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
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
50 #include <asm/irq_regs.h>
52 static struct workqueue_struct
*perf_wq
;
54 typedef int (*remote_function_f
)(void *);
56 struct remote_function_call
{
57 struct task_struct
*p
;
58 remote_function_f func
;
63 static void remote_function(void *data
)
65 struct remote_function_call
*tfc
= data
;
66 struct task_struct
*p
= tfc
->p
;
70 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
74 tfc
->ret
= tfc
->func(tfc
->info
);
78 * task_function_call - call a function on the cpu on which a task runs
79 * @p: the task to evaluate
80 * @func: the function to be called
81 * @info: the function call argument
83 * Calls the function @func when the task is currently running. This might
84 * be on the current CPU, which just calls the function directly
86 * returns: @func return value, or
87 * -ESRCH - when the process isn't running
88 * -EAGAIN - when the process moved away
91 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
93 struct remote_function_call data
= {
97 .ret
= -ESRCH
, /* No such (running) process */
101 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
107 * cpu_function_call - call a function on the cpu
108 * @func: the function to be called
109 * @info: the function call argument
111 * Calls the function @func on the remote cpu.
113 * returns: @func return value or -ENXIO when the cpu is offline
115 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
117 struct remote_function_call data
= {
121 .ret
= -ENXIO
, /* No such CPU */
124 smp_call_function_single(cpu
, remote_function
, &data
, 1);
129 #define EVENT_OWNER_KERNEL ((void *) -1)
131 static bool is_kernel_event(struct perf_event
*event
)
133 return event
->owner
== EVENT_OWNER_KERNEL
;
136 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
137 PERF_FLAG_FD_OUTPUT |\
138 PERF_FLAG_PID_CGROUP |\
139 PERF_FLAG_FD_CLOEXEC)
142 * branch priv levels that need permission checks
144 #define PERF_SAMPLE_BRANCH_PERM_PLM \
145 (PERF_SAMPLE_BRANCH_KERNEL |\
146 PERF_SAMPLE_BRANCH_HV)
149 EVENT_FLEXIBLE
= 0x1,
151 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
155 * perf_sched_events : >0 events exist
156 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
158 struct static_key_deferred perf_sched_events __read_mostly
;
159 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
160 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
162 static atomic_t nr_mmap_events __read_mostly
;
163 static atomic_t nr_comm_events __read_mostly
;
164 static atomic_t nr_task_events __read_mostly
;
165 static atomic_t nr_freq_events __read_mostly
;
166 static atomic_t nr_switch_events __read_mostly
;
168 static LIST_HEAD(pmus
);
169 static DEFINE_MUTEX(pmus_lock
);
170 static struct srcu_struct pmus_srcu
;
173 * perf event paranoia level:
174 * -1 - not paranoid at all
175 * 0 - disallow raw tracepoint access for unpriv
176 * 1 - disallow cpu events for unpriv
177 * 2 - disallow kernel profiling for unpriv
179 int sysctl_perf_event_paranoid __read_mostly
= 1;
181 /* Minimum for 512 kiB + 1 user control page */
182 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
185 * max perf event sample rate
187 #define DEFAULT_MAX_SAMPLE_RATE 100000
188 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
189 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
191 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
193 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
194 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
196 static int perf_sample_allowed_ns __read_mostly
=
197 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
199 static void update_perf_cpu_limits(void)
201 u64 tmp
= perf_sample_period_ns
;
203 tmp
*= sysctl_perf_cpu_time_max_percent
;
205 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
208 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
210 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
211 void __user
*buffer
, size_t *lenp
,
214 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
219 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
220 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
221 update_perf_cpu_limits();
226 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
228 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
229 void __user
*buffer
, size_t *lenp
,
232 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
237 update_perf_cpu_limits();
243 * perf samples are done in some very critical code paths (NMIs).
244 * If they take too much CPU time, the system can lock up and not
245 * get any real work done. This will drop the sample rate when
246 * we detect that events are taking too long.
248 #define NR_ACCUMULATED_SAMPLES 128
249 static DEFINE_PER_CPU(u64
, running_sample_length
);
251 static void perf_duration_warn(struct irq_work
*w
)
253 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
254 u64 avg_local_sample_len
;
255 u64 local_samples_len
;
257 local_samples_len
= __this_cpu_read(running_sample_length
);
258 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
260 printk_ratelimited(KERN_WARNING
261 "perf interrupt took too long (%lld > %lld), lowering "
262 "kernel.perf_event_max_sample_rate to %d\n",
263 avg_local_sample_len
, allowed_ns
>> 1,
264 sysctl_perf_event_sample_rate
);
267 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
269 void perf_sample_event_took(u64 sample_len_ns
)
271 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
272 u64 avg_local_sample_len
;
273 u64 local_samples_len
;
278 /* decay the counter by 1 average sample */
279 local_samples_len
= __this_cpu_read(running_sample_length
);
280 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
281 local_samples_len
+= sample_len_ns
;
282 __this_cpu_write(running_sample_length
, local_samples_len
);
285 * note: this will be biased artifically low until we have
286 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
287 * from having to maintain a count.
289 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
291 if (avg_local_sample_len
<= allowed_ns
)
294 if (max_samples_per_tick
<= 1)
297 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
298 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
299 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
301 update_perf_cpu_limits();
303 if (!irq_work_queue(&perf_duration_work
)) {
304 early_printk("perf interrupt took too long (%lld > %lld), lowering "
305 "kernel.perf_event_max_sample_rate to %d\n",
306 avg_local_sample_len
, allowed_ns
>> 1,
307 sysctl_perf_event_sample_rate
);
311 static atomic64_t perf_event_id
;
313 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
314 enum event_type_t event_type
);
316 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
317 enum event_type_t event_type
,
318 struct task_struct
*task
);
320 static void update_context_time(struct perf_event_context
*ctx
);
321 static u64
perf_event_time(struct perf_event
*event
);
323 void __weak
perf_event_print_debug(void) { }
325 extern __weak
const char *perf_pmu_name(void)
330 static inline u64
perf_clock(void)
332 return local_clock();
335 static inline u64
perf_event_clock(struct perf_event
*event
)
337 return event
->clock();
340 static inline struct perf_cpu_context
*
341 __get_cpu_context(struct perf_event_context
*ctx
)
343 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
346 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
347 struct perf_event_context
*ctx
)
349 raw_spin_lock(&cpuctx
->ctx
.lock
);
351 raw_spin_lock(&ctx
->lock
);
354 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
355 struct perf_event_context
*ctx
)
358 raw_spin_unlock(&ctx
->lock
);
359 raw_spin_unlock(&cpuctx
->ctx
.lock
);
362 #ifdef CONFIG_CGROUP_PERF
365 perf_cgroup_match(struct perf_event
*event
)
367 struct perf_event_context
*ctx
= event
->ctx
;
368 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
370 /* @event doesn't care about cgroup */
374 /* wants specific cgroup scope but @cpuctx isn't associated with any */
379 * Cgroup scoping is recursive. An event enabled for a cgroup is
380 * also enabled for all its descendant cgroups. If @cpuctx's
381 * cgroup is a descendant of @event's (the test covers identity
382 * case), it's a match.
384 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
385 event
->cgrp
->css
.cgroup
);
388 static inline void perf_detach_cgroup(struct perf_event
*event
)
390 css_put(&event
->cgrp
->css
);
394 static inline int is_cgroup_event(struct perf_event
*event
)
396 return event
->cgrp
!= NULL
;
399 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
401 struct perf_cgroup_info
*t
;
403 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
407 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
409 struct perf_cgroup_info
*info
;
414 info
= this_cpu_ptr(cgrp
->info
);
416 info
->time
+= now
- info
->timestamp
;
417 info
->timestamp
= now
;
420 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
422 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
424 __update_cgrp_time(cgrp_out
);
427 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
429 struct perf_cgroup
*cgrp
;
432 * ensure we access cgroup data only when needed and
433 * when we know the cgroup is pinned (css_get)
435 if (!is_cgroup_event(event
))
438 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
440 * Do not update time when cgroup is not active
442 if (cgrp
== event
->cgrp
)
443 __update_cgrp_time(event
->cgrp
);
447 perf_cgroup_set_timestamp(struct task_struct
*task
,
448 struct perf_event_context
*ctx
)
450 struct perf_cgroup
*cgrp
;
451 struct perf_cgroup_info
*info
;
454 * ctx->lock held by caller
455 * ensure we do not access cgroup data
456 * unless we have the cgroup pinned (css_get)
458 if (!task
|| !ctx
->nr_cgroups
)
461 cgrp
= perf_cgroup_from_task(task
, ctx
);
462 info
= this_cpu_ptr(cgrp
->info
);
463 info
->timestamp
= ctx
->timestamp
;
466 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
467 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
470 * reschedule events based on the cgroup constraint of task.
472 * mode SWOUT : schedule out everything
473 * mode SWIN : schedule in based on cgroup for next
475 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
477 struct perf_cpu_context
*cpuctx
;
482 * disable interrupts to avoid geting nr_cgroup
483 * changes via __perf_event_disable(). Also
486 local_irq_save(flags
);
489 * we reschedule only in the presence of cgroup
490 * constrained events.
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
524 * we pass the cpuctx->ctx to perf_cgroup_from_task()
525 * because cgorup events are only per-cpu
527 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
528 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
530 perf_pmu_enable(cpuctx
->ctx
.pmu
);
531 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
;
546 * we come here when we know perf_cgroup_events > 0
547 * we do not need to pass the ctx here because we know
548 * we are holding the rcu lock
550 cgrp1
= perf_cgroup_from_task(task
, NULL
);
553 * next is NULL when called from perf_event_enable_on_exec()
554 * that will systematically cause a cgroup_switch()
557 cgrp2
= perf_cgroup_from_task(next
, NULL
);
560 * only schedule out current cgroup events if we know
561 * that we are switching to a different cgroup. Otherwise,
562 * do no touch the cgroup events.
565 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
570 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
571 struct task_struct
*task
)
573 struct perf_cgroup
*cgrp1
;
574 struct perf_cgroup
*cgrp2
= NULL
;
578 * we come here when we know perf_cgroup_events > 0
579 * we do not need to pass the ctx here because we know
580 * we are holding the rcu lock
582 cgrp1
= perf_cgroup_from_task(task
, NULL
);
584 /* prev can never be NULL */
585 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
588 * only need to schedule in cgroup events if we are changing
589 * cgroup during ctxsw. Cgroup events were not scheduled
590 * out of ctxsw out if that was not the case.
593 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
598 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
599 struct perf_event_attr
*attr
,
600 struct perf_event
*group_leader
)
602 struct perf_cgroup
*cgrp
;
603 struct cgroup_subsys_state
*css
;
604 struct fd f
= fdget(fd
);
610 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
611 &perf_event_cgrp_subsys
);
617 cgrp
= container_of(css
, struct perf_cgroup
, css
);
621 * all events in a group must monitor
622 * the same cgroup because a task belongs
623 * to only one perf cgroup at a time
625 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
626 perf_detach_cgroup(event
);
635 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
637 struct perf_cgroup_info
*t
;
638 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
639 event
->shadow_ctx_time
= now
- t
->timestamp
;
643 perf_cgroup_defer_enabled(struct perf_event
*event
)
646 * when the current task's perf cgroup does not match
647 * the event's, we need to remember to call the
648 * perf_mark_enable() function the first time a task with
649 * a matching perf cgroup is scheduled in.
651 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
652 event
->cgrp_defer_enabled
= 1;
656 perf_cgroup_mark_enabled(struct perf_event
*event
,
657 struct perf_event_context
*ctx
)
659 struct perf_event
*sub
;
660 u64 tstamp
= perf_event_time(event
);
662 if (!event
->cgrp_defer_enabled
)
665 event
->cgrp_defer_enabled
= 0;
667 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
668 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
669 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
670 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
671 sub
->cgrp_defer_enabled
= 0;
675 #else /* !CONFIG_CGROUP_PERF */
678 perf_cgroup_match(struct perf_event
*event
)
683 static inline void perf_detach_cgroup(struct perf_event
*event
)
686 static inline int is_cgroup_event(struct perf_event
*event
)
691 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
696 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
700 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
704 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
705 struct task_struct
*next
)
709 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
710 struct task_struct
*task
)
714 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
715 struct perf_event_attr
*attr
,
716 struct perf_event
*group_leader
)
722 perf_cgroup_set_timestamp(struct task_struct
*task
,
723 struct perf_event_context
*ctx
)
728 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
733 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
737 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
743 perf_cgroup_defer_enabled(struct perf_event
*event
)
748 perf_cgroup_mark_enabled(struct perf_event
*event
,
749 struct perf_event_context
*ctx
)
755 * set default to be dependent on timer tick just
758 #define PERF_CPU_HRTIMER (1000 / HZ)
760 * function must be called with interrupts disbled
762 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
764 struct perf_cpu_context
*cpuctx
;
767 WARN_ON(!irqs_disabled());
769 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
770 rotations
= perf_rotate_context(cpuctx
);
772 raw_spin_lock(&cpuctx
->hrtimer_lock
);
774 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
776 cpuctx
->hrtimer_active
= 0;
777 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
779 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
782 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
784 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
785 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
788 /* no multiplexing needed for SW PMU */
789 if (pmu
->task_ctx_nr
== perf_sw_context
)
793 * check default is sane, if not set then force to
794 * default interval (1/tick)
796 interval
= pmu
->hrtimer_interval_ms
;
798 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
800 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
802 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
803 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
804 timer
->function
= perf_mux_hrtimer_handler
;
807 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
809 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
810 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
814 if (pmu
->task_ctx_nr
== perf_sw_context
)
817 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
818 if (!cpuctx
->hrtimer_active
) {
819 cpuctx
->hrtimer_active
= 1;
820 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
821 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
823 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
828 void perf_pmu_disable(struct pmu
*pmu
)
830 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
832 pmu
->pmu_disable(pmu
);
835 void perf_pmu_enable(struct pmu
*pmu
)
837 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
839 pmu
->pmu_enable(pmu
);
842 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
845 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
846 * perf_event_task_tick() are fully serialized because they're strictly cpu
847 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
848 * disabled, while perf_event_task_tick is called from IRQ context.
