)
4985 perf_output_put(handle
, data
->tid_entry
);
4987 if (sample_type
& PERF_SAMPLE_TIME
)
4988 perf_output_put(handle
, data
->time
);
4990 if (sample_type
& PERF_SAMPLE_ID
)
4991 perf_output_put(handle
, data
->id
);
4993 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4994 perf_output_put(handle
, data
->stream_id
);
4996 if (sample_type
& PERF_SAMPLE_CPU
)
4997 perf_output_put(handle
, data
->cpu_entry
);
4999 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5000 perf_output_put(handle
, data
->id
);
5003 void perf_event__output_id_sample(struct perf_event
*event
,
5004 struct perf_output_handle
*handle
,
5005 struct perf_sample_data
*sample
)
5007 if (event
->attr
.sample_id_all
)
5008 __perf_event__output_id_sample(handle
, sample
);
5011 static void perf_output_read_one(struct perf_output_handle
*handle
,
5012 struct perf_event
*event
,
5013 u64 enabled
, u64 running
)
5015 u64 read_format
= event
->attr
.read_format
;
5019 values
[n
++] = perf_event_count(event
);
5020 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5021 values
[n
++] = enabled
+
5022 atomic64_read(&event
->child_total_time_enabled
);
5024 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5025 values
[n
++] = running
+
5026 atomic64_read(&event
->child_total_time_running
);
5028 if (read_format
& PERF_FORMAT_ID
)
5029 values
[n
++] = primary_event_id(event
);
5031 __output_copy(handle
, values
, n
* sizeof(u64
));
5035 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5037 static void perf_output_read_group(struct perf_output_handle
*handle
,
5038 struct perf_event
*event
,
5039 u64 enabled
, u64 running
)
5041 struct perf_event
*leader
= event
->group_leader
, *sub
;
5042 u64 read_format
= event
->attr
.read_format
;
5046 values
[n
++] = 1 + leader
->nr_siblings
;
5048 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5049 values
[n
++] = enabled
;
5051 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5052 values
[n
++] = running
;
5054 if (leader
!= event
)
5055 leader
->pmu
->read(leader
);
5057 values
[n
++] = perf_event_count(leader
);
5058 if (read_format
& PERF_FORMAT_ID
)
5059 values
[n
++] = primary_event_id(leader
);
5061 __output_copy(handle
, values
, n
* sizeof(u64
));
5063 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5066 if ((sub
!= event
) &&
5067 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5068 sub
->pmu
->read(sub
);
5070 values
[n
++] = perf_event_count(sub
);
5071 if (read_format
& PERF_FORMAT_ID
)
5072 values
[n
++] = primary_event_id(sub
);
5074 __output_copy(handle
, values
, n
* sizeof(u64
));
5078 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5079 PERF_FORMAT_TOTAL_TIME_RUNNING)
5081 static void perf_output_read(struct perf_output_handle
*handle
,
5082 struct perf_event
*event
)
5084 u64 enabled
= 0, running
= 0, now
;
5085 u64 read_format
= event
->attr
.read_format
;
5088 * compute total_time_enabled, total_time_running
5089 * based on snapshot values taken when the event
5090 * was last scheduled in.
5092 * we cannot simply called update_context_time()
5093 * because of locking issue as we are called in
5096 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5097 calc_timer_values(event
, &now
, &enabled
, &running
);
5099 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5100 perf_output_read_group(handle
, event
, enabled
, running
);
5102 perf_output_read_one(handle
, event
, enabled
, running
);
5105 void perf_output_sample(struct perf_output_handle
*handle
,
5106 struct perf_event_header
*header
,
5107 struct perf_sample_data
*data
,
5108 struct perf_event
*event
)
5110 u64 sample_type
= data
->type
;
5112 perf_output_put(handle
, *header
);
5114 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5115 perf_output_put(handle
, data
->id
);
5117 if (sample_type
& PERF_SAMPLE_IP
)
5118 perf_output_put(handle
, data
->ip
);
5120 if (sample_type
& PERF_SAMPLE_TID
)
5121 perf_output_put(handle
, data
->tid_entry
);
5123 if (sample_type
& PERF_SAMPLE_TIME
)
5124 perf_output_put(handle
, data
->time
);
5126 if (sample_type
& PERF_SAMPLE_ADDR
)
5127 perf_output_put(handle
, data
->addr
);
5129 if (sample_type
& PERF_SAMPLE_ID
)
5130 perf_output_put(handle
, data
->id
);
5132 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5133 perf_output_put(handle
, data
->stream_id
);
5135 if (sample_type
& PERF_SAMPLE_CPU
)
5136 perf_output_put(handle
, data
->cpu_entry
);
5138 if (sample_type
& PERF_SAMPLE_PERIOD
)
5139 perf_output_put(handle
, data
->period
);
5141 if (sample_type
& PERF_SAMPLE_READ
)
5142 perf_output_read(handle
, event
);
5144 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5145 if (data
->callchain
) {
5148 if (data
->callchain
)
5149 size
+= data
->callchain
->nr
;
5151 size
*= sizeof(u64
);
5153 __output_copy(handle
, data
->callchain
, size
);
5156 perf_output_put(handle
, nr
);
5160 if (sample_type
& PERF_SAMPLE_RAW
) {
5162 perf_output_put(handle
, data
->raw
->size
);
5163 __output_copy(handle
, data
->raw
->data
,
5170 .size
= sizeof(u32
),
5173 perf_output_put(handle
, raw
);
5177 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5178 if (data
->br_stack
) {
5181 size
= data
->br_stack
->nr
5182 * sizeof(struct perf_branch_entry
);
5184 perf_output_put(handle
, data
->br_stack
->nr
);
5185 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5188 * we always store at least the value of nr
5191 perf_output_put(handle
, nr
);
5195 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5196 u64 abi
= data
->regs_user
.abi
;
5199 * If there are no regs to dump, notice it through
5200 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5202 perf_output_put(handle
, abi
);
5205 u64 mask
= event
->attr
.sample_regs_user
;
5206 perf_output_sample_regs(handle
,
5207 data
->regs_user
.regs
,
5212 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5213 perf_output_sample_ustack(handle
,
5214 data
->stack_user_size
,
5215 data
->regs_user
.regs
);
5218 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5219 perf_output_put(handle
, data
->weight
);
5221 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5222 perf_output_put(handle
, data
->data_src
.val
);
5224 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5225 perf_output_put(handle
, data
->txn
);
5227 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5228 u64 abi
= data
->regs_intr
.abi
;
5230 * If there are no regs to dump, notice it through
5231 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5233 perf_output_put(handle
, abi
);
5236 u64 mask
= event
->attr
.sample_regs_intr
;
5238 perf_output_sample_regs(handle
,
5239 data
->regs_intr
.regs
,
5244 if (!event
->attr
.watermark
) {
5245 int wakeup_events
= event
->attr
.wakeup_events
;
5247 if (wakeup_events
) {
5248 struct ring_buffer
*rb
= handle
->rb
;
5249 int events
= local_inc_return(&rb
->events
);
5251 if (events
>= wakeup_events
) {
5252 local_sub(wakeup_events
, &rb
->events
);
5253 local_inc(&rb
->wakeup
);
5259 void perf_prepare_sample(struct perf_event_header
*header
,
5260 struct perf_sample_data
*data
,
5261 struct perf_event
*event
,
5262 struct pt_regs
*regs
)
5264 u64 sample_type
= event
->attr
.sample_type
;
5266 header
->type
= PERF_RECORD_SAMPLE
;
5267 header
->size
= sizeof(*header
) + event
->header_size
;
5270 header
->misc
|= perf_misc_flags(regs
);
5272 __perf_event_header__init_id(header
, data
, event
);
5274 if (sample_type
& PERF_SAMPLE_IP
)
5275 data
->ip
= perf_instruction_pointer(regs
);
5277 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5280 data
->callchain
= perf_callchain(event
, regs
);
5282 if (data
->callchain
)
5283 size
+= data
->callchain
->nr
;
5285 header
->size
+= size
* sizeof(u64
);
5288 if (sample_type
& PERF_SAMPLE_RAW
) {
5289 int size
= sizeof(u32
);
5292 size
+= data
->raw
->size
;
5294 size
+= sizeof(u32
);
5296 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
5297 header
->size
+= size
;
5300 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5301 int size
= sizeof(u64
); /* nr */
5302 if (data
->br_stack
) {
5303 size
+= data
->br_stack
->nr
5304 * sizeof(struct perf_branch_entry
);
5306 header
->size
+= size
;
5309 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5310 perf_sample_regs_user(&data
->regs_user
, regs
,
5311 &data
->regs_user_copy
);
5313 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5314 /* regs dump ABI info */
5315 int size
= sizeof(u64
);
5317 if (data
->regs_user
.regs
) {
5318 u64 mask
= event
->attr
.sample_regs_user
;
5319 size
+= hweight64(mask
) * sizeof(u64
);
5322 header
->size
+= size
;
5325 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5327 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5328 * processed as the last one or have additional check added
5329 * in case new sample type is added, because we could eat
5330 * up the rest of the sample size.
5332 u16 stack_size
= event
->attr
.sample_stack_user
;
5333 u16 size
= sizeof(u64
);
5335 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5336 data
->regs_user
.regs
);
5339 * If there is something to dump, add space for the dump
5340 * itself and for the field that tells the dynamic size,
5341 * which is how many have been actually dumped.