850 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
852 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
854 WARN_ON(!irqs_disabled());
856 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
858 list_add(&ctx
->active_ctx_list
, head
);
861 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
863 WARN_ON(!irqs_disabled());
865 WARN_ON(list_empty(&ctx
->active_ctx_list
));
867 list_del_init(&ctx
->active_ctx_list
);
870 static void get_ctx(struct perf_event_context
*ctx
)
872 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
875 static void free_ctx(struct rcu_head
*head
)
877 struct perf_event_context
*ctx
;
879 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
880 kfree(ctx
->task_ctx_data
);
884 static void put_ctx(struct perf_event_context
*ctx
)
886 if (atomic_dec_and_test(&ctx
->refcount
)) {
888 put_ctx(ctx
->parent_ctx
);
890 put_task_struct(ctx
->task
);
891 call_rcu(&ctx
->rcu_head
, free_ctx
);
896 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
897 * perf_pmu_migrate_context() we need some magic.
899 * Those places that change perf_event::ctx will hold both
900 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
902 * Lock ordering is by mutex address. There are two other sites where
903 * perf_event_context::mutex nests and those are:
905 * - perf_event_exit_task_context() [ child , 0 ]
906 * __perf_event_exit_task()
908 * put_event() [ parent, 1 ]
910 * - perf_event_init_context() [ parent, 0 ]
911 * inherit_task_group()
916 * perf_try_init_event() [ child , 1 ]
918 * While it appears there is an obvious deadlock here -- the parent and child
919 * nesting levels are inverted between the two. This is in fact safe because
920 * life-time rules separate them. That is an exiting task cannot fork, and a
921 * spawning task cannot (yet) exit.
923 * But remember that that these are parent<->child context relations, and
924 * migration does not affect children, therefore these two orderings should not
927 * The change in perf_event::ctx does not affect children (as claimed above)
928 * because the sys_perf_event_open() case will install a new event and break
929 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
930 * concerned with cpuctx and that doesn't have children.
932 * The places that change perf_event::ctx will issue:
934 * perf_remove_from_context();
936 * perf_install_in_context();
938 * to affect the change. The remove_from_context() + synchronize_rcu() should
939 * quiesce the event, after which we can install it in the new location. This
940 * means that only external vectors (perf_fops, prctl) can perturb the event
941 * while in transit. Therefore all such accessors should also acquire
942 * perf_event_context::mutex to serialize against this.
944 * However; because event->ctx can change while we're waiting to acquire
945 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
949 * task_struct::perf_event_mutex
950 * perf_event_context::mutex
951 * perf_event_context::lock
952 * perf_event::child_mutex;
953 * perf_event::mmap_mutex
956 static struct perf_event_context
*
957 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
959 struct perf_event_context
*ctx
;
963 ctx
= ACCESS_ONCE(event
->ctx
);
964 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
970 mutex_lock_nested(&ctx
->mutex
, nesting
);
971 if (event
->ctx
!= ctx
) {
972 mutex_unlock(&ctx
->mutex
);
980 static inline struct perf_event_context
*
981 perf_event_ctx_lock(struct perf_event
*event
)
983 return perf_event_ctx_lock_nested(event
, 0);
986 static void perf_event_ctx_unlock(struct perf_event
*event
,
987 struct perf_event_context
*ctx
)
989 mutex_unlock(&ctx
->mutex
);
994 * This must be done under the ctx->lock, such as to serialize against
995 * context_equiv(), therefore we cannot call put_ctx() since that might end up
996 * calling scheduler related locks and ctx->lock nests inside those.
998 static __must_check
struct perf_event_context
*
999 unclone_ctx(struct perf_event_context
*ctx
)
1001 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1003 lockdep_assert_held(&ctx
->lock
);
1006 ctx
->parent_ctx
= NULL
;
1012 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1015 * only top level events have the pid namespace they were created in
1018 event
= event
->parent
;
1020 return task_tgid_nr_ns(p
, event
->ns
);
1023 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1026 * only top level events have the pid namespace they were created in
1029 event
= event
->parent
;
1031 return task_pid_nr_ns(p
, event
->ns
);
1035 * If we inherit events we want to return the parent event id
1038 static u64
primary_event_id(struct perf_event
*event
)
1043 id
= event
->parent
->id
;
1049 * Get the perf_event_context for a task and lock it.
1050 * This has to cope with with the fact that until it is locked,
1051 * the context could get moved to another task.
1053 static struct perf_event_context
*
1054 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1056 struct perf_event_context
*ctx
;
1060 * One of the few rules of preemptible RCU is that one cannot do
1061 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1062 * part of the read side critical section was irqs-enabled -- see
1063 * rcu_read_unlock_special().
1065 * Since ctx->lock nests under rq->lock we must ensure the entire read
1066 * side critical section has interrupts disabled.
1068 local_irq_save(*flags
);
1070 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1073 * If this context is a clone of another, it might
1074 * get swapped for another underneath us by
1075 * perf_event_task_sched_out, though the
1076 * rcu_read_lock() protects us from any context
1077 * getting freed. Lock the context and check if it
1078 * got swapped before we could get the lock, and retry
1079 * if so. If we locked the right context, then it
1080 * can't get swapped on us any more.
1082 raw_spin_lock(&ctx
->lock
);
1083 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1084 raw_spin_unlock(&ctx
->lock
);
1086 local_irq_restore(*flags
);
1090 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1091 raw_spin_unlock(&ctx
->lock
);
1097 local_irq_restore(*flags
);
1102 * Get the context for a task and increment its pin_count so it
1103 * can't get swapped to another task. This also increments its
1104 * reference count so that the context can't get freed.
1106 static struct perf_event_context
*
1107 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1109 struct perf_event_context
*ctx
;
1110 unsigned long flags
;
1112 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1115 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1120 static void perf_unpin_context(struct perf_event_context
*ctx
)
1122 unsigned long flags
;
1124 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1126 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1130 * Update the record of the current time in a context.
1132 static void update_context_time(struct perf_event_context
*ctx
)
1134 u64 now
= perf_clock();
1136 ctx
->time
+= now
- ctx
->timestamp
;
1137 ctx
->timestamp
= now
;
1140 static u64
perf_event_time(struct perf_event
*event
)
1142 struct perf_event_context
*ctx
= event
->ctx
;
1144 if (is_cgroup_event(event
))
1145 return perf_cgroup_event_time(event
);
1147 return ctx
? ctx
->time
: 0;
1151 * Update the total_time_enabled and total_time_running fields for a event.
1152 * The caller of this function needs to hold the ctx->lock.
1154 static void update_event_times(struct perf_event
*event
)
1156 struct perf_event_context
*ctx
= event
->ctx
;
1159 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1160 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1163 * in cgroup mode, time_enabled represents
1164 * the time the event was enabled AND active
1165 * tasks were in the monitored cgroup. This is
1166 * independent of the activity of the context as
1167 * there may be a mix of cgroup and non-cgroup events.
1169 * That is why we treat cgroup events differently
1172 if (is_cgroup_event(event
))
1173 run_end
= perf_cgroup_event_time(event
);
1174 else if (ctx
->is_active
)
1175 run_end
= ctx
->time
;
1177 run_end
= event
->tstamp_stopped
;
1179 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1181 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1182 run_end
= event
->tstamp_stopped
;
1184 run_end
= perf_event_time(event
);
1186 event
->total_time_running
= run_end
- event
->tstamp_running
;
1191 * Update total_time_enabled and total_time_running for all events in a group.
1193 static void update_group_times(struct perf_event
*leader
)
1195 struct perf_event
*event
;
1197 update_event_times(leader
);
1198 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1199 update_event_times(event
);
1202 static struct list_head
*
1203 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1205 if (event
->attr
.pinned
)
1206 return &ctx
->pinned_groups
;
1208 return &ctx
->flexible_groups
;
1212 * Add a event from the lists for its context.
1213 * Must be called with ctx->mutex and ctx->lock held.
1216 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1218 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1219 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1222 * If we're a stand alone event or group leader, we go to the context
1223 * list, group events are kept attached to the group so that
1224 * perf_group_detach can, at all times, locate all siblings.
1226 if (event
->group_leader
== event
) {
1227 struct list_head
*list
;
1229 if (is_software_event(event
))
1230 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1232 list
= ctx_group_list(event
, ctx
);
1233 list_add_tail(&event
->group_entry
, list
);
1236 if (is_cgroup_event(event
))
1239 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1241 if (event
->attr
.inherit_stat
)
1248 * Initialize event state based on the perf_event_attr::disabled.
1250 static inline void perf_event__state_init(struct perf_event
*event
)
1252 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1253 PERF_EVENT_STATE_INACTIVE
;
1256 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1258 int entry
= sizeof(u64
); /* value */
1262 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1263 size
+= sizeof(u64
);
1265 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1266 size
+= sizeof(u64
);
1268 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1269 entry
+= sizeof(u64
);
1271 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1273 size
+= sizeof(u64
);
1277 event
->read_size
= size
;
1280 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1282 struct perf_sample_data
*data
;
1285 if (sample_type
& PERF_SAMPLE_IP
)
1286 size
+= sizeof(data
->ip
);
1288 if (sample_type
& PERF_SAMPLE_ADDR
)
1289 size
+= sizeof(data
->addr
);
1291 if (sample_type
& PERF_SAMPLE_PERIOD
)
1292 size
+= sizeof(data
->period
);
1294 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1295 size
+= sizeof(data
->weight
);
1297 if (sample_type
& PERF_SAMPLE_READ
)
1298 size
+= event
->read_size
;
1300 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1301 size
+= sizeof(data
->data_src
.val
);
1303 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1304 size
+= sizeof(data
->txn
);
1306 event
->header_size
= size
;
1310 * Called at perf_event creation and when events are attached/detached from a
1313 static void perf_event__header_size(struct perf_event
*event
)
1315 __perf_event_read_size(event
,
1316 event
->group_leader
->nr_siblings
);
1317 __perf_event_header_size(event
, event
->attr
.sample_type
);
1320 static void perf_event__id_header_size(struct perf_event
*event
)
1322 struct perf_sample_data
*data
;
1323 u64 sample_type
= event
->attr
.sample_type
;
1326 if (sample_type
& PERF_SAMPLE_TID
)
1327 size
+= sizeof(data
->tid_entry
);
1329 if (sample_type
& PERF_SAMPLE_TIME
)
1330 size
+= sizeof(data
->time
);
1332 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1333 size
+= sizeof(data
->id
);
1335 if (sample_type
& PERF_SAMPLE_ID
)
1336 size
+= sizeof(data
->id
);
1338 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1339 size
+= sizeof(data
->stream_id
);
1341 if (sample_type
& PERF_SAMPLE_CPU
)
1342 size
+= sizeof(data
->cpu_entry
);
1344 event
->id_header_size
= size
;
1347 static bool perf_event_validate_size(struct perf_event
*event
)
1350 * The values computed here will be over-written when we actually
1353 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1354 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1355 perf_event__id_header_size(event
);
1358 * Sum the lot; should not exceed the 64k limit we have on records.
1359 * Conservative limit to allow for callchains and other variable fields.
1361 if (event
->read_size
+ event
->header_size
+
1362 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1368 static void perf_group_attach(struct perf_event
*event
)
1370 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1373 * We can have double attach due to group movement in perf_event_open.
1375 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1378 event
->attach_state
|= PERF_ATTACH_GROUP
;
1380 if (group_leader
== event
)
1383 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1385 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1386 !is_software_event(event
))
1387 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1389 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1390 group_leader
->nr_siblings
++;
1392 perf_event__header_size(group_leader
);
1394 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1395 perf_event__header_size(pos
);
1399 * Remove a event from the lists for its context.
1400 * Must be called with ctx->mutex and ctx->lock held.
1403 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1405 struct perf_cpu_context
*cpuctx
;
1407 WARN_ON_ONCE(event
->ctx
!= ctx
);
1408 lockdep_assert_held(&ctx
->lock
);
1411 * We can have double detach due to exit/hot-unplug + close.
1413 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1416 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1418 if (is_cgroup_event(event
)) {
1420 cpuctx
= __get_cpu_context(ctx
);
1422 * if there are no more cgroup events
1423 * then cler cgrp to avoid stale pointer
1424 * in update_cgrp_time_from_cpuctx()
1426 if (!ctx
->nr_cgroups
)
1427 cpuctx
->cgrp
= NULL
;
1431 if (event
->attr
.inherit_stat
)
1434 list_del_rcu(&event
->event_entry
);
1436 if (event
->group_leader
== event
)
1437 list_del_init(&event
->group_entry
);
1439 update_group_times(event
);
1442 * If event was in error state, then keep it
1443 * that way, otherwise bogus counts will be
1444 * returned on read(). The only way to get out
1445 * of error state is by explicit re-enabling
1448 if (event
->state
> PERF_EVENT_STATE_OFF
)
1449 event
->state
= PERF_EVENT_STATE_OFF
;
1454 static void perf_group_detach(struct perf_event
*event
)
1456 struct perf_event
*sibling
, *tmp
;
1457 struct list_head
*list
= NULL
;
1460 * We can have double detach due to exit/hot-unplug + close.
1462 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1465 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1468 * If this is a sibling, remove it from its group.
1470 if (event
->group_leader
!= event
) {
1471 list_del_init(&event
->group_entry
);
1472 event
->group_leader
->nr_siblings
--;
1476 if (!list_empty(&event
->group_entry
))
1477 list
= &event
->group_entry
;
1480 * If this was a group event with sibling events then
1481 * upgrade the siblings to singleton events by adding them
1482 * to whatever list we are on.
1484 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1486 list_move_tail(&sibling
->group_entry
, list
);
1487 sibling
->group_leader
= sibling
;
1489 /* Inherit group flags from the previous leader */
1490 sibling
->group_flags
= event
->group_flags
;
1492 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1496 perf_event__header_size(event
->group_leader
);
1498 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1499 perf_event__header_size(tmp
);
1503 * User event without the task.
1505 static bool is_orphaned_event(struct perf_event
*event
)
1507 return event
&& !is_kernel_event(event
) && !event
->owner
;
1511 * Event has a parent but parent's task finished and it's
1512 * alive only because of children holding refference.