5344 size
+= sizeof(u64
) + stack_size
;
5346 data
->stack_user_size
= stack_size
;
5347 header
->size
+= size
;
5350 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5351 /* regs dump ABI info */
5352 int size
= sizeof(u64
);
5354 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5356 if (data
->regs_intr
.regs
) {
5357 u64 mask
= event
->attr
.sample_regs_intr
;
5359 size
+= hweight64(mask
) * sizeof(u64
);
5362 header
->size
+= size
;
5366 void perf_event_output(struct perf_event
*event
,
5367 struct perf_sample_data
*data
,
5368 struct pt_regs
*regs
)
5370 struct perf_output_handle handle
;
5371 struct perf_event_header header
;
5373 /* protect the callchain buffers */
5376 perf_prepare_sample(&header
, data
, event
, regs
);
5378 if (perf_output_begin(&handle
, event
, header
.size
))
5381 perf_output_sample(&handle
, &header
, data
, event
);
5383 perf_output_end(&handle
);
5393 struct perf_read_event
{
5394 struct perf_event_header header
;
5401 perf_event_read_event(struct perf_event
*event
,
5402 struct task_struct
*task
)
5404 struct perf_output_handle handle
;
5405 struct perf_sample_data sample
;
5406 struct perf_read_event read_event
= {
5408 .type
= PERF_RECORD_READ
,
5410 .size
= sizeof(read_event
) + event
->read_size
,
5412 .pid
= perf_event_pid(event
, task
),
5413 .tid
= perf_event_tid(event
, task
),
5417 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5418 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5422 perf_output_put(&handle
, read_event
);
5423 perf_output_read(&handle
, event
);
5424 perf_event__output_id_sample(event
, &handle
, &sample
);
5426 perf_output_end(&handle
);
5429 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5432 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5433 perf_event_aux_output_cb output
,
5436 struct perf_event
*event
;
5438 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5439 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5441 if (!event_filter_match(event
))
5443 output(event
, data
);
5448 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5449 struct perf_event_context
*task_ctx
)
5451 struct perf_cpu_context
*cpuctx
;
5452 struct perf_event_context
*ctx
;
5457 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5458 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5459 if (cpuctx
->unique_pmu
!= pmu
)
5461 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5464 ctxn
= pmu
->task_ctx_nr
;
5467 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5469 perf_event_aux_ctx(ctx
, output
, data
);
5471 put_cpu_ptr(pmu
->pmu_cpu_context
);
5476 perf_event_aux_ctx(task_ctx
, output
, data
);
5483 * task tracking -- fork/exit
5485 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5488 struct perf_task_event
{
5489 struct task_struct
*task
;
5490 struct perf_event_context
*task_ctx
;
5493 struct perf_event_header header
;
5503 static int perf_event_task_match(struct perf_event
*event
)
5505 return event
->attr
.comm
|| event
->attr
.mmap
||
5506 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5510 static void perf_event_task_output(struct perf_event
*event
,
5513 struct perf_task_event
*task_event
= data
;
5514 struct perf_output_handle handle
;
5515 struct perf_sample_data sample
;
5516 struct task_struct
*task
= task_event
->task
;
5517 int ret
, size
= task_event
->event_id
.header
.size
;
5519 if (!perf_event_task_match(event
))
5522 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5524 ret
= perf_output_begin(&handle
, event
,
5525 task_event
->event_id
.header
.size
);
5529 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5530 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5532 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5533 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5535 task_event
->event_id
.time
= perf_event_clock(event
);
5537 perf_output_put(&handle
, task_event
->event_id
);
5539 perf_event__output_id_sample(event
, &handle
, &sample
);
5541 perf_output_end(&handle
);
5543 task_event
->event_id
.header
.size
= size
;
5546 static void perf_event_task(struct task_struct
*task
,
5547 struct perf_event_context
*task_ctx
,
5550 struct perf_task_event task_event
;
5552 if (!atomic_read(&nr_comm_events
) &&
5553 !atomic_read(&nr_mmap_events
) &&
5554 !atomic_read(&nr_task_events
))
5557 task_event
= (struct perf_task_event
){
5559 .task_ctx
= task_ctx
,
5562 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5564 .size
= sizeof(task_event
.event_id
),
5574 perf_event_aux(perf_event_task_output
,
5579 void perf_event_fork(struct task_struct
*task
)
5581 perf_event_task(task
, NULL
, 1);
5588 struct perf_comm_event
{
5589 struct task_struct
*task
;
5594 struct perf_event_header header
;
5601 static int perf_event_comm_match(struct perf_event
*event
)
5603 return event
->attr
.comm
;
5606 static void perf_event_comm_output(struct perf_event
*event
,
5609 struct perf_comm_event
*comm_event
= data
;
5610 struct perf_output_handle handle
;
5611 struct perf_sample_data sample
;
5612 int size
= comm_event
->event_id
.header
.size
;
5615 if (!perf_event_comm_match(event
))
5618 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5619 ret
= perf_output_begin(&handle
, event
,
5620 comm_event
->event_id
.header
.size
);
5625 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5626 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5628 perf_output_put(&handle
, comm_event
->event_id
);
5629 __output_copy(&handle
, comm_event
->comm
,
5630 comm_event
->comm_size
);
5632 perf_event__output_id_sample(event
, &handle
, &sample
);
5634 perf_output_end(&handle
);
5636 comm_event
->event_id
.header
.size
= size
;
5639 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5641 char comm
[TASK_COMM_LEN
];
5644 memset(comm
, 0, sizeof(comm
));
5645 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5646 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5648 comm_event
->comm
= comm
;
5649 comm_event
->comm_size
= size
;
5651 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5653 perf_event_aux(perf_event_comm_output
,
5658 void perf_event_comm(struct task_struct
*task
, bool exec
)
5660 struct perf_comm_event comm_event
;
5662 if (!atomic_read(&nr_comm_events
))
5665 comm_event
= (struct perf_comm_event
){
5671 .type
= PERF_RECORD_COMM
,
5672 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5680 perf_event_comm_event(&comm_event
);
5687 struct perf_mmap_event
{
5688 struct vm_area_struct
*vma
;
5690 const char *file_name
;
5698 struct perf_event_header header
;
5708 static int perf_event_mmap_match(struct perf_event
*event
,
5711 struct perf_mmap_event
*mmap_event
= data
;
5712 struct vm_area_struct
*vma
= mmap_event
->vma
;
5713 int executable
= vma
->vm_flags
& VM_EXEC
;
5715 return (!executable
&& event
->attr
.mmap_data
) ||
5716 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5719 static void perf_event_mmap_output(struct perf_event
*event
,
5722 struct perf_mmap_event
*mmap_event
= data
;
5723 struct perf_output_handle handle
;
5724 struct perf_sample_data sample
;
5725 int size
= mmap_event
->event_id
.header
.size
;
5728 if (!perf_event_mmap_match(event
, data
))
5731 if (event
->attr
.mmap2
) {
5732 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5733 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5734 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5735 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5736 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5737 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5738 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5741 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5742 ret
= perf_output_begin(&handle
, event
,
5743 mmap_event
->event_id
.header
.size
);
5747 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5748 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5750 perf_output_put(&handle
, mmap_event
->event_id
);
5752 if (event
->attr
.mmap2
) {
5753 perf_output_put(&handle
, mmap_event
->maj
);
5754 perf_output_put(&handle
, mmap_event
->min
);
5755 perf_output_put(&handle
, mmap_event
->ino
);
5756 perf_output_put(&handle
, mmap_event
->ino_generation
);
5757 perf_output_put(&handle
, mmap_event
->prot
);
5758 perf_output_put(&handle
, mmap_event
->flags
);
5761 __output_copy(&handle
, mmap_event
->file_name
,
5762 mmap_event
->file_size
);
5764 perf_event__output_id_sample(event
, &handle
, &sample
);
5766 perf_output_end(&handle
);
5768 mmap_event
->event_id
.header
.size
= size
;
5771 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5773 struct vm_area_struct
*vma
= mmap_event
->vma
;
5774 struct file
*file
= vma
->vm_file
;
5775 int maj
= 0, min
= 0;
5776 u64 ino
= 0, gen
= 0;
5777 u32 prot
= 0, flags
= 0;
5784 struct inode
*inode
;
5787 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5793 * d_path() works from the end of the rb backwards, so we
5794 * need to add enough zero bytes after the string to handle
5795 * the 64bit alignment we do later.
5797 name
= d_path(&file
->f_path
, buf
, PATH_MAX
- sizeof(u64
));
5802 inode
= file_inode(vma
->vm_file
);
5803 dev
= inode
->i_sb
->s_dev
;
5805 gen
= inode
->i_generation
;
5809 if (vma
->vm_flags
& VM_READ
)
5811 if (vma
->vm_flags
& VM_WRITE
)
5813 if (vma
->vm_flags
& VM_EXEC
)
5816 if (vma
->vm_flags
& VM_MAYSHARE
)
5819 flags
= MAP_PRIVATE
;
5821 if (vma
->vm_flags
& VM_DENYWRITE
)
5822 flags
|= MAP_DENYWRITE
;
5823 if (vma
->vm_flags
& VM_MAYEXEC
)
5824 flags
|= MAP_EXECUTABLE
;
5825 if (vma
->vm_flags
& VM_LOCKED
)
5826 flags
|= MAP_LOCKED
;
5827 if (vma
->vm_flags
& VM_HUGETLB
)
5828 flags
|= MAP_HUGETLB
;
5832 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
5833 name
= (char *) vma
->vm_ops
->name(vma
);
5838 name
= (char *)arch_vma_name(vma
);
5842 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
5843 vma
->vm_end
>= vma
->vm_mm
->brk
) {
5847 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
5848 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
5858 strlcpy(tmp
, name
, sizeof(tmp
));
5862 * Since our buffer works in 8 byte units we need to align our string
5863 * size to a multiple of 8. However, we must guarantee the tail end is
5864 * zero'd out to avoid leaking random bits to userspace.
5866 size
= strlen(name
)+1;
5867 while (!IS_ALIGNED(size
, sizeof(u64
)))
5868 name
[size
++] = '\0';
5870 mmap_event
->file_name
= name
;
5871 mmap_event
->file_size
= size
;
5872 mmap_event
->maj
= maj
;
5873 mmap_event
->min
= min
;
5874 mmap_event
->ino
= ino
;
5875 mmap_event
->ino_generation
= gen
;
5876 mmap_event
->prot
= prot
;
5877 mmap_event
->flags
= flags
;
5879 if (!(vma
->vm_flags
& VM_EXEC
))
5880 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
5882 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
5884 perf_event_aux(perf_event_mmap_output
,
5891 void perf_event_mmap(struct vm_area_struct
*vma
)
5893 struct perf_mmap_event mmap_event
;
5895 if (!atomic_read(&nr_mmap_events
))
5898 mmap_event
= (struct perf_mmap_event
){
5904 .type
= PERF_RECORD_MMAP
,
5905 .misc
= PERF_RECORD_MISC_USER
,
5910 .start
= vma
->vm_start
,
5911 .len
= vma
->vm_end
- vma
->vm_start
,
5912 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
5914 /* .maj (attr_mmap2 only) */
5915 /* .min (attr_mmap2 only) */
5916 /* .ino (attr_mmap2 only) */
5917 /* .ino_generation (attr_mmap2 only) */
5918 /* .prot (attr_mmap2 only) */
5919 /* .flags (attr_mmap2 only) */
5922 perf_event_mmap_event(&mmap_event
);
5925 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
5926 unsigned long size
, u64 flags
)
5928 struct perf_output_handle handle
;
5929 struct perf_sample_data sample
;
5930 struct perf_aux_event
{
5931 struct perf_event_header header
;
5937 .type
= PERF_RECORD_AUX
,
5939 .size
= sizeof(rec
),
5947 perf_event_header__init_id(&rec
.header
, &sample
, event
);
5948 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
5953 perf_output_put(&handle
, rec
);
5954 perf_event__output_id_sample(event
, &handle
, &sample
);
5956 perf_output_end(&handle
);
5960 * Lost/dropped samples logging
5962 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
5964 struct perf_output_handle handle
;
5965 struct perf_sample_data sample
;
5969 struct perf_event_header header
;
5971 } lost_samples_event
= {
5973 .type
= PERF_RECORD_LOST_SAMPLES
,
5975 .size
= sizeof(lost_samples_event
),
5980 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
5982 ret
= perf_output_begin(&handle
, event
,
5983 lost_samples_event
.header
.size
);
5987 perf_output_put(&handle
, lost_samples_event
);
5988 perf_event__output_id_sample(event
, &handle
, &sample
);
5989 perf_output_end(&handle
);
5993 * IRQ throttle logging
5996 static void perf_log_throttle(struct perf_event
*event
, int enable
)
5998 struct perf_output_handle handle
;
5999 struct perf_sample_data sample
;
6003 struct perf_event_header header
;
6007 } throttle_event
= {
6009 .type
= PERF_RECORD_THROTTLE
,
6011 .size
= sizeof(throttle_event
),
6013 .time
= perf_event_clock(event
),
6014 .id
= primary_event_id(event
),
6015 .stream_id
= event
->id
,
6019 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6021 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6023 ret
= perf_output_begin(&handle
, event
,
6024 throttle_event
.header
.size
);
6028 perf_output_put(&handle
, throttle_event
);
6029 perf_event__output_id_sample(event
, &handle
, &sample
);
6030 perf_output_end(&handle
);
6033 static void perf_log_itrace_start(struct perf_event
*event
)
6035 struct perf_output_handle handle
;
6036 struct perf_sample_data sample
;
6037 struct perf_aux_event
{
6038 struct perf_event_header header
;
6045 event
= event
->parent
;
6047 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6048 event
->hw
.itrace_started
)
6051 event
->hw
.itrace_started
= 1;
6053 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6054 rec
.header
.misc
= 0;
6055 rec
.header
.size
= sizeof(rec
);
6056 rec
.pid
= perf_event_pid(event
, current
);
6057 rec
.tid
= perf_event_tid(event
, current
);
6059 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6060 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6065 perf_output_put(&handle
, rec
);
6066 perf_event__output_id_sample(event
, &handle
, &sample
);
6068 perf_output_end(&handle
);
6072 * Generic event overflow handling, sampling.
6075 static int __perf_event_overflow(struct perf_event
*event
,
6076 int throttle
, struct perf_sample_data
*data
,
6077 struct pt_regs
*regs
)
6079 int events
= atomic_read(&event
->event_limit
);
6080 struct hw_perf_event
*hwc
= &event
->hw
;
6085 * Non-sampling counters might still use the PMI to fold short
6086 * hardware counters, ignore those.
6088 if (unlikely(!is_sampling_event(event
)))
6091 seq
= __this_cpu_read(perf_throttled_seq
);
6092 if (seq
!= hwc
->interrupts_seq
) {
6093 hwc
->interrupts_seq
= seq
;
6094 hwc
->interrupts
= 1;
6097 if (unlikely(throttle
6098 && hwc
->interrupts
>= max_samples_per_tick
)) {
6099 __this_cpu_inc(perf_throttled_count
);
6100 hwc
->interrupts
= MAX_INTERRUPTS
;
6101 perf_log_throttle(event
, 0);
6102 tick_nohz_full_kick();
6107 if (event
->attr
.freq
) {
6108 u64 now
= perf_clock();
6109 s64 delta
= now
- hwc
->freq_time_stamp
;
6111 hwc
->freq_time_stamp
= now
;
6113 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6114 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6118 * XXX event_limit might not quite work as expected on inherited
6122 event
->pending_kill
= POLL_IN
;
6123 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6125 event
->pending_kill
= POLL_HUP
;
6126 event
->pending_disable
= 1;
6127 irq_work_queue(&event
->pending
);
6130 if (event
->overflow_handler
)
6131 event
->overflow_handler(event
, data
, regs
);
6133 perf_event_output(event
, data
, regs
);
6135 if (event
->fasync
&& event
->pending_kill
) {
6136 event
->pending_wakeup
= 1;
6137 irq_work_queue(&event
->pending
);
6143 int perf_event_overflow(struct perf_event
*event
,
6144 struct perf_sample_data
*data
,
6145 struct pt_regs
*regs
)
6147 return __perf_event_overflow(event
, 1, data
, regs
);
6151 * Generic software event infrastructure
6154 struct swevent_htable
{
6155 struct swevent_hlist
*swevent_hlist
;
6156 struct mutex hlist_mutex
;
6159 /* Recursion avoidance in each contexts */
6160 int recursion
[PERF_NR_CONTEXTS
];
6162 /* Keeps track of cpu being initialized/exited */
6166 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6169 * We directly increment event->count and keep a second value in
6170 * event->hw.period_left to count intervals. This period event
6171 * is kept in the range [-sample_period, 0] so that we can use the
6175 u64
perf_swevent_set_period(struct perf_event
*event
)
6177 struct hw_perf_event
*hwc
= &event
->hw
;
6178 u64 period
= hwc
->last_period
;
6182 hwc
->last_period
= hwc
->sample_period
;
6185 old
= val
= local64_read(&hwc
->period_left
);
6189 nr
= div64_u64(period
+ val
, period
);
6190 offset
= nr
* period
;
6192 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6198 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6199 struct perf_sample_data
*data
,
6200 struct pt_regs
*regs
)
6202 struct hw_perf_event
*hwc
= &event
->hw
;
6206 overflow
= perf_swevent_set_period(event
);
6208 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6211 for (; overflow
; overflow
--) {
6212 if (__perf_event_overflow(event
, throttle
,
6215 * We inhibit the overflow from happening when
6216 * hwc->interrupts == MAX_INTERRUPTS.
6224 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6225 struct perf_sample_data
*data
,
6226 struct pt_regs
*regs
)
6228 struct hw_perf_event
*hwc
= &event
->hw
;
6230 local64_add(nr
, &event
->count
);
6235 if (!is_sampling_event(event
))
6238 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6240 return perf_swevent_overflow(event
, 1, data
, regs
);
6242 data
->period
= event
->hw
.last_period
;
6244 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6245 return perf_swevent_overflow(event
, 1, data
, regs
);
6247 if (local64_add_negative(nr
, &hwc
->period_left
))
6250 perf_swevent_overflow(event
, 0, data
, regs
);
6253 static int perf_exclude_event(struct perf_event
*event
,
6254 struct pt_regs
*regs
)
6256 if (event
->hw
.state
& PERF_HES_STOPPED
)
6260 if (event
->attr
.exclude_user
&& user_mode(regs
))
6263 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6270 static int perf_swevent_match(struct perf_event
*event
,
6271 enum perf_type_id type
,
6273 struct perf_sample_data
*data
,
6274 struct pt_regs
*regs
)
6276 if (event
->attr
.type
!= type
)
6279 if (event
->attr
.config
!= event_id
)
6282 if (perf_exclude_event(event
, regs
))
6288 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6290 u64 val
= event_id
| (type
<< 32);
6292 return hash_64(val
, SWEVENT_HLIST_BITS
);
6295 static inline struct hlist_head
*
6296 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6298 u64 hash
= swevent_hash(type
, event_id
);
6300 return &hlist
->heads
[hash
];
6303 /* For the read side: events when they trigger */
6304 static inline struct hlist_head
*
6305 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6307 struct swevent_hlist
*hlist
;
6309 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6313 return __find_swevent_head(hlist
, type
, event_id
);
6316 /* For the event head insertion and removal in the hlist */
6317 static inline struct hlist_head
*
6318 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6320 struct swevent_hlist
*hlist
;
6321 u32 event_id
= event
->attr
.config
;
6322 u64 type
= event
->attr
.type
;
6325 * Event scheduling is always serialized against hlist allocation
6326 * and release. Which makes the protected version suitable here.
6327 * The context lock guarantees that.
6329 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6330 lockdep_is_held(&event
->ctx
->lock
));
6334 return __find_swevent_head(hlist
, type
, event_id
);
6337 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6339 struct perf_sample_data
*data
,
6340 struct pt_regs
*regs
)
6342 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6343 struct perf_event
*event
;
6344 struct hlist_head
*head
;
6347 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6351 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6352 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6353 perf_swevent_event(event
, nr
, data
, regs
);
6359 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6361 int perf_swevent_get_recursion_context(void)
6363 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6365 return get_recursion_context(swhash
->recursion
);
6367 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6369 inline void perf_swevent_put_recursion_context(int rctx
)
6371 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6373 put_recursion_context(swhash
->recursion
, rctx
);
6376 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6378 struct perf_sample_data data
;
6380 if (WARN_ON_ONCE(!regs
))
6383 perf_sample_data_init(&data
, addr
, 0);
6384 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6387 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6391 preempt_disable_notrace();
6392 rctx
= perf_swevent_get_recursion_context();
6393 if (unlikely(rctx
< 0))
6396 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6398 perf_swevent_put_recursion_context(rctx
);
6400 preempt_enable_notrace();
6403 static void perf_swevent_read(struct perf_event
*event
)
6407 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6409 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6410 struct hw_perf_event
*hwc
= &event
->hw
;
6411 struct hlist_head
*head
;
6413 if (is_sampling_event(event
)) {
6414 hwc
->last_period
= hwc
->sample_period
;
6415 perf_swevent_set_period(event
);
6418 hwc
->state
= !(flags
& PERF_EF_START
);
6420 head
= find_swevent_head(swhash
, event
);
6423 * We can race with cpu hotplug code. Do not
6424 * WARN if the cpu just got unplugged.