1514 static bool is_orphaned_child(struct perf_event
*event
)
1516 return is_orphaned_event(event
->parent
);
1519 static void orphans_remove_work(struct work_struct
*work
);
1521 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1523 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1526 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1528 ctx
->orphans_remove_sched
= true;
1532 static int __init
perf_workqueue_init(void)
1534 perf_wq
= create_singlethread_workqueue("perf");
1535 WARN(!perf_wq
, "failed to create perf workqueue\n");
1536 return perf_wq
? 0 : -1;
1539 core_initcall(perf_workqueue_init
);
1541 static inline int pmu_filter_match(struct perf_event
*event
)
1543 struct pmu
*pmu
= event
->pmu
;
1544 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1548 event_filter_match(struct perf_event
*event
)
1550 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1551 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1555 event_sched_out(struct perf_event
*event
,
1556 struct perf_cpu_context
*cpuctx
,
1557 struct perf_event_context
*ctx
)
1559 u64 tstamp
= perf_event_time(event
);
1562 WARN_ON_ONCE(event
->ctx
!= ctx
);
1563 lockdep_assert_held(&ctx
->lock
);
1566 * An event which could not be activated because of
1567 * filter mismatch still needs to have its timings
1568 * maintained, otherwise bogus information is return
1569 * via read() for time_enabled, time_running:
1571 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1572 && !event_filter_match(event
)) {
1573 delta
= tstamp
- event
->tstamp_stopped
;
1574 event
->tstamp_running
+= delta
;
1575 event
->tstamp_stopped
= tstamp
;
1578 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1581 perf_pmu_disable(event
->pmu
);
1583 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1584 if (event
->pending_disable
) {
1585 event
->pending_disable
= 0;
1586 event
->state
= PERF_EVENT_STATE_OFF
;
1588 event
->tstamp_stopped
= tstamp
;
1589 event
->pmu
->del(event
, 0);
1592 if (!is_software_event(event
))
1593 cpuctx
->active_oncpu
--;
1594 if (!--ctx
->nr_active
)
1595 perf_event_ctx_deactivate(ctx
);
1596 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1598 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1599 cpuctx
->exclusive
= 0;
1601 if (is_orphaned_child(event
))
1602 schedule_orphans_remove(ctx
);
1604 perf_pmu_enable(event
->pmu
);
1608 group_sched_out(struct perf_event
*group_event
,
1609 struct perf_cpu_context
*cpuctx
,
1610 struct perf_event_context
*ctx
)
1612 struct perf_event
*event
;
1613 int state
= group_event
->state
;
1615 event_sched_out(group_event
, cpuctx
, ctx
);
1618 * Schedule out siblings (if any):
1620 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1621 event_sched_out(event
, cpuctx
, ctx
);
1623 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1624 cpuctx
->exclusive
= 0;
1627 struct remove_event
{
1628 struct perf_event
*event
;
1633 * Cross CPU call to remove a performance event
1635 * We disable the event on the hardware level first. After that we
1636 * remove it from the context list.
1638 static int __perf_remove_from_context(void *info
)
1640 struct remove_event
*re
= info
;
1641 struct perf_event
*event
= re
->event
;
1642 struct perf_event_context
*ctx
= event
->ctx
;
1643 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1645 raw_spin_lock(&ctx
->lock
);
1646 event_sched_out(event
, cpuctx
, ctx
);
1647 if (re
->detach_group
)
1648 perf_group_detach(event
);
1649 list_del_event(event
, ctx
);
1650 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1652 cpuctx
->task_ctx
= NULL
;
1654 raw_spin_unlock(&ctx
->lock
);
1661 * Remove the event from a task's (or a CPU's) list of events.
1663 * CPU events are removed with a smp call. For task events we only
1664 * call when the task is on a CPU.
1666 * If event->ctx is a cloned context, callers must make sure that
1667 * every task struct that event->ctx->task could possibly point to
1668 * remains valid. This is OK when called from perf_release since
1669 * that only calls us on the top-level context, which can't be a clone.
1670 * When called from perf_event_exit_task, it's OK because the
1671 * context has been detached from its task.
1673 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1675 struct perf_event_context
*ctx
= event
->ctx
;
1676 struct task_struct
*task
= ctx
->task
;
1677 struct remove_event re
= {
1679 .detach_group
= detach_group
,
1682 lockdep_assert_held(&ctx
->mutex
);
1686 * Per cpu events are removed via an smp call. The removal can
1687 * fail if the CPU is currently offline, but in that case we
1688 * already called __perf_remove_from_context from
1689 * perf_event_exit_cpu.
1691 cpu_function_call(event
->cpu
, __perf_remove_from_context
, &re
);
1696 if (!task_function_call(task
, __perf_remove_from_context
, &re
))
1699 raw_spin_lock_irq(&ctx
->lock
);
1701 * If we failed to find a running task, but find the context active now
1702 * that we've acquired the ctx->lock, retry.
1704 if (ctx
->is_active
) {
1705 raw_spin_unlock_irq(&ctx
->lock
);
1707 * Reload the task pointer, it might have been changed by
1708 * a concurrent perf_event_context_sched_out().
1715 * Since the task isn't running, its safe to remove the event, us
1716 * holding the ctx->lock ensures the task won't get scheduled in.
1719 perf_group_detach(event
);
1720 list_del_event(event
, ctx
);
1721 raw_spin_unlock_irq(&ctx
->lock
);
1725 * Cross CPU call to disable a performance event
1727 int __perf_event_disable(void *info
)
1729 struct perf_event
*event
= info
;
1730 struct perf_event_context
*ctx
= event
->ctx
;
1731 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1734 * If this is a per-task event, need to check whether this
1735 * event's task is the current task on this cpu.
1737 * Can trigger due to concurrent perf_event_context_sched_out()
1738 * flipping contexts around.
1740 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1743 raw_spin_lock(&ctx
->lock
);
1746 * If the event is on, turn it off.
1747 * If it is in error state, leave it in error state.
1749 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1750 update_context_time(ctx
);
1751 update_cgrp_time_from_event(event
);
1752 update_group_times(event
);
1753 if (event
== event
->group_leader
)
1754 group_sched_out(event
, cpuctx
, ctx
);
1756 event_sched_out(event
, cpuctx
, ctx
);
1757 event
->state
= PERF_EVENT_STATE_OFF
;
1760 raw_spin_unlock(&ctx
->lock
);
1768 * If event->ctx is a cloned context, callers must make sure that
1769 * every task struct that event->ctx->task could possibly point to
1770 * remains valid. This condition is satisifed when called through
1771 * perf_event_for_each_child or perf_event_for_each because they
1772 * hold the top-level event's child_mutex, so any descendant that
1773 * goes to exit will block in sync_child_event.
1774 * When called from perf_pending_event it's OK because event->ctx
1775 * is the current context on this CPU and preemption is disabled,
1776 * hence we can't get into perf_event_task_sched_out for this context.
1778 static void _perf_event_disable(struct perf_event
*event
)
1780 struct perf_event_context
*ctx
= event
->ctx
;
1781 struct task_struct
*task
= ctx
->task
;
1785 * Disable the event on the cpu that it's on
1787 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1792 if (!task_function_call(task
, __perf_event_disable
, event
))
1795 raw_spin_lock_irq(&ctx
->lock
);
1797 * If the event is still active, we need to retry the cross-call.
1799 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1800 raw_spin_unlock_irq(&ctx
->lock
);
1802 * Reload the task pointer, it might have been changed by
1803 * a concurrent perf_event_context_sched_out().
1810 * Since we have the lock this context can't be scheduled
1811 * in, so we can change the state safely.
1813 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1814 update_group_times(event
);
1815 event
->state
= PERF_EVENT_STATE_OFF
;
1817 raw_spin_unlock_irq(&ctx
->lock
);
1821 * Strictly speaking kernel users cannot create groups and therefore this
1822 * interface does not need the perf_event_ctx_lock() magic.
1824 void perf_event_disable(struct perf_event
*event
)
1826 struct perf_event_context
*ctx
;
1828 ctx
= perf_event_ctx_lock(event
);
1829 _perf_event_disable(event
);
1830 perf_event_ctx_unlock(event
, ctx
);
1832 EXPORT_SYMBOL_GPL(perf_event_disable
);
1834 static void perf_set_shadow_time(struct perf_event
*event
,
1835 struct perf_event_context
*ctx
,
1839 * use the correct time source for the time snapshot
1841 * We could get by without this by leveraging the
1842 * fact that to get to this function, the caller
1843 * has most likely already called update_context_time()
1844 * and update_cgrp_time_xx() and thus both timestamp
1845 * are identical (or very close). Given that tstamp is,
1846 * already adjusted for cgroup, we could say that:
1847 * tstamp - ctx->timestamp
1849 * tstamp - cgrp->timestamp.
1851 * Then, in perf_output_read(), the calculation would
1852 * work with no changes because:
1853 * - event is guaranteed scheduled in
1854 * - no scheduled out in between
1855 * - thus the timestamp would be the same
1857 * But this is a bit hairy.
1859 * So instead, we have an explicit cgroup call to remain
1860 * within the time time source all along. We believe it
1861 * is cleaner and simpler to understand.
1863 if (is_cgroup_event(event
))
1864 perf_cgroup_set_shadow_time(event
, tstamp
);
1866 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1869 #define MAX_INTERRUPTS (~0ULL)
1871 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1872 static void perf_log_itrace_start(struct perf_event
*event
);
1875 event_sched_in(struct perf_event
*event
,
1876 struct perf_cpu_context
*cpuctx
,
1877 struct perf_event_context
*ctx
)
1879 u64 tstamp
= perf_event_time(event
);
1882 lockdep_assert_held(&ctx
->lock
);
1884 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1887 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1888 event
->oncpu
= smp_processor_id();
1891 * Unthrottle events, since we scheduled we might have missed several
1892 * ticks already, also for a heavily scheduling task there is little
1893 * guarantee it'll get a tick in a timely manner.
1895 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1896 perf_log_throttle(event
, 1);
1897 event
->hw
.interrupts
= 0;
1901 * The new state must be visible before we turn it on in the hardware:
1905 perf_pmu_disable(event
->pmu
);
1907 perf_set_shadow_time(event
, ctx
, tstamp
);
1909 perf_log_itrace_start(event
);
1911 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1912 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1918 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1920 if (!is_software_event(event
))
1921 cpuctx
->active_oncpu
++;
1922 if (!ctx
->nr_active
++)
1923 perf_event_ctx_activate(ctx
);
1924 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1927 if (event
->attr
.exclusive
)
1928 cpuctx
->exclusive
= 1;
1930 if (is_orphaned_child(event
))
1931 schedule_orphans_remove(ctx
);
1934 perf_pmu_enable(event
->pmu
);
1940 group_sched_in(struct perf_event
*group_event
,
1941 struct perf_cpu_context
*cpuctx
,
1942 struct perf_event_context
*ctx
)
1944 struct perf_event
*event
, *partial_group
= NULL
;
1945 struct pmu
*pmu
= ctx
->pmu
;
1946 u64 now
= ctx
->time
;
1947 bool simulate
= false;
1949 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1952 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1954 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1955 pmu
->cancel_txn(pmu
);
1956 perf_mux_hrtimer_restart(cpuctx
);
1961 * Schedule in siblings as one group (if any):
1963 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1964 if (event_sched_in(event
, cpuctx
, ctx
)) {
1965 partial_group
= event
;
1970 if (!pmu
->commit_txn(pmu
))
1975 * Groups can be scheduled in as one unit only, so undo any
1976 * partial group before returning:
1977 * The events up to the failed event are scheduled out normally,
1978 * tstamp_stopped will be updated.
1980 * The failed events and the remaining siblings need to have
1981 * their timings updated as if they had gone thru event_sched_in()
1982 * and event_sched_out(). This is required to get consistent timings
1983 * across the group. This also takes care of the case where the group
1984 * could never be scheduled by ensuring tstamp_stopped is set to mark
1985 * the time the event was actually stopped, such that time delta
1986 * calculation in update_event_times() is correct.
1988 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1989 if (event
== partial_group
)
1993 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1994 event
->tstamp_stopped
= now
;
1996 event_sched_out(event
, cpuctx
, ctx
);
1999 event_sched_out(group_event
, cpuctx
, ctx
);
2001 pmu
->cancel_txn(pmu
);
2003 perf_mux_hrtimer_restart(cpuctx
);
2009 * Work out whether we can put this event group on the CPU now.
2011 static int group_can_go_on(struct perf_event
*event
,
2012 struct perf_cpu_context
*cpuctx
,
2016 * Groups consisting entirely of software events can always go on.
2018 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2021 * If an exclusive group is already on, no other hardware
2024 if (cpuctx
->exclusive
)
2027 * If this group is exclusive and there are already
2028 * events on the CPU, it can't go on.
2030 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2033 * Otherwise, try to add it if all previous groups were able
2039 static void add_event_to_ctx(struct perf_event
*event
,
2040 struct perf_event_context
*ctx
)
2042 u64 tstamp
= perf_event_time(event
);
2044 list_add_event(event
, ctx
);
2045 perf_group_attach(event
);
2046 event
->tstamp_enabled
= tstamp
;
2047 event
->tstamp_running
= tstamp
;
2048 event
->tstamp_stopped
= tstamp
;
2051 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
2053 ctx_sched_in(struct perf_event_context
*ctx
,
2054 struct perf_cpu_context
*cpuctx
,
2055 enum event_type_t event_type
,
2056 struct task_struct
*task
);
2058 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2059 struct perf_event_context
*ctx
,
2060 struct task_struct
*task
)
2062 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2064 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2065 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2067 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2071 * Cross CPU call to install and enable a performance event
2073 * Must be called with ctx->mutex held
2075 static int __perf_install_in_context(void *info
)
2077 struct perf_event
*event
= info
;
2078 struct perf_event_context
*ctx
= event
->ctx
;
2079 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2080 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2081 struct task_struct
*task
= current
;
2083 perf_ctx_lock(cpuctx
, task_ctx
);
2084 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2087 * If there was an active task_ctx schedule it out.
2090 task_ctx_sched_out(task_ctx
);
2093 * If the context we're installing events in is not the
2094 * active task_ctx, flip them.
2096 if (ctx
->task
&& task_ctx
!= ctx
) {
2098 raw_spin_unlock(&task_ctx
->lock
);
2099 raw_spin_lock(&ctx
->lock
);
2104 cpuctx
->task_ctx
= task_ctx
;
2105 task
= task_ctx
->task
;
2108 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2110 update_context_time(ctx
);
2112 * update cgrp time only if current cgrp
2113 * matches event->cgrp. Must be done before
2114 * calling add_event_to_ctx()
2116 update_cgrp_time_from_event(event
);
2118 add_event_to_ctx(event
, ctx
);
2121 * Schedule everything back in
2123 perf_event_sched_in(cpuctx
, task_ctx
, task
);
2125 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2126 perf_ctx_unlock(cpuctx
, task_ctx
);
2132 * Attach a performance event to a context
2134 * First we add the event to the list with the hardware enable bit
2135 * in event->hw_config cleared.
2137 * If the event is attached to a task which is on a CPU we use a smp
2138 * call to enable it in the task context. The task might have been
2139 * scheduled away, but we check this in the smp call again.
2142 perf_install_in_context(struct perf_event_context
*ctx
,
2143 struct perf_event
*event
,
2146 struct task_struct
*task
= ctx
->task
;
2148 lockdep_assert_held(&ctx
->mutex
);
2151 if (event
->cpu
!= -1)
2156 * Per cpu events are installed via an smp call and
2157 * the install is always successful.
2159 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2164 if (!task_function_call(task
, __perf_install_in_context
, event
))
2167 raw_spin_lock_irq(&ctx
->lock
);
2169 * If we failed to find a running task, but find the context active now
2170 * that we've acquired the ctx->lock, retry.
2172 if (ctx
->is_active
) {
2173 raw_spin_unlock_irq(&ctx
->lock
);
2175 * Reload the task pointer, it might have been changed by
2176 * a concurrent perf_event_context_sched_out().
2183 * Since the task isn't running, its safe to add the event, us holding
2184 * the ctx->lock ensures the task won't get scheduled in.
2186 add_event_to_ctx(event
, ctx
);
2187 raw_spin_unlock_irq(&ctx
->lock
);
2191 * Put a event into inactive state and update time fields.
2192 * Enabling the leader of a group effectively enables all
2193 * the group members that aren't explicitly disabled, so we
2194 * have to update their ->tstamp_enabled also.
2195 * Note: this works for group members as well as group leaders
2196 * since the non-leader members' sibling_lists will be empty.
2198 static void __perf_event_mark_enabled(struct perf_event
*event
)
2200 struct perf_event
*sub
;
2201 u64 tstamp
= perf_event_time(event
);
2203 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2204 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2205 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2206 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2207 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2212 * Cross CPU call to enable a performance event
2214 static int __perf_event_enable(void *info
)
2216 struct perf_event
*event
= info
;
2217 struct perf_event_context
*ctx
= event
->ctx
;
2218 struct perf_event
*leader
= event
->group_leader
;
2219 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2223 * There's a time window between 'ctx->is_active' check
2224 * in perf_event_enable function and this place having:
2226 * - ctx->lock unlocked
2228 * where the task could be killed and 'ctx' deactivated
2229 * by perf_event_exit_task.
2231 if (!ctx
->is_active
)
2234 raw_spin_lock(&ctx
->lock
);
2235 update_context_time(ctx
);
2237 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2241 * set current task's cgroup time reference point
2243 perf_cgroup_set_timestamp(current
, ctx
);
2245 __perf_event_mark_enabled(event
);
2247 if (!event_filter_match(event
)) {
2248 if (is_cgroup_event(event
))
2249 perf_cgroup_defer_enabled(event
);
2254 * If the event is in a group and isn't the group leader,
2255 * then don't put it on unless the group is on.
2257 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2260 if (!group_can_go_on(event
, cpuctx
, 1)) {
2263 if (event
== leader
)
2264 err
= group_sched_in(event
, cpuctx
, ctx
);
2266 err
= event_sched_in(event
, cpuctx
, ctx
);
2271 * If this event can't go on and it's part of a
2272 * group, then the whole group has to come off.
2274 if (leader
!= event
) {
2275 group_sched_out(leader
, cpuctx
, ctx
);
2276 perf_mux_hrtimer_restart(cpuctx
);
2278 if (leader
->attr
.pinned
) {
2279 update_group_times(leader
);
2280 leader
->state
= PERF_EVENT_STATE_ERROR
;
2285 raw_spin_unlock(&ctx
->lock
);
2293 * If event->ctx is a cloned context, callers must make sure that
2294 * every task struct that event->ctx->task could possibly point to
2295 * remains valid. This condition is satisfied when called through
2296 * perf_event_for_each_child or perf_event_for_each as described
2297 * for perf_event_disable.
2299 static void _perf_event_enable(struct perf_event
*event
)
2301 struct perf_event_context
*ctx
= event
->ctx
;
2302 struct task_struct
*task
= ctx
->task
;
2306 * Enable the event on the cpu that it's on
2308 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2312 raw_spin_lock_irq(&ctx
->lock
);
2313 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2317 * If the event is in error state, clear that first.
2318 * That way, if we see the event in error state below, we
2319 * know that it has gone back into error state, as distinct
2320 * from the task having been scheduled away before the
2321 * cross-call arrived.
2323 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2324 event
->state
= PERF_EVENT_STATE_OFF
;
2327 if (!ctx
->is_active
) {
2328 __perf_event_mark_enabled(event
);
2332 raw_spin_unlock_irq(&ctx
->lock
);
2334 if (!task_function_call(task
, __perf_event_enable
, event
))
2337 raw_spin_lock_irq(&ctx
->lock
);
2340 * If the context is active and the event is still off,
2341 * we need to retry the cross-call.
2343 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2345 * task could have been flipped by a concurrent
2346 * perf_event_context_sched_out()
2353 raw_spin_unlock_irq(&ctx
->lock
);
2357 * See perf_event_disable();
2359 void perf_event_enable(struct perf_event
*event
)
2361 struct perf_event_context
*ctx
;
2363 ctx
= perf_event_ctx_lock(event
);
2364 _perf_event_enable(event
);
2365 perf_event_ctx_unlock(event
, ctx
);
2367 EXPORT_SYMBOL_GPL(perf_event_enable
);
2369 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2372 * not supported on inherited events
2374 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2377 atomic_add(refresh
, &event
->event_limit
);
2378 _perf_event_enable(event
);
2384 * See perf_event_disable()
2386 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2388 struct perf_event_context
*ctx
;
2391 ctx
= perf_event_ctx_lock(event
);
2392 ret
= _perf_event_refresh(event
, refresh
);
2393 perf_event_ctx_unlock(event
, ctx
);
2397 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2399 static void ctx_sched_out(struct perf_event_context
*ctx
,
2400 struct perf_cpu_context
*cpuctx
,
2401 enum event_type_t event_type
)
2403 struct perf_event
*event
;
2404 int is_active
= ctx
->is_active
;
2406 ctx
->is_active
&= ~event_type
;
2407 if (likely(!ctx
->nr_events
))
2410 update_context_time(ctx
);
2411 update_cgrp_time_from_cpuctx(cpuctx
);
2412 if (!ctx
->nr_active
)
2415 perf_pmu_disable(ctx
->pmu
);
2416 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2417 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2418 group_sched_out(event
, cpuctx
, ctx
);
2421 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2422 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2423 group_sched_out(event
, cpuctx
, ctx
);
2425 perf_pmu_enable(ctx
->pmu
);
2429 * Test whether two contexts are equivalent, i.e. whether they have both been
2430 * cloned from the same version of the same context.
2432 * Equivalence is measured using a generation number in the context that is
2433 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2434 * and list_del_event().
2436 static int context_equiv(struct perf_event_context
*ctx1
,
2437 struct perf_event_context
*ctx2
)
2439 lockdep_assert_held(&ctx1
->lock
);
2440 lockdep_assert_held(&ctx2
->lock
);
2442 /* Pinning disables the swap optimization */
2443 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2446 /* If ctx1 is the parent of ctx2 */
2447 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2450 /* If ctx2 is the parent of ctx1 */
2451 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2455 * If ctx1 and ctx2 have the same parent; we flatten the parent
2456 * hierarchy, see perf_event_init_context().
2458 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2459 ctx1
->parent_gen
== ctx2
->parent_gen
)
2466 static void __perf_event_sync_stat(struct perf_event
*event
,
2467 struct perf_event
*next_event
)
2471 if (!event
->attr
.inherit_stat
)
2475 * Update the event value, we cannot use perf_event_read()
2476 * because we're in the middle of a context switch and have IRQs
2477 * disabled, which upsets smp_call_function_single(), however
2478 * we know the event must be on the current CPU, therefore we
2479 * don't need to use it.
2481 switch (event
->state
) {
2482 case PERF_EVENT_STATE_ACTIVE
:
2483 event
->pmu
->read(event
);
2486 case PERF_EVENT_STATE_INACTIVE
:
2487 update_event_times(event
);
2495 * In order to keep per-task stats reliable we need to flip the event
2496 * values when we flip the contexts.
2498 value
= local64_read(&next_event
->count
);
2499 value
= local64_xchg(&event
->count
, value
);
2500 local64_set(&next_event
->count
, value
);
2502 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2503 swap(event
->total_time_running
, next_event
->total_time_running
);
2506 * Since we swizzled the values, update the user visible data too.
2508 perf_event_update_userpage(event
);
2509 perf_event_update_userpage(next_event
);
2512 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2513 struct perf_event_context
*next_ctx
)
2515 struct perf_event
*event
, *next_event
;
2520 update_context_time(ctx
);
2522 event
= list_first_entry(&ctx
->event_list
,
2523 struct perf_event
, event_entry
);
2525 next_event
= list_first_entry(&next_ctx
->event_list
,
2526 struct perf_event
, event_entry
);
2528 while (&event
->event_entry
!= &ctx
->event_list
&&
2529 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2531 __perf_event_sync_stat(event
, next_event
);
2533 event
= list_next_entry(event
, event_entry
);
2534 next_event
= list_next_entry(next_event
, event_entry
);
2538 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2539 struct task_struct
*next
)
2541 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2542 struct perf_event_context
*next_ctx
;
2543 struct perf_event_context
*parent
, *next_parent
;
2544 struct perf_cpu_context
*cpuctx
;
2550 cpuctx
= __get_cpu_context(ctx
);
2551 if (!cpuctx
->task_ctx
)
2555 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2559 parent
= rcu_dereference(ctx
->parent_ctx
);
2560 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2562 /* If neither context have a parent context; they cannot be clones. */
2563 if (!parent
&& !next_parent
)
2566 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2568 * Looks like the two contexts are clones, so we might be
2569 * able to optimize the context switch. We lock both
2570 * contexts and check that they are clones under the
2571 * lock (including re-checking that neither has been
2572 * uncloned in the meantime). It doesn't matter which
2573 * order we take the locks because no other cpu could
2574 * be trying to lock both of these tasks.
2576 raw_spin_lock(&ctx
->lock
);
2577 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2578 if (context_equiv(ctx
, next_ctx
)) {
2580 * XXX do we need a memory barrier of sorts
2581 * wrt to rcu_dereference() of perf_event_ctxp
2583 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2584 next
->perf_event_ctxp
[ctxn
] = ctx
;
2586 next_ctx
->task
= task
;
2588 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2592 perf_event_sync_stat(ctx
, next_ctx
);
2594 raw_spin_unlock(&next_ctx
->lock
);
2595 raw_spin_unlock(&ctx
->lock
);
2601 raw_spin_lock(&ctx
->lock
);
2602 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2603 cpuctx
->task_ctx
= NULL
;
2604 raw_spin_unlock(&ctx
->lock
);
2608 void perf_sched_cb_dec(struct pmu
*pmu
)
2610 this_cpu_dec(perf_sched_cb_usages
);
2613 void perf_sched_cb_inc(struct pmu
*pmu
)
2615 this_cpu_inc(perf_sched_cb_usages
);
2619 * This function provides the context switch callback to the lower code
2620 * layer. It is invoked ONLY when the context switch callback is enabled.
2622 static void perf_pmu_sched_task(struct task_struct
*prev
,
2623 struct task_struct
*next
,
2626 struct perf_cpu_context
*cpuctx
;
2628 unsigned long flags
;
2633 local_irq_save(flags
);
2637 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2638 if (pmu
->sched_task
) {
2639 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2641 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2643 perf_pmu_disable(pmu
);
2645 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2647 perf_pmu_enable(pmu
);
2649 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2655 local_irq_restore(flags
);
2658 static void perf_event_switch(struct task_struct
*task
,
2659 struct task_struct
*next_prev
, bool sched_in
);
2661 #define for_each_task_context_nr(ctxn) \
2662 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2665 * Called from scheduler to remove the events of the current task,
2666 * with interrupts disabled.
2668 * We stop each event and update the event value in event->count.
2670 * This does not protect us against NMI, but disable()
2671 * sets the disabled bit in the control field of event _before_
2672 * accessing the event control register. If a NMI hits, then it will
2673 * not restart the event.
2675 void __perf_event_task_sched_out(struct task_struct
*task
,
2676 struct task_struct
*next
)
2680 if (__this_cpu_read(perf_sched_cb_usages
))
2681 perf_pmu_sched_task(task
, next
, false);
2683 if (atomic_read(&nr_switch_events
))
2684 perf_event_switch(task
, next
, false);
2686 for_each_task_context_nr(ctxn
)
2687 perf_event_context_sched_out(task
, ctxn
, next
);
2690 * if cgroup events exist on this CPU, then we need
2691 * to check if we have to switch out PMU state.
2692 * cgroup event are system-wide mode only
2694 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2695 perf_cgroup_sched_out(task
, next
);
2698 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2700 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2702 if (!cpuctx
->task_ctx
)
2705 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2708 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2709 cpuctx
->task_ctx
= NULL
;
2713 * Called with IRQs disabled
2715 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2716 enum event_type_t event_type
)
2718 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2722 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2723 struct perf_cpu_context
*cpuctx
)
2725 struct perf_event
*event
;
2727 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2728 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2730 if (!event_filter_match(event
))
2733 /* may need to reset tstamp_enabled */
2734 if (is_cgroup_event(event
))
2735 perf_cgroup_mark_enabled(event
, ctx
);
2737 if (group_can_go_on(event
, cpuctx
, 1))
2738 group_sched_in(event
, cpuctx
, ctx
);
2741 * If this pinned group hasn't been scheduled,
2742 * put it in error state.
2744 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2745 update_group_times(event
);
2746 event
->state
= PERF_EVENT_STATE_ERROR
;
2752 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2753 struct perf_cpu_context
*cpuctx
)
2755 struct perf_event
*event
;
2758 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2759 /* Ignore events in OFF or ERROR state */
2760 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2763 * Listen to the 'cpu' scheduling filter constraint
2766 if (!event_filter_match(event
))
2769 /* may need to reset tstamp_enabled */
2770 if (is_cgroup_event(event
))
2771 perf_cgroup_mark_enabled(event
, ctx
);
2773 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2774 if (group_sched_in(event
, cpuctx
, ctx
))
2781 ctx_sched_in(struct perf_event_context
*ctx
,
2782 struct perf_cpu_context
*cpuctx
,
2783 enum event_type_t event_type
,
2784 struct task_struct
*task
)
2787 int is_active
= ctx
->is_active
;
2789 ctx
->is_active
|= event_type
;
2790 if (likely(!ctx
->nr_events
))
2794 ctx
->timestamp
= now
;
2795 perf_cgroup_set_timestamp(task
, ctx
);
2797 * First go through the list and put on any pinned groups
2798 * in order to give them the best chance of going on.