6426 WARN_ON_ONCE(swhash
->online
);
6430 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6431 perf_event_update_userpage(event
);
6436 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6438 hlist_del_rcu(&event
->hlist_entry
);
6441 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6443 event
->hw
.state
= 0;
6446 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6448 event
->hw
.state
= PERF_HES_STOPPED
;
6451 /* Deref the hlist from the update side */
6452 static inline struct swevent_hlist
*
6453 swevent_hlist_deref(struct swevent_htable
*swhash
)
6455 return rcu_dereference_protected(swhash
->swevent_hlist
,
6456 lockdep_is_held(&swhash
->hlist_mutex
));
6459 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6461 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6466 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6467 kfree_rcu(hlist
, rcu_head
);
6470 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6472 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6474 mutex_lock(&swhash
->hlist_mutex
);
6476 if (!--swhash
->hlist_refcount
)
6477 swevent_hlist_release(swhash
);
6479 mutex_unlock(&swhash
->hlist_mutex
);
6482 static void swevent_hlist_put(struct perf_event
*event
)
6486 for_each_possible_cpu(cpu
)
6487 swevent_hlist_put_cpu(event
, cpu
);
6490 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6492 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6495 mutex_lock(&swhash
->hlist_mutex
);
6497 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6498 struct swevent_hlist
*hlist
;
6500 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6505 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6507 swhash
->hlist_refcount
++;
6509 mutex_unlock(&swhash
->hlist_mutex
);
6514 static int swevent_hlist_get(struct perf_event
*event
)
6517 int cpu
, failed_cpu
;
6520 for_each_possible_cpu(cpu
) {
6521 err
= swevent_hlist_get_cpu(event
, cpu
);
6531 for_each_possible_cpu(cpu
) {
6532 if (cpu
== failed_cpu
)
6534 swevent_hlist_put_cpu(event
, cpu
);
6541 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6543 static void sw_perf_event_destroy(struct perf_event
*event
)
6545 u64 event_id
= event
->attr
.config
;
6547 WARN_ON(event
->parent
);
6549 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6550 swevent_hlist_put(event
);
6553 static int perf_swevent_init(struct perf_event
*event
)
6555 u64 event_id
= event
->attr
.config
;
6557 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6561 * no branch sampling for software events
6563 if (has_branch_stack(event
))
6567 case PERF_COUNT_SW_CPU_CLOCK
:
6568 case PERF_COUNT_SW_TASK_CLOCK
:
6575 if (event_id
>= PERF_COUNT_SW_MAX
)
6578 if (!event
->parent
) {
6581 err
= swevent_hlist_get(event
);
6585 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6586 event
->destroy
= sw_perf_event_destroy
;
6592 static struct pmu perf_swevent
= {
6593 .task_ctx_nr
= perf_sw_context
,
6595 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6597 .event_init
= perf_swevent_init
,
6598 .add
= perf_swevent_add
,
6599 .del
= perf_swevent_del
,
6600 .start
= perf_swevent_start
,
6601 .stop
= perf_swevent_stop
,
6602 .read
= perf_swevent_read
,
6605 #ifdef CONFIG_EVENT_TRACING
6607 static int perf_tp_filter_match(struct perf_event
*event
,
6608 struct perf_sample_data
*data
)
6610 void *record
= data
->raw
->data
;
6612 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6617 static int perf_tp_event_match(struct perf_event
*event
,
6618 struct perf_sample_data
*data
,
6619 struct pt_regs
*regs
)
6621 if (event
->hw
.state
& PERF_HES_STOPPED
)
6624 * All tracepoints are from kernel-space.
6626 if (event
->attr
.exclude_kernel
)
6629 if (!perf_tp_filter_match(event
, data
))
6635 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6636 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6637 struct task_struct
*task
)
6639 struct perf_sample_data data
;
6640 struct perf_event
*event
;
6642 struct perf_raw_record raw
= {
6647 perf_sample_data_init(&data
, addr
, 0);
6650 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6651 if (perf_tp_event_match(event
, &data
, regs
))
6652 perf_swevent_event(event
, count
, &data
, regs
);
6656 * If we got specified a target task, also iterate its context and
6657 * deliver this event there too.
6659 if (task
&& task
!= current
) {
6660 struct perf_event_context
*ctx
;
6661 struct trace_entry
*entry
= record
;
6664 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6668 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6669 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6671 if (event
->attr
.config
!= entry
->type
)
6673 if (perf_tp_event_match(event
, &data
, regs
))
6674 perf_swevent_event(event
, count
, &data
, regs
);
6680 perf_swevent_put_recursion_context(rctx
);
6682 EXPORT_SYMBOL_GPL(perf_tp_event
);
6684 static void tp_perf_event_destroy(struct perf_event
*event
)
6686 perf_trace_destroy(event
);
6689 static int perf_tp_event_init(struct perf_event
*event
)
6693 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6697 * no branch sampling for tracepoint events
6699 if (has_branch_stack(event
))
6702 err
= perf_trace_init(event
);
6706 event
->destroy
= tp_perf_event_destroy
;
6711 static struct pmu perf_tracepoint
= {
6712 .task_ctx_nr
= perf_sw_context
,
6714 .event_init
= perf_tp_event_init
,
6715 .add
= perf_trace_add
,
6716 .del
= perf_trace_del
,
6717 .start
= perf_swevent_start
,
6718 .stop
= perf_swevent_stop
,
6719 .read
= perf_swevent_read
,
6722 static inline void perf_tp_register(void)
6724 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6727 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6732 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6735 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6736 if (IS_ERR(filter_str
))
6737 return PTR_ERR(filter_str
);
6739 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
6745 static void perf_event_free_filter(struct perf_event
*event
)
6747 ftrace_profile_free_filter(event
);
6750 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
6752 struct bpf_prog
*prog
;
6754 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6757 if (event
->tp_event
->prog
)
6760 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_KPROBE
))
6761 /* bpf programs can only be attached to kprobes */
6764 prog
= bpf_prog_get(prog_fd
);
6766 return PTR_ERR(prog
);
6768 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
6769 /* valid fd, but invalid bpf program type */
6774 event
->tp_event
->prog
= prog
;
6779 static void perf_event_free_bpf_prog(struct perf_event
*event
)
6781 struct bpf_prog
*prog
;
6783 if (!event
->tp_event
)
6786 prog
= event
->tp_event
->prog
;
6788 event
->tp_event
->prog
= NULL
;
6795 static inline void perf_tp_register(void)
6799 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6804 static void perf_event_free_filter(struct perf_event
*event
)
6808 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
6813 static void perf_event_free_bpf_prog(struct perf_event
*event
)
6816 #endif /* CONFIG_EVENT_TRACING */
6818 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6819 void perf_bp_event(struct perf_event
*bp
, void *data
)
6821 struct perf_sample_data sample
;
6822 struct pt_regs
*regs
= data
;
6824 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
6826 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
6827 perf_swevent_event(bp
, 1, &sample
, regs
);
6832 * hrtimer based swevent callback
6835 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
6837 enum hrtimer_restart ret
= HRTIMER_RESTART
;
6838 struct perf_sample_data data
;
6839 struct pt_regs
*regs
;
6840 struct perf_event
*event
;
6843 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
6845 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
6846 return HRTIMER_NORESTART
;
6848 event
->pmu
->read(event
);
6850 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
6851 regs
= get_irq_regs();
6853 if (regs
&& !perf_exclude_event(event
, regs
)) {
6854 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
6855 if (__perf_event_overflow(event
, 1, &data
, regs
))
6856 ret
= HRTIMER_NORESTART
;
6859 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
6860 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
6865 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
6867 struct hw_perf_event
*hwc
= &event
->hw
;
6870 if (!is_sampling_event(event
))
6873 period
= local64_read(&hwc
->period_left
);
6878 local64_set(&hwc
->period_left
, 0);
6880 period
= max_t(u64
, 10000, hwc
->sample_period
);
6882 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
6883 HRTIMER_MODE_REL_PINNED
);
6886 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
6888 struct hw_perf_event
*hwc
= &event
->hw
;
6890 if (is_sampling_event(event
)) {
6891 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
6892 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
6894 hrtimer_cancel(&hwc
->hrtimer
);
6898 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
6900 struct hw_perf_event
*hwc
= &event
->hw
;
6902 if (!is_sampling_event(event
))
6905 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
6906 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
6909 * Since hrtimers have a fixed rate, we can do a static freq->period
6910 * mapping and avoid the whole period adjust feedback stuff.
6912 if (event
->attr
.freq
) {
6913 long freq
= event
->attr
.sample_freq
;
6915 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
6916 hwc
->sample_period
= event
->attr
.sample_period
;
6917 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6918 hwc
->last_period
= hwc
->sample_period
;
6919 event
->attr
.freq
= 0;
6924 * Software event: cpu wall time clock
6927 static void cpu_clock_event_update(struct perf_event
*event
)
6932 now
= local_clock();
6933 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6934 local64_add(now
- prev
, &event
->count
);
6937 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
6939 local64_set(&event
->hw
.prev_count
, local_clock());
6940 perf_swevent_start_hrtimer(event
);
6943 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
6945 perf_swevent_cancel_hrtimer(event
);
6946 cpu_clock_event_update(event
);
6949 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
6951 if (flags
& PERF_EF_START
)
6952 cpu_clock_event_start(event
, flags
);
6953 perf_event_update_userpage(event
);
6958 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
6960 cpu_clock_event_stop(event
, flags
);
6963 static void cpu_clock_event_read(struct perf_event
*event
)
6965 cpu_clock_event_update(event
);
6968 static int cpu_clock_event_init(struct perf_event
*event
)
6970 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6973 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
6977 * no branch sampling for software events
6979 if (has_branch_stack(event
))
6982 perf_swevent_init_hrtimer(event
);
6987 static struct pmu perf_cpu_clock
= {
6988 .task_ctx_nr
= perf_sw_context
,
6990 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6992 .event_init
= cpu_clock_event_init
,
6993 .add
= cpu_clock_event_add
,
6994 .del
= cpu_clock_event_del
,
6995 .start
= cpu_clock_event_start
,
6996 .stop
= cpu_clock_event_stop
,
6997 .read
= cpu_clock_event_read
,
7001 * Software event: task time clock
7004 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7009 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7011 local64_add(delta
, &event
->count
);
7014 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7016 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7017 perf_swevent_start_hrtimer(event
);
7020 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7022 perf_swevent_cancel_hrtimer(event
);
7023 task_clock_event_update(event
, event
->ctx
->time
);
7026 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7028 if (flags
& PERF_EF_START
)
7029 task_clock_event_start(event
, flags
);
7030 perf_event_update_userpage(event
);
7035 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7037 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7040 static void task_clock_event_read(struct perf_event
*event
)
7042 u64 now
= perf_clock();
7043 u64 delta
= now
- event
->ctx
->timestamp
;
7044 u64 time
= event
->ctx
->time
+ delta
;
7046 task_clock_event_update(event
, time
);
7049 static int task_clock_event_init(struct perf_event
*event
)
7051 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7054 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7058 * no branch sampling for software events
7060 if (has_branch_stack(event
))
7063 perf_swevent_init_hrtimer(event
);
7068 static struct pmu perf_task_clock
= {
7069 .task_ctx_nr
= perf_sw_context
,
7071 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7073 .event_init
= task_clock_event_init
,
7074 .add
= task_clock_event_add
,
7075 .del
= task_clock_event_del
,
7076 .start
= task_clock_event_start
,
7077 .stop
= task_clock_event_stop
,
7078 .read
= task_clock_event_read
,
7081 static void perf_pmu_nop_void(struct pmu
*pmu
)
7085 static int perf_pmu_nop_int(struct pmu
*pmu
)
7090 static void perf_pmu_start_txn(struct pmu
*pmu
)
7092 perf_pmu_disable(pmu
);
7095 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7097 perf_pmu_enable(pmu
);
7101 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7103 perf_pmu_enable(pmu
);
7106 static int perf_event_idx_default(struct perf_event
*event
)
7112 * Ensures all contexts with the same task_ctx_nr have the same
7113 * pmu_cpu_context too.