2800 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2801 ctx_pinned_sched_in(ctx
, cpuctx
);
2803 /* Then walk through the lower prio flexible groups */
2804 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2805 ctx_flexible_sched_in(ctx
, cpuctx
);
2808 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2809 enum event_type_t event_type
,
2810 struct task_struct
*task
)
2812 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2814 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2817 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2818 struct task_struct
*task
)
2820 struct perf_cpu_context
*cpuctx
;
2822 cpuctx
= __get_cpu_context(ctx
);
2823 if (cpuctx
->task_ctx
== ctx
)
2826 perf_ctx_lock(cpuctx
, ctx
);
2827 perf_pmu_disable(ctx
->pmu
);
2829 * We want to keep the following priority order:
2830 * cpu pinned (that don't need to move), task pinned,
2831 * cpu flexible, task flexible.
2833 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2836 cpuctx
->task_ctx
= ctx
;
2838 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2840 perf_pmu_enable(ctx
->pmu
);
2841 perf_ctx_unlock(cpuctx
, ctx
);
2845 * Called from scheduler to add the events of the current task
2846 * with interrupts disabled.
2848 * We restore the event value and then enable it.
2850 * This does not protect us against NMI, but enable()
2851 * sets the enabled bit in the control field of event _before_
2852 * accessing the event control register. If a NMI hits, then it will
2853 * keep the event running.
2855 void __perf_event_task_sched_in(struct task_struct
*prev
,
2856 struct task_struct
*task
)
2858 struct perf_event_context
*ctx
;
2861 for_each_task_context_nr(ctxn
) {
2862 ctx
= task
->perf_event_ctxp
[ctxn
];
2866 perf_event_context_sched_in(ctx
, task
);
2869 * if cgroup events exist on this CPU, then we need
2870 * to check if we have to switch in PMU state.
2871 * cgroup event are system-wide mode only
2873 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2874 perf_cgroup_sched_in(prev
, task
);
2876 if (atomic_read(&nr_switch_events
))
2877 perf_event_switch(task
, prev
, true);
2879 if (__this_cpu_read(perf_sched_cb_usages
))
2880 perf_pmu_sched_task(prev
, task
, true);
2883 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2885 u64 frequency
= event
->attr
.sample_freq
;
2886 u64 sec
= NSEC_PER_SEC
;
2887 u64 divisor
, dividend
;
2889 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2891 count_fls
= fls64(count
);
2892 nsec_fls
= fls64(nsec
);
2893 frequency_fls
= fls64(frequency
);
2897 * We got @count in @nsec, with a target of sample_freq HZ
2898 * the target period becomes:
2901 * period = -------------------
2902 * @nsec * sample_freq
2907 * Reduce accuracy by one bit such that @a and @b converge
2908 * to a similar magnitude.
2910 #define REDUCE_FLS(a, b) \
2912 if (a##_fls > b##_fls) { \
2922 * Reduce accuracy until either term fits in a u64, then proceed with
2923 * the other, so that finally we can do a u64/u64 division.
2925 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2926 REDUCE_FLS(nsec
, frequency
);
2927 REDUCE_FLS(sec
, count
);
2930 if (count_fls
+ sec_fls
> 64) {
2931 divisor
= nsec
* frequency
;
2933 while (count_fls
+ sec_fls
> 64) {
2934 REDUCE_FLS(count
, sec
);
2938 dividend
= count
* sec
;
2940 dividend
= count
* sec
;
2942 while (nsec_fls
+ frequency_fls
> 64) {
2943 REDUCE_FLS(nsec
, frequency
);
2947 divisor
= nsec
* frequency
;
2953 return div64_u64(dividend
, divisor
);
2956 static DEFINE_PER_CPU(int, perf_throttled_count
);
2957 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2959 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2961 struct hw_perf_event
*hwc
= &event
->hw
;
2962 s64 period
, sample_period
;
2965 period
= perf_calculate_period(event
, nsec
, count
);
2967 delta
= (s64
)(period
- hwc
->sample_period
);
2968 delta
= (delta
+ 7) / 8; /* low pass filter */
2970 sample_period
= hwc
->sample_period
+ delta
;
2975 hwc
->sample_period
= sample_period
;
2977 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2979 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2981 local64_set(&hwc
->period_left
, 0);
2984 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2989 * combine freq adjustment with unthrottling to avoid two passes over the
2990 * events. At the same time, make sure, having freq events does not change
2991 * the rate of unthrottling as that would introduce bias.
2993 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2996 struct perf_event
*event
;
2997 struct hw_perf_event
*hwc
;
2998 u64 now
, period
= TICK_NSEC
;
3002 * only need to iterate over all events iff:
3003 * - context have events in frequency mode (needs freq adjust)
3004 * - there are events to unthrottle on this cpu
3006 if (!(ctx
->nr_freq
|| needs_unthr
))
3009 raw_spin_lock(&ctx
->lock
);
3010 perf_pmu_disable(ctx
->pmu
);
3012 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3013 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3016 if (!event_filter_match(event
))
3019 perf_pmu_disable(event
->pmu
);
3023 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3024 hwc
->interrupts
= 0;
3025 perf_log_throttle(event
, 1);
3026 event
->pmu
->start(event
, 0);
3029 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3033 * stop the event and update event->count
3035 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3037 now
= local64_read(&event
->count
);
3038 delta
= now
- hwc
->freq_count_stamp
;
3039 hwc
->freq_count_stamp
= now
;
3043 * reload only if value has changed
3044 * we have stopped the event so tell that
3045 * to perf_adjust_period() to avoid stopping it
3049 perf_adjust_period(event
, period
, delta
, false);
3051 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3053 perf_pmu_enable(event
->pmu
);
3056 perf_pmu_enable(ctx
->pmu
);
3057 raw_spin_unlock(&ctx
->lock
);
3061 * Round-robin a context's events:
3063 static void rotate_ctx(struct perf_event_context
*ctx
)
3066 * Rotate the first entry last of non-pinned groups. Rotation might be
3067 * disabled by the inheritance code.
3069 if (!ctx
->rotate_disable
)
3070 list_rotate_left(&ctx
->flexible_groups
);
3073 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3075 struct perf_event_context
*ctx
= NULL
;
3078 if (cpuctx
->ctx
.nr_events
) {
3079 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3083 ctx
= cpuctx
->task_ctx
;
3084 if (ctx
&& ctx
->nr_events
) {
3085 if (ctx
->nr_events
!= ctx
->nr_active
)
3092 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3093 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3095 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3097 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3099 rotate_ctx(&cpuctx
->ctx
);
3103 perf_event_sched_in(cpuctx
, ctx
, current
);
3105 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3106 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3112 #ifdef CONFIG_NO_HZ_FULL
3113 bool perf_event_can_stop_tick(void)
3115 if (atomic_read(&nr_freq_events
) ||
3116 __this_cpu_read(perf_throttled_count
))
3123 void perf_event_task_tick(void)
3125 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3126 struct perf_event_context
*ctx
, *tmp
;
3129 WARN_ON(!irqs_disabled());
3131 __this_cpu_inc(perf_throttled_seq
);
3132 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3134 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3135 perf_adjust_freq_unthr_context(ctx
, throttled
);
3138 static int event_enable_on_exec(struct perf_event
*event
,
3139 struct perf_event_context
*ctx
)
3141 if (!event
->attr
.enable_on_exec
)
3144 event
->attr
.enable_on_exec
= 0;
3145 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3148 __perf_event_mark_enabled(event
);
3154 * Enable all of a task's events that have been marked enable-on-exec.
3155 * This expects task == current.
3157 static void perf_event_enable_on_exec(int ctxn
)
3159 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3160 struct perf_event
*event
;
3161 unsigned long flags
;
3165 local_irq_save(flags
);
3166 ctx
= current
->perf_event_ctxp
[ctxn
];
3167 if (!ctx
|| !ctx
->nr_events
)
3171 * We must ctxsw out cgroup events to avoid conflict
3172 * when invoking perf_task_event_sched_in() later on
3173 * in this function. Otherwise we end up trying to
3174 * ctxswin cgroup events which are already scheduled
3177 perf_cgroup_sched_out(current
, NULL
);
3179 raw_spin_lock(&ctx
->lock
);
3180 task_ctx_sched_out(ctx
);
3182 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3183 ret
= event_enable_on_exec(event
, ctx
);
3189 * Unclone this context if we enabled any event.
3192 clone_ctx
= unclone_ctx(ctx
);
3194 raw_spin_unlock(&ctx
->lock
);
3197 * Also calls ctxswin for cgroup events, if any:
3199 perf_event_context_sched_in(ctx
, ctx
->task
);
3201 local_irq_restore(flags
);
3207 void perf_event_exec(void)
3212 for_each_task_context_nr(ctxn
)
3213 perf_event_enable_on_exec(ctxn
);
3217 struct perf_read_data
{
3218 struct perf_event
*event
;
3224 * Cross CPU call to read the hardware event
3226 static void __perf_event_read(void *info
)
3228 struct perf_read_data
*data
= info
;
3229 struct perf_event
*sub
, *event
= data
->event
;
3230 struct perf_event_context
*ctx
= event
->ctx
;
3231 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3232 struct pmu
*pmu
= event
->pmu
;
3235 * If this is a task context, we need to check whether it is
3236 * the current task context of this cpu. If not it has been
3237 * scheduled out before the smp call arrived. In that case
3238 * event->count would have been updated to a recent sample
3239 * when the event was scheduled out.
3241 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3244 raw_spin_lock(&ctx
->lock
);
3245 if (ctx
->is_active
) {
3246 update_context_time(ctx
);
3247 update_cgrp_time_from_event(event
);
3250 update_event_times(event
);
3251 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3260 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3264 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3265 update_event_times(sub
);
3266 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3268 * Use sibling's PMU rather than @event's since
3269 * sibling could be on different (eg: software) PMU.
3271 sub
->pmu
->read(sub
);
3275 data
->ret
= pmu
->commit_txn(pmu
);
3278 raw_spin_unlock(&ctx
->lock
);
3281 static inline u64
perf_event_count(struct perf_event
*event
)
3283 if (event
->pmu
->count
)
3284 return event
->pmu
->count(event
);
3286 return __perf_event_count(event
);
3290 * NMI-safe method to read a local event, that is an event that
3292 * - either for the current task, or for this CPU
3293 * - does not have inherit set, for inherited task events
3294 * will not be local and we cannot read them atomically
3295 * - must not have a pmu::count method
3297 u64
perf_event_read_local(struct perf_event
*event
)
3299 unsigned long flags
;
3303 * Disabling interrupts avoids all counter scheduling (context
3304 * switches, timer based rotation and IPIs).
3306 local_irq_save(flags
);
3308 /* If this is a per-task event, it must be for current */
3309 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3310 event
->hw
.target
!= current
);
3312 /* If this is a per-CPU event, it must be for this CPU */
3313 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3314 event
->cpu
!= smp_processor_id());
3317 * It must not be an event with inherit set, we cannot read
3318 * all child counters from atomic context.
3320 WARN_ON_ONCE(event
->attr
.inherit
);
3323 * It must not have a pmu::count method, those are not
3326 WARN_ON_ONCE(event
->pmu
->count
);
3329 * If the event is currently on this CPU, its either a per-task event,
3330 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3333 if (event
->oncpu
== smp_processor_id())
3334 event
->pmu
->read(event
);
3336 val
= local64_read(&event
->count
);
3337 local_irq_restore(flags
);
3342 static int perf_event_read(struct perf_event
*event
, bool group
)
3347 * If event is enabled and currently active on a CPU, update the
3348 * value in the event structure:
3350 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3351 struct perf_read_data data
= {
3356 smp_call_function_single(event
->oncpu
,
3357 __perf_event_read
, &data
, 1);
3359 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3360 struct perf_event_context
*ctx
= event
->ctx
;
3361 unsigned long flags
;
3363 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3365 * may read while context is not active
3366 * (e.g., thread is blocked), in that case
3367 * we cannot update context time
3369 if (ctx
->is_active
) {
3370 update_context_time(ctx
);
3371 update_cgrp_time_from_event(event
);
3374 update_group_times(event
);
3376 update_event_times(event
);
3377 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3384 * Initialize the perf_event context in a task_struct:
3386 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3388 raw_spin_lock_init(&ctx
->lock
);
3389 mutex_init(&ctx
->mutex
);
3390 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3391 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3392 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3393 INIT_LIST_HEAD(&ctx
->event_list
);
3394 atomic_set(&ctx
->refcount
, 1);
3395 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3398 static struct perf_event_context
*
3399 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3401 struct perf_event_context
*ctx
;
3403 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3407 __perf_event_init_context(ctx
);
3410 get_task_struct(task
);
3417 static struct task_struct
*
3418 find_lively_task_by_vpid(pid_t vpid
)
3420 struct task_struct
*task
;
3427 task
= find_task_by_vpid(vpid
);
3429 get_task_struct(task
);
3433 return ERR_PTR(-ESRCH
);
3435 /* Reuse ptrace permission checks for now. */
3437 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3442 put_task_struct(task
);
3443 return ERR_PTR(err
);
3448 * Returns a matching context with refcount and pincount.
3450 static struct perf_event_context
*
3451 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3452 struct perf_event
*event
)
3454 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3455 struct perf_cpu_context
*cpuctx
;
3456 void *task_ctx_data
= NULL
;
3457 unsigned long flags
;
3459 int cpu
= event
->cpu
;
3462 /* Must be root to operate on a CPU event: */
3463 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3464 return ERR_PTR(-EACCES
);
3467 * We could be clever and allow to attach a event to an
3468 * offline CPU and activate it when the CPU comes up, but
3471 if (!cpu_online(cpu
))
3472 return ERR_PTR(-ENODEV
);
3474 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3483 ctxn
= pmu
->task_ctx_nr
;
3487 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3488 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3489 if (!task_ctx_data
) {
3496 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3498 clone_ctx
= unclone_ctx(ctx
);
3501 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3502 ctx
->task_ctx_data
= task_ctx_data
;
3503 task_ctx_data
= NULL
;
3505 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3510 ctx
= alloc_perf_context(pmu
, task
);
3515 if (task_ctx_data
) {
3516 ctx
->task_ctx_data
= task_ctx_data
;
3517 task_ctx_data
= NULL
;
3521 mutex_lock(&task
->perf_event_mutex
);
3523 * If it has already passed perf_event_exit_task().
3524 * we must see PF_EXITING, it takes this mutex too.
3526 if (task
->flags
& PF_EXITING
)
3528 else if (task
->perf_event_ctxp
[ctxn
])
3533 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3535 mutex_unlock(&task
->perf_event_mutex
);
3537 if (unlikely(err
)) {
3546 kfree(task_ctx_data
);
3550 kfree(task_ctx_data
);
3551 return ERR_PTR(err
);
3554 static void perf_event_free_filter(struct perf_event
*event
);
3555 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3557 static void free_event_rcu(struct rcu_head
*head
)
3559 struct perf_event
*event
;
3561 event
= container_of(head
, struct perf_event
, rcu_head
);
3563 put_pid_ns(event
->ns
);
3564 perf_event_free_filter(event
);
3568 static void ring_buffer_attach(struct perf_event
*event
,
3569 struct ring_buffer
*rb
);
3571 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3576 if (is_cgroup_event(event
))
3577 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3580 static void unaccount_event(struct perf_event
*event
)
3585 if (event
->attach_state
& PERF_ATTACH_TASK
)
3586 static_key_slow_dec_deferred(&perf_sched_events
);
3587 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3588 atomic_dec(&nr_mmap_events
);
3589 if (event
->attr
.comm
)
3590 atomic_dec(&nr_comm_events
);
3591 if (event
->attr
.task
)
3592 atomic_dec(&nr_task_events
);
3593 if (event
->attr
.freq
)
3594 atomic_dec(&nr_freq_events
);
3595 if (event
->attr
.context_switch
) {
3596 static_key_slow_dec_deferred(&perf_sched_events
);
3597 atomic_dec(&nr_switch_events
);
3599 if (is_cgroup_event(event
))
3600 static_key_slow_dec_deferred(&perf_sched_events
);
3601 if (has_branch_stack(event
))
3602 static_key_slow_dec_deferred(&perf_sched_events
);
3604 unaccount_event_cpu(event
, event
->cpu
);
3608 * The following implement mutual exclusion of events on "exclusive" pmus
3609 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3610 * at a time, so we disallow creating events that might conflict, namely:
3612 * 1) cpu-wide events in the presence of per-task events,
3613 * 2) per-task events in the presence of cpu-wide events,
3614 * 3) two matching events on the same context.
3616 * The former two cases are handled in the allocation path (perf_event_alloc(),
3617 * __free_event()), the latter -- before the first perf_install_in_context().
3619 static int exclusive_event_init(struct perf_event
*event
)
3621 struct pmu
*pmu
= event
->pmu
;
3623 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3627 * Prevent co-existence of per-task and cpu-wide events on the
3628 * same exclusive pmu.
3630 * Negative pmu::exclusive_cnt means there are cpu-wide
3631 * events on this "exclusive" pmu, positive means there are
3634 * Since this is called in perf_event_alloc() path, event::ctx
3635 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3636 * to mean "per-task event", because unlike other attach states it
3637 * never gets cleared.
3639 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3640 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3643 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3650 static void exclusive_event_destroy(struct perf_event
*event
)
3652 struct pmu
*pmu
= event
->pmu
;
3654 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3657 /* see comment in exclusive_event_init() */
3658 if (event
->attach_state
& PERF_ATTACH_TASK
)
3659 atomic_dec(&pmu
->exclusive_cnt
);
3661 atomic_inc(&pmu
->exclusive_cnt
);
3664 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3666 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3667 (e1
->cpu
== e2
->cpu
||
3674 /* Called under the same ctx::mutex as perf_install_in_context() */
3675 static bool exclusive_event_installable(struct perf_event
*event
,
3676 struct perf_event_context
*ctx
)
3678 struct perf_event
*iter_event
;
3679 struct pmu
*pmu
= event
->pmu
;
3681 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3684 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3685 if (exclusive_event_match(iter_event
, event
))
3692 static void __free_event(struct perf_event
*event
)
3694 if (!event
->parent
) {
3695 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3696 put_callchain_buffers();
3699 perf_event_free_bpf_prog(event
);
3702 event
->destroy(event
);
3705 put_ctx(event
->ctx
);
3708 exclusive_event_destroy(event
);
3709 module_put(event
->pmu
->module
);
3712 call_rcu(&event
->rcu_head
, free_event_rcu
);
3715 static void _free_event(struct perf_event
*event
)
3717 irq_work_sync(&event
->pending
);
3719 unaccount_event(event
);
3723 * Can happen when we close an event with re-directed output.
3725 * Since we have a 0 refcount, perf_mmap_close() will skip
3726 * over us; possibly making our ring_buffer_put() the last.
3728 mutex_lock(&event
->mmap_mutex
);
3729 ring_buffer_attach(event
, NULL
);
3730 mutex_unlock(&event
->mmap_mutex
);
3733 if (is_cgroup_event(event
))
3734 perf_detach_cgroup(event
);
3736 __free_event(event
);
3740 * Used to free events which have a known refcount of 1, such as in error paths
3741 * where the event isn't exposed yet and inherited events.
3743 static void free_event(struct perf_event
*event
)
3745 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3746 "unexpected event refcount: %ld; ptr=%p\n",
3747 atomic_long_read(&event
->refcount
), event
)) {
3748 /* leak to avoid use-after-free */
3756 * Remove user event from the owner task.
3758 static void perf_remove_from_owner(struct perf_event
*event
)
3760 struct task_struct
*owner
;
3763 owner
= ACCESS_ONCE(event
->owner
);
3765 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3766 * !owner it means the list deletion is complete and we can indeed
3767 * free this event, otherwise we need to serialize on
3768 * owner->perf_event_mutex.
3770 smp_read_barrier_depends();
3773 * Since delayed_put_task_struct() also drops the last
3774 * task reference we can safely take a new reference
3775 * while holding the rcu_read_lock().
3777 get_task_struct(owner
);
3783 * If we're here through perf_event_exit_task() we're already
3784 * holding ctx->mutex which would be an inversion wrt. the
3785 * normal lock order.
3787 * However we can safely take this lock because its the child
3790 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3793 * We have to re-check the event->owner field, if it is cleared
3794 * we raced with perf_event_exit_task(), acquiring the mutex
3795 * ensured they're done, and we can proceed with freeing the
3799 list_del_init(&event
->owner_entry
);
3800 mutex_unlock(&owner
->perf_event_mutex
);
3801 put_task_struct(owner
);
3805 static void put_event(struct perf_event
*event
)
3807 struct perf_event_context
*ctx
;
3809 if (!atomic_long_dec_and_test(&event
->refcount
))
3812 if (!is_kernel_event(event
))
3813 perf_remove_from_owner(event
);
3816 * There are two ways this annotation is useful:
3818 * 1) there is a lock recursion from perf_event_exit_task
3819 * see the comment there.
3821 * 2) there is a lock-inversion with mmap_sem through
3822 * perf_read_group(), which takes faults while
3823 * holding ctx->mutex, however this is called after
3824 * the last filedesc died, so there is no possibility
3825 * to trigger the AB-BA case.
3827 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3828 WARN_ON_ONCE(ctx
->parent_ctx
);
3829 perf_remove_from_context(event
, true);
3830 perf_event_ctx_unlock(event
, ctx
);
3835 int perf_event_release_kernel(struct perf_event
*event
)
3840 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3843 * Called when the last reference to the file is gone.
3845 static int perf_release(struct inode
*inode
, struct file
*file
)
3847 put_event(file
->private_data
);
3852 * Remove all orphanes events from the context.
3854 static void orphans_remove_work(struct work_struct
*work
)
3856 struct perf_event_context
*ctx
;
3857 struct perf_event
*event
, *tmp
;
3859 ctx
= container_of(work
, struct perf_event_context
,
3860 orphans_remove
.work
);
3862 mutex_lock(&ctx
->mutex
);
3863 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3864 struct perf_event
*parent_event
= event
->parent
;
3866 if (!is_orphaned_child(event
))
3869 perf_remove_from_context(event
, true);
3871 mutex_lock(&parent_event
->child_mutex
);
3872 list_del_init(&event
->child_list
);
3873 mutex_unlock(&parent_event
->child_mutex
);
3876 put_event(parent_event
);
3879 raw_spin_lock_irq(&ctx
->lock
);
3880 ctx
->orphans_remove_sched
= false;
3881 raw_spin_unlock_irq(&ctx
->lock
);
3882 mutex_unlock(&ctx
->mutex
);
3887 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3889 struct perf_event
*child
;
3895 mutex_lock(&event
->child_mutex
);
3897 (void)perf_event_read(event
, false);
3898 total
+= perf_event_count(event
);
3900 *enabled
+= event
->total_time_enabled
+
3901 atomic64_read(&event
->child_total_time_enabled
);
3902 *running
+= event
->total_time_running
+
3903 atomic64_read(&event
->child_total_time_running
);
3905 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3906 (void)perf_event_read(child
, false);
3907 total
+= perf_event_count(child
);
3908 *enabled
+= child
->total_time_enabled
;
3909 *running
+= child
->total_time_running
;
3911 mutex_unlock(&event
->child_mutex
);
3915 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3917 static int __perf_read_group_add(struct perf_event
*leader
,
3918 u64 read_format
, u64
*values
)
3920 struct perf_event
*sub
;
3921 int n
= 1; /* skip @nr */
3924 ret
= perf_event_read(leader
, true);
3929 * Since we co-schedule groups, {enabled,running} times of siblings
3930 * will be identical to those of the leader, so we only publish one
3933 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3934 values
[n
++] += leader
->total_time_enabled
+
3935 atomic64_read(&leader
->child_total_time_enabled
);
3938 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3939 values
[n
++] += leader
->total_time_running
+
3940 atomic64_read(&leader
->child_total_time_running
);
3944 * Write {count,id} tuples for every sibling.
3946 values
[n
++] += perf_event_count(leader
);
3947 if (read_format
& PERF_FORMAT_ID
)
3948 values
[n
++] = primary_event_id(leader
);
3950 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3951 values
[n
++] += perf_event_count(sub
);
3952 if (read_format
& PERF_FORMAT_ID
)
3953 values
[n
++] = primary_event_id(sub
);
3959 static int perf_read_group(struct perf_event
*event
,
3960 u64 read_format
, char __user
*buf
)
3962 struct perf_event
*leader
= event
->group_leader
, *child
;
3963 struct perf_event_context
*ctx
= leader
->ctx
;
3967 lockdep_assert_held(&ctx
->mutex
);
3969 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3973 values
[0] = 1 + leader
->nr_siblings
;
3976 * By locking the child_mutex of the leader we effectively
3977 * lock the child list of all siblings.. XXX explain how.
3979 mutex_lock(&leader
->child_mutex
);
3981 ret
= __perf_read_group_add(leader
, read_format
, values
);
3985 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3986 ret
= __perf_read_group_add(child
, read_format
, values
);
3991 mutex_unlock(&leader
->child_mutex
);
3993 ret
= event
->read_size
;
3994 if (copy_to_user(buf
, values
, event
->read_size
))
3999 mutex_unlock(&leader
->child_mutex
);
4005 static int perf_read_one(struct perf_event
*event
,
4006 u64 read_format
, char __user
*buf
)
4008 u64 enabled
, running
;
4012 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4013 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4014 values
[n
++] = enabled
;
4015 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4016 values
[n
++] = running
;
4017 if (read_format
& PERF_FORMAT_ID
)
4018 values
[n
++] = primary_event_id(event
);
4020 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4023 return n
* sizeof(u64
);
4026 static bool is_event_hup(struct perf_event
*event
)
4030 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
4033 mutex_lock(&event
->child_mutex
);
4034 no_children
= list_empty(&event
->child_list
);
4035 mutex_unlock(&event
->child_mutex
);
4040 * Read the performance event - simple non blocking version for now
4043 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4045 u64 read_format
= event
->attr
.read_format
;
4049 * Return end-of-file for a read on a event that is in
4050 * error state (i.e. because it was pinned but it couldn't be
4051 * scheduled on to the CPU at some point).
4053 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4056 if (count
< event
->read_size
)
4059 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4060 if (read_format
& PERF_FORMAT_GROUP
)
4061 ret
= perf_read_group(event
, read_format
, buf
);
4063 ret
= perf_read_one(event
, read_format
, buf
);
4069 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4071 struct perf_event
*event
= file
->private_data
;
4072 struct perf_event_context
*ctx
;
4075 ctx
= perf_event_ctx_lock(event
);
4076 ret
= __perf_read(event
, buf
, count
);
4077 perf_event_ctx_unlock(event
, ctx
);
4082 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4084 struct perf_event
*event
= file
->private_data
;
4085 struct ring_buffer
*rb
;
4086 unsigned int events
= POLLHUP
;
4088 poll_wait(file
, &event
->waitq
, wait
);
4090 if (is_event_hup(event
))
4094 * Pin the event->rb by taking event->mmap_mutex; otherwise
4095 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4097 mutex_lock(&event
->mmap_mutex
);
4100 events
= atomic_xchg(&rb
->poll
, 0);
4101 mutex_unlock(&event
->mmap_mutex
);
4105 static void _perf_event_reset(struct perf_event
*event
)
4107 (void)perf_event_read(event
, false);
4108 local64_set(&event
->count
, 0);
4109 perf_event_update_userpage(event
);
4113 * Holding the top-level event's child_mutex means that any
4114 * descendant process that has inherited this event will block
4115 * in sync_child_event if it goes to exit, thus satisfying the
4116 * task existence requirements of perf_event_enable/disable.