7115 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7122 list_for_each_entry(pmu
, &pmus
, entry
) {
7123 if (pmu
->task_ctx_nr
== ctxn
)
7124 return pmu
->pmu_cpu_context
;
7130 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7134 for_each_possible_cpu(cpu
) {
7135 struct perf_cpu_context
*cpuctx
;
7137 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7139 if (cpuctx
->unique_pmu
== old_pmu
)
7140 cpuctx
->unique_pmu
= pmu
;
7144 static void free_pmu_context(struct pmu
*pmu
)
7148 mutex_lock(&pmus_lock
);
7150 * Like a real lame refcount.
7152 list_for_each_entry(i
, &pmus
, entry
) {
7153 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7154 update_pmu_context(i
, pmu
);
7159 free_percpu(pmu
->pmu_cpu_context
);
7161 mutex_unlock(&pmus_lock
);
7163 static struct idr pmu_idr
;
7166 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7168 struct pmu
*pmu
= dev_get_drvdata(dev
);
7170 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7172 static DEVICE_ATTR_RO(type
);
7175 perf_event_mux_interval_ms_show(struct device
*dev
,
7176 struct device_attribute
*attr
,
7179 struct pmu
*pmu
= dev_get_drvdata(dev
);
7181 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7184 static DEFINE_MUTEX(mux_interval_mutex
);
7187 perf_event_mux_interval_ms_store(struct device
*dev
,
7188 struct device_attribute
*attr
,
7189 const char *buf
, size_t count
)
7191 struct pmu
*pmu
= dev_get_drvdata(dev
);
7192 int timer
, cpu
, ret
;
7194 ret
= kstrtoint(buf
, 0, &timer
);
7201 /* same value, noting to do */
7202 if (timer
== pmu
->hrtimer_interval_ms
)
7205 mutex_lock(&mux_interval_mutex
);
7206 pmu
->hrtimer_interval_ms
= timer
;
7208 /* update all cpuctx for this PMU */
7210 for_each_online_cpu(cpu
) {
7211 struct perf_cpu_context
*cpuctx
;
7212 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7213 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7215 cpu_function_call(cpu
,
7216 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7219 mutex_unlock(&mux_interval_mutex
);
7223 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7225 static struct attribute
*pmu_dev_attrs
[] = {
7226 &dev_attr_type
.attr
,
7227 &dev_attr_perf_event_mux_interval_ms
.attr
,
7230 ATTRIBUTE_GROUPS(pmu_dev
);
7232 static int pmu_bus_running
;
7233 static struct bus_type pmu_bus
= {
7234 .name
= "event_source",
7235 .dev_groups
= pmu_dev_groups
,
7238 static void pmu_dev_release(struct device
*dev
)
7243 static int pmu_dev_alloc(struct pmu
*pmu
)
7247 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7251 pmu
->dev
->groups
= pmu
->attr_groups
;
7252 device_initialize(pmu
->dev
);
7253 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7257 dev_set_drvdata(pmu
->dev
, pmu
);
7258 pmu
->dev
->bus
= &pmu_bus
;
7259 pmu
->dev
->release
= pmu_dev_release
;
7260 ret
= device_add(pmu
->dev
);
7268 put_device(pmu
->dev
);
7272 static struct lock_class_key cpuctx_mutex
;
7273 static struct lock_class_key cpuctx_lock
;
7275 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7279 mutex_lock(&pmus_lock
);
7281 pmu
->pmu_disable_count
= alloc_percpu(int);
7282 if (!pmu
->pmu_disable_count
)
7291 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7299 if (pmu_bus_running
) {
7300 ret
= pmu_dev_alloc(pmu
);
7306 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7307 if (pmu
->pmu_cpu_context
)
7308 goto got_cpu_context
;
7311 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7312 if (!pmu
->pmu_cpu_context
)
7315 for_each_possible_cpu(cpu
) {
7316 struct perf_cpu_context
*cpuctx
;
7318 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7319 __perf_event_init_context(&cpuctx
->ctx
);
7320 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7321 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7322 cpuctx
->ctx
.pmu
= pmu
;
7324 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7326 cpuctx
->unique_pmu
= pmu
;
7330 if (!pmu
->start_txn
) {
7331 if (pmu
->pmu_enable
) {
7333 * If we have pmu_enable/pmu_disable calls, install
7334 * transaction stubs that use that to try and batch
7335 * hardware accesses.
7337 pmu
->start_txn
= perf_pmu_start_txn
;
7338 pmu
->commit_txn
= perf_pmu_commit_txn
;
7339 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7341 pmu
->start_txn
= perf_pmu_nop_void
;
7342 pmu
->commit_txn
= perf_pmu_nop_int
;
7343 pmu
->cancel_txn
= perf_pmu_nop_void
;
7347 if (!pmu
->pmu_enable
) {
7348 pmu
->pmu_enable
= perf_pmu_nop_void
;
7349 pmu
->pmu_disable
= perf_pmu_nop_void
;
7352 if (!pmu
->event_idx
)
7353 pmu
->event_idx
= perf_event_idx_default
;
7355 list_add_rcu(&pmu
->entry
, &pmus
);
7356 atomic_set(&pmu
->exclusive_cnt
, 0);
7359 mutex_unlock(&pmus_lock
);
7364 device_del(pmu
->dev
);
7365 put_device(pmu
->dev
);
7368 if (pmu
->type
>= PERF_TYPE_MAX
)
7369 idr_remove(&pmu_idr
, pmu
->type
);
7372 free_percpu(pmu
->pmu_disable_count
);
7375 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7377 void perf_pmu_unregister(struct pmu
*pmu
)
7379 mutex_lock(&pmus_lock
);
7380 list_del_rcu(&pmu
->entry
);
7381 mutex_unlock(&pmus_lock
);
7384 * We dereference the pmu list under both SRCU and regular RCU, so
7385 * synchronize against both of those.
7387 synchronize_srcu(&pmus_srcu
);
7390 free_percpu(pmu
->pmu_disable_count
);
7391 if (pmu
->type
>= PERF_TYPE_MAX
)
7392 idr_remove(&pmu_idr
, pmu
->type
);
7393 device_del(pmu
->dev
);
7394 put_device(pmu
->dev
);
7395 free_pmu_context(pmu
);
7397 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7399 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7401 struct perf_event_context
*ctx
= NULL
;
7404 if (!try_module_get(pmu
->module
))
7407 if (event
->group_leader
!= event
) {
7409 * This ctx->mutex can nest when we're called through
7410 * inheritance. See the perf_event_ctx_lock_nested() comment.
7412 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7413 SINGLE_DEPTH_NESTING
);
7418 ret
= pmu
->event_init(event
);
7421 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7424 module_put(pmu
->module
);
7429 struct pmu
*perf_init_event(struct perf_event
*event
)
7431 struct pmu
*pmu
= NULL
;
7435 idx
= srcu_read_lock(&pmus_srcu
);
7438 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7441 ret
= perf_try_init_event(pmu
, event
);
7447 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7448 ret
= perf_try_init_event(pmu
, event
);
7452 if (ret
!= -ENOENT
) {
7457 pmu
= ERR_PTR(-ENOENT
);
7459 srcu_read_unlock(&pmus_srcu
, idx
);
7464 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7469 if (is_cgroup_event(event
))
7470 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7473 static void account_event(struct perf_event
*event
)
7478 if (event
->attach_state
& PERF_ATTACH_TASK
)
7479 static_key_slow_inc(&perf_sched_events
.key
);
7480 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7481 atomic_inc(&nr_mmap_events
);
7482 if (event
->attr
.comm
)
7483 atomic_inc(&nr_comm_events
);
7484 if (event
->attr
.task
)
7485 atomic_inc(&nr_task_events
);
7486 if (event
->attr
.freq
) {
7487 if (atomic_inc_return(&nr_freq_events
) == 1)
7488 tick_nohz_full_kick_all();
7490 if (has_branch_stack(event
))
7491 static_key_slow_inc(&perf_sched_events
.key
);
7492 if (is_cgroup_event(event
))
7493 static_key_slow_inc(&perf_sched_events
.key
);
7495 account_event_cpu(event
, event
->cpu
);
7499 * Allocate and initialize a event structure
7501 static struct perf_event
*
7502 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7503 struct task_struct
*task
,
7504 struct perf_event
*group_leader
,
7505 struct perf_event
*parent_event
,
7506 perf_overflow_handler_t overflow_handler
,
7507 void *context
, int cgroup_fd
)
7510 struct perf_event
*event
;
7511 struct hw_perf_event
*hwc
;
7514 if ((unsigned)cpu
>= nr_cpu_ids
) {
7515 if (!task
|| cpu
!= -1)
7516 return ERR_PTR(-EINVAL
);
7519 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7521 return ERR_PTR(-ENOMEM
);
7524 * Single events are their own group leaders, with an
7525 * empty sibling list:
7528 group_leader
= event
;
7530 mutex_init(&event
->child_mutex
);
7531 INIT_LIST_HEAD(&event
->child_list
);
7533 INIT_LIST_HEAD(&event
->group_entry
);
7534 INIT_LIST_HEAD(&event
->event_entry
);
7535 INIT_LIST_HEAD(&event
->sibling_list
);
7536 INIT_LIST_HEAD(&event
->rb_entry
);
7537 INIT_LIST_HEAD(&event
->active_entry
);
7538 INIT_HLIST_NODE(&event
->hlist_entry
);
7541 init_waitqueue_head(&event
->waitq
);
7542 init_irq_work(&event
->pending
, perf_pending_event
);
7544 mutex_init(&event
->mmap_mutex
);
7546 atomic_long_set(&event
->refcount
, 1);
7548 event
->attr
= *attr
;
7549 event
->group_leader
= group_leader
;
7553 event
->parent
= parent_event
;
7555 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7556 event
->id
= atomic64_inc_return(&perf_event_id
);
7558 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7561 event
->attach_state
= PERF_ATTACH_TASK
;
7563 * XXX pmu::event_init needs to know what task to account to
7564 * and we cannot use the ctx information because we need the
7565 * pmu before we get a ctx.