4118 static void perf_event_for_each_child(struct perf_event
*event
,
4119 void (*func
)(struct perf_event
*))
4121 struct perf_event
*child
;
4123 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4125 mutex_lock(&event
->child_mutex
);
4127 list_for_each_entry(child
, &event
->child_list
, child_list
)
4129 mutex_unlock(&event
->child_mutex
);
4132 static void perf_event_for_each(struct perf_event
*event
,
4133 void (*func
)(struct perf_event
*))
4135 struct perf_event_context
*ctx
= event
->ctx
;
4136 struct perf_event
*sibling
;
4138 lockdep_assert_held(&ctx
->mutex
);
4140 event
= event
->group_leader
;
4142 perf_event_for_each_child(event
, func
);
4143 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4144 perf_event_for_each_child(sibling
, func
);
4147 struct period_event
{
4148 struct perf_event
*event
;
4152 static int __perf_event_period(void *info
)
4154 struct period_event
*pe
= info
;
4155 struct perf_event
*event
= pe
->event
;
4156 struct perf_event_context
*ctx
= event
->ctx
;
4157 u64 value
= pe
->value
;
4160 raw_spin_lock(&ctx
->lock
);
4161 if (event
->attr
.freq
) {
4162 event
->attr
.sample_freq
= value
;
4164 event
->attr
.sample_period
= value
;
4165 event
->hw
.sample_period
= value
;
4168 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4170 perf_pmu_disable(ctx
->pmu
);
4171 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4174 local64_set(&event
->hw
.period_left
, 0);
4177 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4178 perf_pmu_enable(ctx
->pmu
);
4180 raw_spin_unlock(&ctx
->lock
);
4185 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4187 struct period_event pe
= { .event
= event
, };
4188 struct perf_event_context
*ctx
= event
->ctx
;
4189 struct task_struct
*task
;
4192 if (!is_sampling_event(event
))
4195 if (copy_from_user(&value
, arg
, sizeof(value
)))
4201 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4208 cpu_function_call(event
->cpu
, __perf_event_period
, &pe
);
4213 if (!task_function_call(task
, __perf_event_period
, &pe
))
4216 raw_spin_lock_irq(&ctx
->lock
);
4217 if (ctx
->is_active
) {
4218 raw_spin_unlock_irq(&ctx
->lock
);
4223 if (event
->attr
.freq
) {
4224 event
->attr
.sample_freq
= value
;
4226 event
->attr
.sample_period
= value
;
4227 event
->hw
.sample_period
= value
;
4230 local64_set(&event
->hw
.period_left
, 0);
4231 raw_spin_unlock_irq(&ctx
->lock
);
4236 static const struct file_operations perf_fops
;
4238 static inline int perf_fget_light(int fd
, struct fd
*p
)
4240 struct fd f
= fdget(fd
);
4244 if (f
.file
->f_op
!= &perf_fops
) {
4252 static int perf_event_set_output(struct perf_event
*event
,
4253 struct perf_event
*output_event
);
4254 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4255 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4257 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4259 void (*func
)(struct perf_event
*);
4263 case PERF_EVENT_IOC_ENABLE
:
4264 func
= _perf_event_enable
;
4266 case PERF_EVENT_IOC_DISABLE
:
4267 func
= _perf_event_disable
;
4269 case PERF_EVENT_IOC_RESET
:
4270 func
= _perf_event_reset
;
4273 case PERF_EVENT_IOC_REFRESH
:
4274 return _perf_event_refresh(event
, arg
);
4276 case PERF_EVENT_IOC_PERIOD
:
4277 return perf_event_period(event
, (u64 __user
*)arg
);
4279 case PERF_EVENT_IOC_ID
:
4281 u64 id
= primary_event_id(event
);
4283 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4288 case PERF_EVENT_IOC_SET_OUTPUT
:
4292 struct perf_event
*output_event
;
4294 ret
= perf_fget_light(arg
, &output
);
4297 output_event
= output
.file
->private_data
;
4298 ret
= perf_event_set_output(event
, output_event
);
4301 ret
= perf_event_set_output(event
, NULL
);
4306 case PERF_EVENT_IOC_SET_FILTER
:
4307 return perf_event_set_filter(event
, (void __user
*)arg
);
4309 case PERF_EVENT_IOC_SET_BPF
:
4310 return perf_event_set_bpf_prog(event
, arg
);
4316 if (flags
& PERF_IOC_FLAG_GROUP
)
4317 perf_event_for_each(event
, func
);
4319 perf_event_for_each_child(event
, func
);
4324 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4326 struct perf_event
*event
= file
->private_data
;
4327 struct perf_event_context
*ctx
;
4330 ctx
= perf_event_ctx_lock(event
);
4331 ret
= _perf_ioctl(event
, cmd
, arg
);
4332 perf_event_ctx_unlock(event
, ctx
);
4337 #ifdef CONFIG_COMPAT
4338 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4341 switch (_IOC_NR(cmd
)) {
4342 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4343 case _IOC_NR(PERF_EVENT_IOC_ID
):
4344 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4345 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4346 cmd
&= ~IOCSIZE_MASK
;
4347 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4351 return perf_ioctl(file
, cmd
, arg
);
4354 # define perf_compat_ioctl NULL
4357 int perf_event_task_enable(void)
4359 struct perf_event_context
*ctx
;
4360 struct perf_event
*event
;
4362 mutex_lock(¤t
->perf_event_mutex
);
4363 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4364 ctx
= perf_event_ctx_lock(event
);
4365 perf_event_for_each_child(event
, _perf_event_enable
);
4366 perf_event_ctx_unlock(event
, ctx
);
4368 mutex_unlock(¤t
->perf_event_mutex
);
4373 int perf_event_task_disable(void)
4375 struct perf_event_context
*ctx
;
4376 struct perf_event
*event
;
4378 mutex_lock(¤t
->perf_event_mutex
);
4379 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4380 ctx
= perf_event_ctx_lock(event
);
4381 perf_event_for_each_child(event
, _perf_event_disable
);
4382 perf_event_ctx_unlock(event
, ctx
);
4384 mutex_unlock(¤t
->perf_event_mutex
);
4389 static int perf_event_index(struct perf_event
*event
)
4391 if (event
->hw
.state
& PERF_HES_STOPPED
)
4394 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4397 return event
->pmu
->event_idx(event
);
4400 static void calc_timer_values(struct perf_event
*event
,
4407 *now
= perf_clock();
4408 ctx_time
= event
->shadow_ctx_time
+ *now
;
4409 *enabled
= ctx_time
- event
->tstamp_enabled
;
4410 *running
= ctx_time
- event
->tstamp_running
;
4413 static void perf_event_init_userpage(struct perf_event
*event
)
4415 struct perf_event_mmap_page
*userpg
;
4416 struct ring_buffer
*rb
;
4419 rb
= rcu_dereference(event
->rb
);
4423 userpg
= rb
->user_page
;
4425 /* Allow new userspace to detect that bit 0 is deprecated */
4426 userpg
->cap_bit0_is_deprecated
= 1;
4427 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4428 userpg
->data_offset
= PAGE_SIZE
;
4429 userpg
->data_size
= perf_data_size(rb
);
4435 void __weak
arch_perf_update_userpage(
4436 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4441 * Callers need to ensure there can be no nesting of this function, otherwise
4442 * the seqlock logic goes bad. We can not serialize this because the arch
4443 * code calls this from NMI context.
4445 void perf_event_update_userpage(struct perf_event
*event
)
4447 struct perf_event_mmap_page
*userpg
;
4448 struct ring_buffer
*rb
;
4449 u64 enabled
, running
, now
;
4452 rb
= rcu_dereference(event
->rb
);
4457 * compute total_time_enabled, total_time_running
4458 * based on snapshot values taken when the event
4459 * was last scheduled in.
4461 * we cannot simply called update_context_time()
4462 * because of locking issue as we can be called in
4465 calc_timer_values(event
, &now
, &enabled
, &running
);
4467 userpg
= rb
->user_page
;
4469 * Disable preemption so as to not let the corresponding user-space
4470 * spin too long if we get preempted.
4475 userpg
->index
= perf_event_index(event
);
4476 userpg
->offset
= perf_event_count(event
);
4478 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4480 userpg
->time_enabled
= enabled
+
4481 atomic64_read(&event
->child_total_time_enabled
);
4483 userpg
->time_running
= running
+
4484 atomic64_read(&event
->child_total_time_running
);
4486 arch_perf_update_userpage(event
, userpg
, now
);
4495 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4497 struct perf_event
*event
= vma
->vm_file
->private_data
;
4498 struct ring_buffer
*rb
;
4499 int ret
= VM_FAULT_SIGBUS
;
4501 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4502 if (vmf
->pgoff
== 0)
4508 rb
= rcu_dereference(event
->rb
);
4512 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4515 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4519 get_page(vmf
->page
);
4520 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4521 vmf
->page
->index
= vmf
->pgoff
;
4530 static void ring_buffer_attach(struct perf_event
*event
,
4531 struct ring_buffer
*rb
)
4533 struct ring_buffer
*old_rb
= NULL
;
4534 unsigned long flags
;
4538 * Should be impossible, we set this when removing
4539 * event->rb_entry and wait/clear when adding event->rb_entry.
4541 WARN_ON_ONCE(event
->rcu_pending
);
4544 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4545 list_del_rcu(&event
->rb_entry
);
4546 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4548 event
->rcu_batches
= get_state_synchronize_rcu();
4549 event
->rcu_pending
= 1;
4553 if (event
->rcu_pending
) {
4554 cond_synchronize_rcu(event
->rcu_batches
);
4555 event
->rcu_pending
= 0;
4558 spin_lock_irqsave(&rb
->event_lock
, flags
);
4559 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4560 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4563 rcu_assign_pointer(event
->rb
, rb
);
4566 ring_buffer_put(old_rb
);
4568 * Since we detached before setting the new rb, so that we
4569 * could attach the new rb, we could have missed a wakeup.
4572 wake_up_all(&event
->waitq
);
4576 static void ring_buffer_wakeup(struct perf_event
*event
)
4578 struct ring_buffer
*rb
;
4581 rb
= rcu_dereference(event
->rb
);
4583 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4584 wake_up_all(&event
->waitq
);
4589 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4591 struct ring_buffer
*rb
;
4594 rb
= rcu_dereference(event
->rb
);
4596 if (!atomic_inc_not_zero(&rb
->refcount
))
4604 void ring_buffer_put(struct ring_buffer
*rb
)
4606 if (!atomic_dec_and_test(&rb
->refcount
))
4609 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4611 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4614 static void perf_mmap_open(struct vm_area_struct
*vma
)
4616 struct perf_event
*event
= vma
->vm_file
->private_data
;
4618 atomic_inc(&event
->mmap_count
);
4619 atomic_inc(&event
->rb
->mmap_count
);
4622 atomic_inc(&event
->rb
->aux_mmap_count
);
4624 if (event
->pmu
->event_mapped
)
4625 event
->pmu
->event_mapped(event
);
4629 * A buffer can be mmap()ed multiple times; either directly through the same
4630 * event, or through other events by use of perf_event_set_output().
4632 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4633 * the buffer here, where we still have a VM context. This means we need
4634 * to detach all events redirecting to us.
4636 static void perf_mmap_close(struct vm_area_struct
*vma
)
4638 struct perf_event
*event
= vma
->vm_file
->private_data
;
4640 struct ring_buffer
*rb
= ring_buffer_get(event
);
4641 struct user_struct
*mmap_user
= rb
->mmap_user
;
4642 int mmap_locked
= rb
->mmap_locked
;
4643 unsigned long size
= perf_data_size(rb
);
4645 if (event
->pmu
->event_unmapped
)
4646 event
->pmu
->event_unmapped(event
);
4649 * rb->aux_mmap_count will always drop before rb->mmap_count and
4650 * event->mmap_count, so it is ok to use event->mmap_mutex to
4651 * serialize with perf_mmap here.
4653 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4654 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4655 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4656 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4659 mutex_unlock(&event
->mmap_mutex
);
4662 atomic_dec(&rb
->mmap_count
);
4664 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4667 ring_buffer_attach(event
, NULL
);
4668 mutex_unlock(&event
->mmap_mutex
);
4670 /* If there's still other mmap()s of this buffer, we're done. */
4671 if (atomic_read(&rb
->mmap_count
))
4675 * No other mmap()s, detach from all other events that might redirect
4676 * into the now unreachable buffer. Somewhat complicated by the
4677 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4681 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4682 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4684 * This event is en-route to free_event() which will
4685 * detach it and remove it from the list.
4691 mutex_lock(&event
->mmap_mutex
);
4693 * Check we didn't race with perf_event_set_output() which can
4694 * swizzle the rb from under us while we were waiting to
4695 * acquire mmap_mutex.
4697 * If we find a different rb; ignore this event, a next
4698 * iteration will no longer find it on the list. We have to
4699 * still restart the iteration to make sure we're not now
4700 * iterating the wrong list.
4702 if (event
->rb
== rb
)
4703 ring_buffer_attach(event
, NULL
);
4705 mutex_unlock(&event
->mmap_mutex
);
4709 * Restart the iteration; either we're on the wrong list or
4710 * destroyed its integrity by doing a deletion.
4717 * It could be there's still a few 0-ref events on the list; they'll
4718 * get cleaned up by free_event() -- they'll also still have their
4719 * ref on the rb and will free it whenever they are done with it.
4721 * Aside from that, this buffer is 'fully' detached and unmapped,
4722 * undo the VM accounting.
4725 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4726 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4727 free_uid(mmap_user
);
4730 ring_buffer_put(rb
); /* could be last */
4733 static const struct vm_operations_struct perf_mmap_vmops
= {
4734 .open
= perf_mmap_open
,
4735 .close
= perf_mmap_close
, /* non mergable */
4736 .fault
= perf_mmap_fault
,
4737 .page_mkwrite
= perf_mmap_fault
,
4740 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4742 struct perf_event
*event
= file
->private_data
;
4743 unsigned long user_locked
, user_lock_limit
;
4744 struct user_struct
*user
= current_user();
4745 unsigned long locked
, lock_limit
;
4746 struct ring_buffer
*rb
= NULL
;
4747 unsigned long vma_size
;
4748 unsigned long nr_pages
;
4749 long user_extra
= 0, extra
= 0;
4750 int ret
= 0, flags
= 0;
4753 * Don't allow mmap() of inherited per-task counters. This would
4754 * create a performance issue due to all children writing to the
4757 if (event
->cpu
== -1 && event
->attr
.inherit
)
4760 if (!(vma
->vm_flags
& VM_SHARED
))
4763 vma_size
= vma
->vm_end
- vma
->vm_start
;
4765 if (vma
->vm_pgoff
== 0) {
4766 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4769 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4770 * mapped, all subsequent mappings should have the same size
4771 * and offset. Must be above the normal perf buffer.
4773 u64 aux_offset
, aux_size
;
4778 nr_pages
= vma_size
/ PAGE_SIZE
;
4780 mutex_lock(&event
->mmap_mutex
);
4787 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4788 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4790 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4793 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4796 /* already mapped with a different offset */
4797 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4800 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4803 /* already mapped with a different size */
4804 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4807 if (!is_power_of_2(nr_pages
))
4810 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4813 if (rb_has_aux(rb
)) {
4814 atomic_inc(&rb
->aux_mmap_count
);
4819 atomic_set(&rb
->aux_mmap_count
, 1);
4820 user_extra
= nr_pages
;
4826 * If we have rb pages ensure they're a power-of-two number, so we
4827 * can do bitmasks instead of modulo.