7567 event
->hw
.target
= task
;
7570 event
->clock
= &local_clock
;
7572 event
->clock
= parent_event
->clock
;
7574 if (!overflow_handler
&& parent_event
) {
7575 overflow_handler
= parent_event
->overflow_handler
;
7576 context
= parent_event
->overflow_handler_context
;
7579 event
->overflow_handler
= overflow_handler
;
7580 event
->overflow_handler_context
= context
;
7582 perf_event__state_init(event
);
7587 hwc
->sample_period
= attr
->sample_period
;
7588 if (attr
->freq
&& attr
->sample_freq
)
7589 hwc
->sample_period
= 1;
7590 hwc
->last_period
= hwc
->sample_period
;
7592 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7595 * we currently do not support PERF_FORMAT_GROUP on inherited events
7597 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7600 if (!has_branch_stack(event
))
7601 event
->attr
.branch_sample_type
= 0;
7603 if (cgroup_fd
!= -1) {
7604 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7609 pmu
= perf_init_event(event
);
7612 else if (IS_ERR(pmu
)) {
7617 err
= exclusive_event_init(event
);
7621 if (!event
->parent
) {
7622 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7623 err
= get_callchain_buffers();
7632 exclusive_event_destroy(event
);
7636 event
->destroy(event
);
7637 module_put(pmu
->module
);
7639 if (is_cgroup_event(event
))
7640 perf_detach_cgroup(event
);
7642 put_pid_ns(event
->ns
);
7645 return ERR_PTR(err
);
7648 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7649 struct perf_event_attr
*attr
)
7654 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7658 * zero the full structure, so that a short copy will be nice.
7660 memset(attr
, 0, sizeof(*attr
));
7662 ret
= get_user(size
, &uattr
->size
);
7666 if (size
> PAGE_SIZE
) /* silly large */
7669 if (!size
) /* abi compat */
7670 size
= PERF_ATTR_SIZE_VER0
;
7672 if (size
< PERF_ATTR_SIZE_VER0
)
7676 * If we're handed a bigger struct than we know of,
7677 * ensure all the unknown bits are 0 - i.e. new
7678 * user-space does not rely on any kernel feature
7679 * extensions we dont know about yet.
7681 if (size
> sizeof(*attr
)) {
7682 unsigned char __user
*addr
;
7683 unsigned char __user
*end
;
7686 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7687 end
= (void __user
*)uattr
+ size
;
7689 for (; addr
< end
; addr
++) {
7690 ret
= get_user(val
, addr
);
7696 size
= sizeof(*attr
);
7699 ret
= copy_from_user(attr
, uattr
, size
);
7703 if (attr
->__reserved_1
)
7706 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
7709 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
7712 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7713 u64 mask
= attr
->branch_sample_type
;
7715 /* only using defined bits */
7716 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
7719 /* at least one branch bit must be set */
7720 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
7723 /* propagate priv level, when not set for branch */
7724 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
7726 /* exclude_kernel checked on syscall entry */
7727 if (!attr
->exclude_kernel
)
7728 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
7730 if (!attr
->exclude_user
)
7731 mask
|= PERF_SAMPLE_BRANCH_USER
;
7733 if (!attr
->exclude_hv
)
7734 mask
|= PERF_SAMPLE_BRANCH_HV
;
7736 * adjust user setting (for HW filter setup)
7738 attr
->branch_sample_type
= mask
;
7740 /* privileged levels capture (kernel, hv): check permissions */
7741 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
7742 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
7746 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
7747 ret
= perf_reg_validate(attr
->sample_regs_user
);
7752 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
7753 if (!arch_perf_have_user_stack_dump())
7757 * We have __u32 type for the size, but so far
7758 * we can only use __u16 as maximum due to the
7759 * __u16 sample size limit.
7761 if (attr
->sample_stack_user
>= USHRT_MAX
)
7763 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
7767 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
7768 ret
= perf_reg_validate(attr
->sample_regs_intr
);
7773 put_user(sizeof(*attr
), &uattr
->size
);
7779 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
7781 struct ring_buffer
*rb
= NULL
;
7787 /* don't allow circular references */
7788 if (event
== output_event
)
7792 * Don't allow cross-cpu buffers
7794 if (output_event
->cpu
!= event
->cpu
)
7798 * If its not a per-cpu rb, it must be the same task.
7800 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
7804 * Mixing clocks in the same buffer is trouble you don't need.
7806 if (output_event
->clock
!= event
->clock
)
7810 * If both events generate aux data, they must be on the same PMU
7812 if (has_aux(event
) && has_aux(output_event
) &&
7813 event
->pmu
!= output_event
->pmu
)
7817 mutex_lock(&event
->mmap_mutex
);
7818 /* Can't redirect output if we've got an active mmap() */
7819 if (atomic_read(&event
->mmap_count
))
7823 /* get the rb we want to redirect to */
7824 rb
= ring_buffer_get(output_event
);
7829 ring_buffer_attach(event
, rb
);
7833 mutex_unlock(&event
->mmap_mutex
);
7839 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
7845 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
7848 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
7850 bool nmi_safe
= false;
7853 case CLOCK_MONOTONIC
:
7854 event
->clock
= &ktime_get_mono_fast_ns
;
7858 case CLOCK_MONOTONIC_RAW
:
7859 event
->clock
= &ktime_get_raw_fast_ns
;
7863 case CLOCK_REALTIME
:
7864 event
->clock
= &ktime_get_real_ns
;
7867 case CLOCK_BOOTTIME
:
7868 event
->clock
= &ktime_get_boot_ns
;
7872 event
->clock
= &ktime_get_tai_ns
;
7879 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
7886 * sys_perf_event_open - open a performance event, associate it to a task/cpu
7888 * @attr_uptr: event_id type attributes for monitoring/sampling
7891 * @group_fd: group leader event fd
7893 SYSCALL_DEFINE5(perf_event_open
,
7894 struct perf_event_attr __user
*, attr_uptr
,
7895 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
7897 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
7898 struct perf_event
*event
, *sibling
;
7899 struct perf_event_attr attr
;
7900 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
7901 struct file
*event_file
= NULL
;
7902 struct fd group
= {NULL
, 0};
7903 struct task_struct
*task
= NULL
;
7908 int f_flags
= O_RDWR
;
7911 /* for future expandability... */
7912 if (flags
& ~PERF_FLAG_ALL
)
7915 err
= perf_copy_attr(attr_uptr
, &attr
);
7919 if (!attr
.exclude_kernel
) {
7920 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
7925 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
7928 if (attr
.sample_period
& (1ULL << 63))
7933 * In cgroup mode, the pid argument is used to pass the fd
7934 * opened to the cgroup directory in cgroupfs. The cpu argument
7935 * designates the cpu on which to monitor threads from that
7938 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
7941 if (flags
& PERF_FLAG_FD_CLOEXEC
)
7942 f_flags
|= O_CLOEXEC
;
7944 event_fd
= get_unused_fd_flags(f_flags
);
7948 if (group_fd
!= -1) {
7949 err
= perf_fget_light(group_fd
, &group
);
7952 group_leader
= group
.file
->private_data
;
7953 if (flags
& PERF_FLAG_FD_OUTPUT
)
7954 output_event
= group_leader
;
7955 if (flags
& PERF_FLAG_FD_NO_GROUP
)
7956 group_leader
= NULL
;
7959 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
7960 task
= find_lively_task_by_vpid(pid
);
7962 err
= PTR_ERR(task
);
7967 if (task
&& group_leader
&&
7968 group_leader
->attr
.inherit
!= attr
.inherit
) {
7975 if (flags
& PERF_FLAG_PID_CGROUP
)
7978 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
7979 NULL
, NULL
, cgroup_fd
);
7980 if (IS_ERR(event
)) {
7981 err
= PTR_ERR(event
);
7985 if (is_sampling_event(event
)) {
7986 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
7992 account_event(event
);
7995 * Special case software events and allow them to be part of
7996 * any hardware group.
8000 if (attr
.use_clockid
) {
8001 err
= perf_event_set_clock(event
, attr
.clockid
);
8007 (is_software_event(event
) != is_software_event(group_leader
))) {
8008 if (is_software_event(event
)) {
8010 * If event and group_leader are not both a software
8011 * event, and event is, then group leader is not.
8013 * Allow the addition of software events to !software
8014 * groups, this is safe because software events never
8017 pmu
= group_leader
->pmu
;
8018 } else if (is_software_event(group_leader
) &&
8019 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8021 * In case the group is a pure software group, and we
8022 * try to add a hardware event, move the whole group to
8023 * the hardware context.
8030 * Get the target context (task or percpu):
8032 ctx
= find_get_context(pmu
, task
, event
);
8038 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8044 put_task_struct(task
);
8049 * Look up the group leader (we will attach this event to it):
8055 * Do not allow a recursive hierarchy (this new sibling
8056 * becoming part of another group-sibling):
8058 if (group_leader
->group_leader
!= group_leader
)
8061 /* All events in a group should have the same clock */
8062 if (group_leader
->clock
!= event
->clock
)
8066 * Do not allow to attach to a group in a different
8067 * task or CPU context:
8071 * Make sure we're both on the same task, or both
8074 if (group_leader
->ctx
->task
!= ctx
->task
)
8078 * Make sure we're both events for the same CPU;
8079 * grouping events for different CPUs is broken; since
8080 * you can never concurrently schedule them anyhow.
8082 if (group_leader
->cpu
!= event
->cpu
)
8085 if (group_leader
->ctx
!= ctx
)
8090 * Only a group leader can be exclusive or pinned
8092 if (attr
.exclusive
|| attr
.pinned
)
8097 err
= perf_event_set_output(event
, output_event
);
8102 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8104 if (IS_ERR(event_file
)) {
8105 err
= PTR_ERR(event_file
);
8110 gctx
= group_leader
->ctx
;
8113 * See perf_event_ctx_lock() for comments on the details
8114 * of swizzling perf_event::ctx.
8116 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8118 perf_remove_from_context(group_leader
, false);
8120 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8122 perf_remove_from_context(sibling
, false);
8126 mutex_lock(&ctx
->mutex
);
8129 WARN_ON_ONCE(ctx
->parent_ctx
);
8133 * Wait for everybody to stop referencing the events through
8134 * the old lists, before installing it on new lists.
8139 * Install the group siblings before the group leader.
8141 * Because a group leader will try and install the entire group
8142 * (through the sibling list, which is still in-tact), we can
8143 * end up with siblings installed in the wrong context.
8145 * By installing siblings first we NO-OP because they're not
8146 * reachable through the group lists.
8148 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8150 perf_event__state_init(sibling
);
8151 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8156 * Removing from the context ends up with disabled
8157 * event. What we want here is event in the initial
8158 * startup state, ready to be add into new context.
8160 perf_event__state_init(group_leader
);
8161 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8165 if (!exclusive_event_installable(event
, ctx
)) {
8167 mutex_unlock(&ctx
->mutex
);
8172 perf_install_in_context(ctx
, event
, event
->cpu
);
8173 perf_unpin_context(ctx
);
8176 mutex_unlock(&gctx
->mutex
);
8179 mutex_unlock(&ctx
->mutex
);
8183 event
->owner
= current
;
8185 mutex_lock(¤t
->perf_event_mutex
);
8186 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8187 mutex_unlock(¤t
->perf_event_mutex
);
8190 * Precalculate sample_data sizes
8192 perf_event__header_size(event
);
8193 perf_event__id_header_size(event
);
8196 * Drop the reference on the group_event after placing the
8197 * new event on the sibling_list. This ensures destruction
8198 * of the group leader will find the pointer to itself in
8199 * perf_group_detach().
8202 fd_install(event_fd
, event_file
);
8206 perf_unpin_context(ctx
);
8214 put_task_struct(task
);
8218 put_unused_fd(event_fd
);
8223 * perf_event_create_kernel_counter
8225 * @attr: attributes of the counter to create
8226 * @cpu: cpu in which the counter is bound
8227 * @task: task to profile (NULL for percpu)
8230 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8231 struct task_struct
*task
,
8232 perf_overflow_handler_t overflow_handler
,
8235 struct perf_event_context
*ctx
;
8236 struct perf_event
*event
;
8240 * Get the target context (task or percpu):
8243 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8244 overflow_handler
, context
, -1);
8245 if (IS_ERR(event
)) {
8246 err
= PTR_ERR(event
);
8250 /* Mark owner so we could distinguish it from user events. */
8251 event
->owner
= EVENT_OWNER_KERNEL
;
8253 account_event(event
);
8255 ctx
= find_get_context(event
->pmu
, task
, event
);
8261 WARN_ON_ONCE(ctx
->parent_ctx
);
8262 mutex_lock(&ctx
->mutex
);
8263 if (!exclusive_event_installable(event
, ctx
)) {
8264 mutex_unlock(&ctx
->mutex
);
8265 perf_unpin_context(ctx
);
8271 perf_install_in_context(ctx
, event
, cpu
);
8272 perf_unpin_context(ctx
);
8273 mutex_unlock(&ctx
->mutex
);
8280 return ERR_PTR(err
);
8282 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8284 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8286 struct perf_event_context
*src_ctx
;
8287 struct perf_event_context
*dst_ctx
;
8288 struct perf_event
*event
, *tmp
;
8291 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8292 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8295 * See perf_event_ctx_lock() for comments on the details
8296 * of swizzling perf_event::ctx.
8298 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8299 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8301 perf_remove_from_context(event
, false);
8302 unaccount_event_cpu(event
, src_cpu
);
8304 list_add(&event
->migrate_entry
, &events
);
8308 * Wait for the events to quiesce before re-instating them.
8313 * Re-instate events in 2 passes.
8315 * Skip over group leaders and only install siblings on this first
8316 * pass, siblings will not get enabled without a leader, however a
8317 * leader will enable its siblings, even if those are still on the old
8320 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8321 if (event
->group_leader
== event
)
8324 list_del(&event
->migrate_entry
);
8325 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8326 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8327 account_event_cpu(event
, dst_cpu
);
8328 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8333 * Once all the siblings are setup properly, install the group leaders
8336 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8337 list_del(&event
->migrate_entry
);
8338 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8339 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8340 account_event_cpu(event
, dst_cpu
);
8341 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8344 mutex_unlock(&dst_ctx
->mutex
);
8345 mutex_unlock(&src_ctx
->mutex
);
8347 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8349 static void sync_child_event(struct perf_event
*child_event
,
8350 struct task_struct
*child
)
8352 struct perf_event
*parent_event
= child_event
->parent
;
8355 if (child_event
->attr
.inherit_stat
)
8356 perf_event_read_event(child_event
, child
);
8358 child_val
= perf_event_count(child_event
);
8361 * Add back the child's count to the parent's count:
8363 atomic64_add(child_val
, &parent_event
->child_count
);
8364 atomic64_add(child_event
->total_time_enabled
,
8365 &parent_event
->child_total_time_enabled
);
8366 atomic64_add(child_event
->total_time_running
,
8367 &parent_event
->child_total_time_running
);
8370 * Remove this event from the parent's list
8372 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8373 mutex_lock(&parent_event
->child_mutex
);
8374 list_del_init(&child_event
->child_list
);
8375 mutex_unlock(&parent_event
->child_mutex
);
8378 * Make sure user/parent get notified, that we just
8381 perf_event_wakeup(parent_event
);
8384 * Release the parent event, if this was the last
8387 put_event(parent_event
);
8391 __perf_event_exit_task(struct perf_event
*child_event
,
8392 struct perf_event_context
*child_ctx
,
8393 struct task_struct
*child
)
8396 * Do not destroy the 'original' grouping; because of the context
8397 * switch optimization the original events could've ended up in a
8398 * random child task.
8400 * If we were to destroy the original group, all group related
8401 * operations would cease to function properly after this random
8404 * Do destroy all inherited groups, we don't care about those
8405 * and being thorough is better.
8407 perf_remove_from_context(child_event
, !!child_event
->parent
);
8410 * It can happen that the parent exits first, and has events
8411 * that are still around due to the child reference. These
8412 * events need to be zapped.
8414 if (child_event
->parent
) {
8415 sync_child_event(child_event
, child
);
8416 free_event(child_event
);
8418 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8419 perf_event_wakeup(child_event
);
8423 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8425 struct perf_event
*child_event
, *next
;
8426 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8427 unsigned long flags
;
8429 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
8430 perf_event_task(child
, NULL
, 0);
8434 local_irq_save(flags
);
8436 * We can't reschedule here because interrupts are disabled,
8437 * and either child is current or it is a task that can't be
8438 * scheduled, so we are now safe from rescheduling changing
8441 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8444 * Take the context lock here so that if find_get_context is
8445 * reading child->perf_event_ctxp, we wait until it has
8446 * incremented the context's refcount before we do put_ctx below.
8448 raw_spin_lock(&child_ctx
->lock
);
8449 task_ctx_sched_out(child_ctx
);
8450 child
->perf_event_ctxp
[ctxn
] = NULL
;
8453 * If this context is a clone; unclone it so it can't get
8454 * swapped to another process while we're removing all
8455 * the events from it.
8457 clone_ctx
= unclone_ctx(child_ctx
);
8458 update_context_time(child_ctx
);
8459 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8465 * Report the task dead after unscheduling the events so that we
8466 * won't get any samples after PERF_RECORD_EXIT. We can however still
8467 * get a few PERF_RECORD_READ events.
8469 perf_event_task(child
, child_ctx
, 0);
8472 * We can recurse on the same lock type through:
8474 * __perf_event_exit_task()
8475 * sync_child_event()
8477 * mutex_lock(&ctx->mutex)
8479 * But since its the parent context it won't be the same instance.
8481 mutex_lock(&child_ctx
->mutex
);
8483 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8484 __perf_event_exit_task(child_event
, child_ctx
, child
);
8486 mutex_unlock(&child_ctx
->mutex
);
8492 * When a child task exits, feed back event values to parent events.
8494 void perf_event_exit_task(struct task_struct
*child
)
8496 struct perf_event
*event
, *tmp
;
8499 mutex_lock(&child
->perf_event_mutex
);
8500 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8502 list_del_init(&event
->owner_entry
);
8505 * Ensure the list deletion is visible before we clear
8506 * the owner, closes a race against perf_release() where
8507 * we need to serialize on the owner->perf_event_mutex.
8510 event
->owner
= NULL
;
8512 mutex_unlock(&child
->perf_event_mutex
);
8514 for_each_task_context_nr(ctxn
)
8515 perf_event_exit_task_context(child
, ctxn
);
8518 static void perf_free_event(struct perf_event
*event
,
8519 struct perf_event_context
*ctx
)
8521 struct perf_event
*parent
= event
->parent
;
8523 if (WARN_ON_ONCE(!parent
))
8526 mutex_lock(&parent
->child_mutex
);
8527 list_del_init(&event
->child_list
);
8528 mutex_unlock(&parent
->child_mutex
);
8532 raw_spin_lock_irq(&ctx
->lock
);
8533 perf_group_detach(event
);
8534 list_del_event(event
, ctx
);
8535 raw_spin_unlock_irq(&ctx
->lock
);
8540 * Free an unexposed, unused context as created by inheritance by
8541 * perf_event_init_task below, used by fork() in case of fail.
8543 * Not all locks are strictly required, but take them anyway to be nice and
8544 * help out with the lockdep assertions.
8546 void perf_event_free_task(struct task_struct
*task
)
8548 struct perf_event_context
*ctx
;
8549 struct perf_event
*event
, *tmp
;
8552 for_each_task_context_nr(ctxn
) {
8553 ctx
= task
->perf_event_ctxp
[ctxn
];
8557 mutex_lock(&ctx
->mutex
);
8559 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8561 perf_free_event(event
, ctx
);
8563 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8565 perf_free_event(event
, ctx
);
8567 if (!list_empty(&ctx
->pinned_groups
) ||
8568 !list_empty(&ctx
->flexible_groups
))
8571 mutex_unlock(&ctx
->mutex
);
8577 void perf_event_delayed_put(struct task_struct
*task
)
8581 for_each_task_context_nr(ctxn
)
8582 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8586 * inherit a event from parent task to child task:
8588 static struct perf_event
*
8589 inherit_event(struct perf_event
*parent_event
,
8590 struct task_struct
*parent
,
8591 struct perf_event_context
*parent_ctx
,
8592 struct task_struct
*child
,
8593 struct perf_event
*group_leader
,
8594 struct perf_event_context
*child_ctx
)
8596 enum perf_event_active_state parent_state
= parent_event
->state
;
8597 struct perf_event
*child_event
;
8598 unsigned long flags
;
8601 * Instead of creating recursive hierarchies of events,
8602 * we link inherited events back to the original parent,
8603 * which has a filp for sure, which we use as the reference
8606 if (parent_event
->parent
)
8607 parent_event
= parent_event
->parent
;
8609 child_event
= perf_event_alloc(&parent_event
->attr
,
8612 group_leader
, parent_event
,
8614 if (IS_ERR(child_event
))
8617 if (is_orphaned_event(parent_event
) ||
8618 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8619 free_event(child_event
);
8626 * Make the child state follow the state of the parent event,
8627 * not its attr.disabled bit. We hold the parent's mutex,
8628 * so we won't race with perf_event_{en, dis}able_family.
8630 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8631 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8633 child_event
->state
= PERF_EVENT_STATE_OFF
;
8635 if (parent_event
->attr
.freq
) {
8636 u64 sample_period
= parent_event
->hw
.sample_period
;
8637 struct hw_perf_event
*hwc
= &child_event
->hw
;
8639 hwc
->sample_period
= sample_period
;
8640 hwc
->last_period
= sample_period
;
8642 local64_set(&hwc
->period_left
, sample_period
);
8645 child_event
->ctx
= child_ctx
;
8646 child_event
->overflow_handler
= parent_event
->overflow_handler
;
8647 child_event
->overflow_handler_context
8648 = parent_event
->overflow_handler_context
;
8651 * Precalculate sample_data sizes
8653 perf_event__header_size(child_event
);
8654 perf_event__id_header_size(child_event
);
8657 * Link it up in the child's context:
8659 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
8660 add_event_to_ctx(child_event
, child_ctx
);
8661 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8664 * Link this into the parent event's child list
8666 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8667 mutex_lock(&parent_event
->child_mutex
);
8668 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
8669 mutex_unlock(&parent_event
->child_mutex
);
8674 static int inherit_group(struct perf_event
*parent_event
,
8675 struct task_struct
*parent
,
8676 struct perf_event_context
*parent_ctx
,
8677 struct task_struct
*child
,
8678 struct perf_event_context
*child_ctx
)
8680 struct perf_event
*leader
;
8681 struct perf_event
*sub
;
8682 struct perf_event
*child_ctr
;
8684 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
8685 child
, NULL
, child_ctx
);
8687 return PTR_ERR(leader
);
8688 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
8689 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
8690 child
, leader
, child_ctx
);
8691 if (IS_ERR(child_ctr
))
8692 return PTR_ERR(child_ctr
);
8698 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
8699 struct perf_event_context
*parent_ctx
,
8700 struct task_struct
*child
, int ctxn
,
8704 struct perf_event_context
*child_ctx
;
8706 if (!event
->attr
.inherit
) {
8711 child_ctx
= child
->perf_event_ctxp
[ctxn
];
8714 * This is executed from the parent task context, so
8715 * inherit events that have been marked for cloning.
8716 * First allocate and initialize a context for the
8720 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
8724 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
8727 ret
= inherit_group(event
, parent
, parent_ctx
,
8737 * Initialize the perf_event context in task_struct
8739 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
8741 struct perf_event_context
*child_ctx
, *parent_ctx
;
8742 struct perf_event_context
*cloned_ctx
;
8743 struct perf_event
*event
;
8744 struct task_struct
*parent
= current
;
8745 int inherited_all
= 1;
8746 unsigned long flags
;
8749 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
8753 * If the parent's context is a clone, pin it so it won't get
8756 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
8761 * No need to check if parent_ctx != NULL here; since we saw
8762 * it non-NULL earlier, the only reason for it to become NULL
8763 * is if we exit, and since we're currently in the middle of
8764 * a fork we can't be exiting at the same time.
8768 * Lock the parent list. No need to lock the child - not PID
8769 * hashed yet and not running, so nobody can access it.
8771 mutex_lock(&parent_ctx
->mutex
);
8774 * We dont have to disable NMIs - we are only looking at
8775 * the list, not manipulating it:
8777 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
8778 ret
= inherit_task_group(event
, parent
, parent_ctx
,
8779 child
, ctxn
, &inherited_all
);
8785 * We can't hold ctx->lock when iterating the ->flexible_group list due
8786 * to allocations, but we need to prevent rotation because
8787 * rotate_ctx() will change the list from interrupt context.
8789 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
8790 parent_ctx
->rotate_disable
= 1;
8791 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
8793 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
8794 ret
= inherit_task_group(event
, parent
, parent_ctx
,
8795 child
, ctxn
, &inherited_all
);
8800 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
8801 parent_ctx
->rotate_disable
= 0;
8803 child_ctx
= child
->perf_event_ctxp
[ctxn
];
8805 if (child_ctx
&& inherited_all
) {
8807 * Mark the child context as a clone of the parent
8808 * context, or of whatever the parent is a clone of.
8810 * Note that if the parent is a clone, the holding of
8811 * parent_ctx->lock avoids it from being uncloned.
8813 cloned_ctx
= parent_ctx
->parent_ctx
;
8815 child_ctx
->parent_ctx
= cloned_ctx
;
8816 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
8818 child_ctx
->parent_ctx
= parent_ctx
;
8819 child_ctx
->parent_gen
= parent_ctx
->generation
;
8821 get_ctx(child_ctx
->parent_ctx
);
8824 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
8825 mutex_unlock(&parent_ctx
->mutex
);
8827 perf_unpin_context(parent_ctx
);
8828 put_ctx(parent_ctx
);
8834 * Initialize the perf_event context in task_struct
8836 int perf_event_init_task(struct task_struct
*child
)
8840 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
8841 mutex_init(&child
->perf_event_mutex
);
8842 INIT_LIST_HEAD(&child
->perf_event_list
);
8844 for_each_task_context_nr(ctxn
) {
8845 ret
= perf_event_init_context(child
, ctxn
);
8847 perf_event_free_task(child
);
8855 static void __init
perf_event_init_all_cpus(void)
8857 struct swevent_htable
*swhash
;
8860 for_each_possible_cpu(cpu
) {
8861 swhash
= &per_cpu(swevent_htable
, cpu
);
8862 mutex_init(&swhash
->hlist_mutex
);
8863 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
8867 static void perf_event_init_cpu(int cpu
)
8869 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8871 mutex_lock(&swhash
->hlist_mutex
);
8872 swhash
->online
= true;
8873 if (swhash
->hlist_refcount
> 0) {
8874 struct swevent_hlist
*hlist
;
8876 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
8878 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
8880 mutex_unlock(&swhash
->hlist_mutex
);
8883 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
8884 static void __perf_event_exit_context(void *__info
)
8886 struct remove_event re
= { .detach_group
= true };
8887 struct perf_event_context
*ctx
= __info
;
8890 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
8891 __perf_remove_from_context(&re
);
8895 static void perf_event_exit_cpu_context(int cpu
)
8897 struct perf_event_context
*ctx
;
8901 idx
= srcu_read_lock(&pmus_srcu
);
8902 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
8903 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
8905 mutex_lock(&ctx
->mutex
);
8906 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
8907 mutex_unlock(&ctx
->mutex
);
8909 srcu_read_unlock(&pmus_srcu
, idx
);
8912 static void perf_event_exit_cpu(int cpu
)
8914 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8916 perf_event_exit_cpu_context(cpu
);
8918 mutex_lock(&swhash
->hlist_mutex
);
8919 swhash
->online
= false;
8920 swevent_hlist_release(swhash
);
8921 mutex_unlock(&swhash
->hlist_mutex
);
8924 static inline void perf_event_exit_cpu(int cpu
) { }
8928 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
8932 for_each_online_cpu(cpu
)
8933 perf_event_exit_cpu(cpu
);
8939 * Run the perf reboot notifier at the very last possible moment so that
8940 * the generic watchdog code runs as long as possible.
8942 static struct notifier_block perf_reboot_notifier
= {
8943 .notifier_call
= perf_reboot
,
8944 .priority
= INT_MIN
,
8948 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
8950 unsigned int cpu
= (long)hcpu
;
8952 switch (action
& ~CPU_TASKS_FROZEN
) {
8954 case CPU_UP_PREPARE
:
8955 case CPU_DOWN_FAILED
:
8956 perf_event_init_cpu(cpu
);
8959 case CPU_UP_CANCELED
:
8960 case CPU_DOWN_PREPARE
:
8961 perf_event_exit_cpu(cpu
);
8970 void __init
perf_event_init(void)
8976 perf_event_init_all_cpus();
8977 init_srcu_struct(&pmus_srcu
);
8978 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
8979 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
8980 perf_pmu_register(&perf_task_clock
, NULL
, -1);
8982 perf_cpu_notifier(perf_cpu_notify
);
8983 register_reboot_notifier(&perf_reboot_notifier
);
8985 ret
= init_hw_breakpoint();
8986 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
8988 /* do not patch jump label more than once per second */
8989 jump_label_rate_limit(&perf_sched_events
, HZ
);
8992 * Build time assertion that we keep the data_head at the intended
8993 * location. IOW, validation we got the __reserved[] size right.
8995 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
8999 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9002 struct perf_pmu_events_attr
*pmu_attr
=
9003 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9005 if (pmu_attr
->event_str
)
9006 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9011 static int __init
perf_event_sysfs_init(void)
9016 mutex_lock(&pmus_lock
);
9018 ret
= bus_register(&pmu_bus
);
9022 list_for_each_entry(pmu
, &pmus
, entry
) {
9023 if (!pmu
->name
|| pmu
->type
< 0)
9026 ret
= pmu_dev_alloc(pmu
);
9027 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9029 pmu_bus_running
= 1;
9033 mutex_unlock(&pmus_lock
);
9037 device_initcall(perf_event_sysfs_init
);
9039 #ifdef CONFIG_CGROUP_PERF
9040 static struct cgroup_subsys_state
*
9041 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9043 struct perf_cgroup
*jc
;
9045 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9047 return ERR_PTR(-ENOMEM
);
9049 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9052 return ERR_PTR(-ENOMEM
);
9058 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9060 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9062 free_percpu(jc
->info
);
9066 static int __perf_cgroup_move(void *info
)
9068 struct task_struct
*task
= info
;
9069 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9073 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
9074 struct cgroup_taskset
*tset
)
9076 struct task_struct
*task
;
9078 cgroup_taskset_for_each(task
, tset
)
9079 task_function_call(task
, __perf_cgroup_move
, task
);
9082 static void perf_cgroup_exit(struct cgroup_subsys_state
*css
,
9083 struct cgroup_subsys_state
*old_css
,
9084 struct task_struct
*task
)
9087 * cgroup_exit() is called in the copy_process() failure path.
9088 * Ignore this case since the task hasn't ran yet, this avoids
9089 * trying to poke a half freed task state from generic code.
9091 if (!(task
->flags
& PF_EXITING
))
9094 task_function_call(task
, __perf_cgroup_move
, task
);
9097 struct cgroup_subsys perf_event_cgrp_subsys
= {
9098 .css_alloc
= perf_cgroup_css_alloc
,
9099 .css_free
= perf_cgroup_css_free
,
9100 .exit
= perf_cgroup_exit
,
9101 .attach
= perf_cgroup_attach
,
9103 #endif /* CONFIG_CGROUP_PERF */