4829 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4832 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4835 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4837 mutex_lock(&event
->mmap_mutex
);
4839 if (event
->rb
->nr_pages
!= nr_pages
) {
4844 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4846 * Raced against perf_mmap_close() through
4847 * perf_event_set_output(). Try again, hope for better
4850 mutex_unlock(&event
->mmap_mutex
);
4857 user_extra
= nr_pages
+ 1;
4860 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4863 * Increase the limit linearly with more CPUs:
4865 user_lock_limit
*= num_online_cpus();
4867 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4869 if (user_locked
> user_lock_limit
)
4870 extra
= user_locked
- user_lock_limit
;
4872 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4873 lock_limit
>>= PAGE_SHIFT
;
4874 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4876 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4877 !capable(CAP_IPC_LOCK
)) {
4882 WARN_ON(!rb
&& event
->rb
);
4884 if (vma
->vm_flags
& VM_WRITE
)
4885 flags
|= RING_BUFFER_WRITABLE
;
4888 rb
= rb_alloc(nr_pages
,
4889 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4897 atomic_set(&rb
->mmap_count
, 1);
4898 rb
->mmap_user
= get_current_user();
4899 rb
->mmap_locked
= extra
;
4901 ring_buffer_attach(event
, rb
);
4903 perf_event_init_userpage(event
);
4904 perf_event_update_userpage(event
);
4906 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4907 event
->attr
.aux_watermark
, flags
);
4909 rb
->aux_mmap_locked
= extra
;
4914 atomic_long_add(user_extra
, &user
->locked_vm
);
4915 vma
->vm_mm
->pinned_vm
+= extra
;
4917 atomic_inc(&event
->mmap_count
);
4919 atomic_dec(&rb
->mmap_count
);
4922 mutex_unlock(&event
->mmap_mutex
);
4925 * Since pinned accounting is per vm we cannot allow fork() to copy our
4928 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4929 vma
->vm_ops
= &perf_mmap_vmops
;
4931 if (event
->pmu
->event_mapped
)
4932 event
->pmu
->event_mapped(event
);
4937 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4939 struct inode
*inode
= file_inode(filp
);
4940 struct perf_event
*event
= filp
->private_data
;
4943 mutex_lock(&inode
->i_mutex
);
4944 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4945 mutex_unlock(&inode
->i_mutex
);
4953 static const struct file_operations perf_fops
= {
4954 .llseek
= no_llseek
,
4955 .release
= perf_release
,
4958 .unlocked_ioctl
= perf_ioctl
,
4959 .compat_ioctl
= perf_compat_ioctl
,
4961 .fasync
= perf_fasync
,
4967 * If there's data, ensure we set the poll() state and publish everything
4968 * to user-space before waking everybody up.
4971 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4973 /* only the parent has fasync state */
4975 event
= event
->parent
;
4976 return &event
->fasync
;
4979 void perf_event_wakeup(struct perf_event
*event
)
4981 ring_buffer_wakeup(event
);
4983 if (event
->pending_kill
) {
4984 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4985 event
->pending_kill
= 0;
4989 static void perf_pending_event(struct irq_work
*entry
)
4991 struct perf_event
*event
= container_of(entry
,
4992 struct perf_event
, pending
);
4995 rctx
= perf_swevent_get_recursion_context();
4997 * If we 'fail' here, that's OK, it means recursion is already disabled
4998 * and we won't recurse 'further'.
5001 if (event
->pending_disable
) {
5002 event
->pending_disable
= 0;
5003 __perf_event_disable(event
);
5006 if (event
->pending_wakeup
) {
5007 event
->pending_wakeup
= 0;
5008 perf_event_wakeup(event
);
5012 perf_swevent_put_recursion_context(rctx
);
5016 * We assume there is only KVM supporting the callbacks.
5017 * Later on, we might change it to a list if there is
5018 * another virtualization implementation supporting the callbacks.
5020 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5022 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5024 perf_guest_cbs
= cbs
;
5027 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5029 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5031 perf_guest_cbs
= NULL
;
5034 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5037 perf_output_sample_regs(struct perf_output_handle
*handle
,
5038 struct pt_regs
*regs
, u64 mask
)
5042 for_each_set_bit(bit
, (const unsigned long *) &mask
,
5043 sizeof(mask
) * BITS_PER_BYTE
) {
5046 val
= perf_reg_value(regs
, bit
);
5047 perf_output_put(handle
, val
);
5051 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5052 struct pt_regs
*regs
,
5053 struct pt_regs
*regs_user_copy
)
5055 if (user_mode(regs
)) {
5056 regs_user
->abi
= perf_reg_abi(current
);
5057 regs_user
->regs
= regs
;
5058 } else if (current
->mm
) {
5059 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5061 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5062 regs_user
->regs
= NULL
;
5066 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5067 struct pt_regs
*regs
)
5069 regs_intr
->regs
= regs
;
5070 regs_intr
->abi
= perf_reg_abi(current
);
5075 * Get remaining task size from user stack pointer.
5077 * It'd be better to take stack vma map and limit this more
5078 * precisly, but there's no way to get it safely under interrupt,
5079 * so using TASK_SIZE as limit.
5081 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5083 unsigned long addr
= perf_user_stack_pointer(regs
);
5085 if (!addr
|| addr
>= TASK_SIZE
)
5088 return TASK_SIZE
- addr
;
5092 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5093 struct pt_regs
*regs
)
5097 /* No regs, no stack pointer, no dump. */
5102 * Check if we fit in with the requested stack size into the:
5104 * If we don't, we limit the size to the TASK_SIZE.
5106 * - remaining sample size
5107 * If we don't, we customize the stack size to
5108 * fit in to the remaining sample size.
5111 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5112 stack_size
= min(stack_size
, (u16
) task_size
);
5114 /* Current header size plus static size and dynamic size. */
5115 header_size
+= 2 * sizeof(u64
);
5117 /* Do we fit in with the current stack dump size? */
5118 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5120 * If we overflow the maximum size for the sample,
5121 * we customize the stack dump size to fit in.
5123 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5124 stack_size
= round_up(stack_size
, sizeof(u64
));
5131 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5132 struct pt_regs
*regs
)
5134 /* Case of a kernel thread, nothing to dump */
5137 perf_output_put(handle
, size
);
5146 * - the size requested by user or the best one we can fit
5147 * in to the sample max size
5149 * - user stack dump data
5151 * - the actual dumped size
5155 perf_output_put(handle
, dump_size
);
5158 sp
= perf_user_stack_pointer(regs
);
5159 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5160 dyn_size
= dump_size
- rem
;
5162 perf_output_skip(handle
, rem
);
5165 perf_output_put(handle
, dyn_size
);
5169 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5170 struct perf_sample_data
*data
,
5171 struct perf_event
*event
)
5173 u64 sample_type
= event
->attr
.sample_type
;
5175 data
->type
= sample_type
;
5176 header
->size
+= event
->id_header_size
;
5178 if (sample_type
& PERF_SAMPLE_TID
) {
5179 /* namespace issues */
5180 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5181 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5184 if (sample_type
& PERF_SAMPLE_TIME
)
5185 data
->time
= perf_event_clock(event
);
5187 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5188 data
->id
= primary_event_id(event
);
5190 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5191 data
->stream_id
= event
->id
;
5193 if (sample_type
& PERF_SAMPLE_CPU
) {
5194 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5195 data
->cpu_entry
.reserved
= 0;
5199 void perf_event_header__init_id(struct perf_event_header
*header
,
5200 struct perf_sample_data
*data
,
5201 struct perf_event
*event
)
5203 if (event
->attr
.sample_id_all
)
5204 __perf_event_header__init_id(header
, data
, event
);
5207 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5208 struct perf_sample_data
*data
)
5210 u64 sample_type
= data
->type
;
5212 if (sample_type
& PERF_SAMPLE_TID
)
5213 perf_output_put(handle
, data
->tid_entry
);
5215 if (sample_type
& PERF_SAMPLE_TIME
)
5216 perf_output_put(handle
, data
->time
);
5218 if (sample_type
& PERF_SAMPLE_ID
)
5219 perf_output_put(handle
, data
->id
);
5221 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5222 perf_output_put(handle
, data
->stream_id
);
5224 if (sample_type
& PERF_SAMPLE_CPU
)
5225 perf_output_put(handle
, data
->cpu_entry
);
5227 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5228 perf_output_put(handle
, data
->id
);
5231 void perf_event__output_id_sample(struct perf_event
*event
,
5232 struct perf_output_handle
*handle
,
5233 struct perf_sample_data
*sample
)
5235 if (event
->attr
.sample_id_all
)
5236 __perf_event__output_id_sample(handle
, sample
);
5239 static void perf_output_read_one(struct perf_output_handle
*handle
,
5240 struct perf_event
*event
,
5241 u64 enabled
, u64 running
)
5243 u64 read_format
= event
->attr
.read_format
;
5247 values
[n
++] = perf_event_count(event
);
5248 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5249 values
[n
++] = enabled
+
5250 atomic64_read(&event
->child_total_time_enabled
);
5252 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5253 values
[n
++] = running
+
5254 atomic64_read(&event
->child_total_time_running
);
5256 if (read_format
& PERF_FORMAT_ID
)
5257 values
[n
++] = primary_event_id(event
);
5259 __output_copy(handle
, values
, n
* sizeof(u64
));
5263 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5265 static void perf_output_read_group(struct perf_output_handle
*handle
,
5266 struct perf_event
*event
,
5267 u64 enabled
, u64 running
)
5269 struct perf_event
*leader
= event
->group_leader
, *sub
;
5270 u64 read_format
= event
->attr
.read_format
;
5274 values
[n
++] = 1 + leader
->nr_siblings
;
5276 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5277 values
[n
++] = enabled
;
5279 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5280 values
[n
++] = running
;
5282 if (leader
!= event
)
5283 leader
->pmu
->read(leader
);
5285 values
[n
++] = perf_event_count(leader
);
5286 if (read_format
& PERF_FORMAT_ID
)
5287 values
[n
++] = primary_event_id(leader
);
5289 __output_copy(handle
, values
, n
* sizeof(u64
));
5291 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5294 if ((sub
!= event
) &&
5295 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5296 sub
->pmu
->read(sub
);
5298 values
[n
++] = perf_event_count(sub
);
5299 if (read_format
& PERF_FORMAT_ID
)
5300 values
[n
++] = primary_event_id(sub
);
5302 __output_copy(handle
, values
, n
* sizeof(u64
));
5306 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5307 PERF_FORMAT_TOTAL_TIME_RUNNING)
5309 static void perf_output_read(struct perf_output_handle
*handle
,
5310 struct perf_event
*event
)
5312 u64 enabled
= 0, running
= 0, now
;
5313 u64 read_format
= event
->attr
.read_format
;
5316 * compute total_time_enabled, total_time_running
5317 * based on snapshot values taken when the event
5318 * was last scheduled in.
5320 * we cannot simply called update_context_time()
5321 * because of locking issue as we are called in
5324 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5325 calc_timer_values(event
, &now
, &enabled
, &running
);
5327 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5328 perf_output_read_group(handle
, event
, enabled
, running
);
5330 perf_output_read_one(handle
, event
, enabled
, running
);
5333 void perf_output_sample(struct perf_output_handle
*handle
,
5334 struct perf_event_header
*header
,
5335 struct perf_sample_data
*data
,
5336 struct perf_event
*event
)
5338 u64 sample_type
= data
->type
;
5340 perf_output_put(handle
, *header
);
5342 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5343 perf_output_put(handle
, data
->id
);
5345 if (sample_type
& PERF_SAMPLE_IP
)
5346 perf_output_put(handle
, data
->ip
);
5348 if (sample_type
& PERF_SAMPLE_TID
)
5349 perf_output_put(handle
, data
->tid_entry
);
5351 if (sample_type
& PERF_SAMPLE_TIME
)
5352 perf_output_put(handle
, data
->time
);
5354 if (sample_type
& PERF_SAMPLE_ADDR
)
5355 perf_output_put(handle
, data
->addr
);
5357 if (sample_type
& PERF_SAMPLE_ID
)
5358 perf_output_put(handle
, data
->id
);
5360 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5361 perf_output_put(handle
, data
->stream_id
);
5363 if (sample_type
& PERF_SAMPLE_CPU
)
5364 perf_output_put(handle
, data
->cpu_entry
);
5366 if (sample_type
& PERF_SAMPLE_PERIOD
)
5367 perf_output_put(handle
, data
->period
);
5369 if (sample_type
& PERF_SAMPLE_READ
)
5370 perf_output_read(handle
, event
);
5372 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5373 if (data
->callchain
) {
5376 if (data
->callchain
)
5377 size
+= data
->callchain
->nr
;
5379 size
*= sizeof(u64
);
5381 __output_copy(handle
, data
->callchain
, size
);
5384 perf_output_put(handle
, nr
);
5388 if (sample_type
& PERF_SAMPLE_RAW
) {
5390 u32 raw_size
= data
->raw
->size
;
5391 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5392 sizeof(u64
)) - sizeof(u32
);
5395 perf_output_put(handle
, real_size
);
5396 __output_copy(handle
, data
->raw
->data
, raw_size
);
5397 if (real_size
- raw_size
)
5398 __output_copy(handle
, &zero
, real_size
- raw_size
);
5404 .size
= sizeof(u32
),
5407 perf_output_put(handle
, raw
);
5411 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5412 if (data
->br_stack
) {
5415 size
= data
->br_stack
->nr
5416 * sizeof(struct perf_branch_entry
);
5418 perf_output_put(handle
, data
->br_stack
->nr
);
5419 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5422 * we always store at least the value of nr
5425 perf_output_put(handle
, nr
);
5429 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5430 u64 abi
= data
->regs_user
.abi
;
5433 * If there are no regs to dump, notice it through
5434 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5436 perf_output_put(handle
, abi
);
5439 u64 mask
= event
->attr
.sample_regs_user
;
5440 perf_output_sample_regs(handle
,
5441 data
->regs_user
.regs
,
5446 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5447 perf_output_sample_ustack(handle
,
5448 data
->stack_user_size
,
5449 data
->regs_user
.regs
);
5452 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5453 perf_output_put(handle
, data
->weight
);
5455 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5456 perf_output_put(handle
, data
->data_src
.val
);
5458 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5459 perf_output_put(handle
, data
->txn
);
5461 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5462 u64 abi
= data
->regs_intr
.abi
;
5464 * If there are no regs to dump, notice it through
5465 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5467 perf_output_put(handle
, abi
);
5470 u64 mask
= event
->attr
.sample_regs_intr
;
5472 perf_output_sample_regs(handle
,
5473 data
->regs_intr
.regs
,
5478 if (!event
->attr
.watermark
) {
5479 int wakeup_events
= event
->attr
.wakeup_events
;
5481 if (wakeup_events
) {
5482 struct ring_buffer
*rb
= handle
->rb
;
5483 int events
= local_inc_return(&rb
->events
);
5485 if (events
>= wakeup_events
) {
5486 local_sub(wakeup_events
, &rb
->events
);
5487 local_inc(&rb
->wakeup
);
5493 void perf_prepare_sample(struct perf_event_header
*header
,
5494 struct perf_sample_data
*data
,
5495 struct perf_event
*event
,
5496 struct pt_regs
*regs
)
5498 u64 sample_type
= event
->attr
.sample_type
;
5500 header
->type
= PERF_RECORD_SAMPLE
;
5501 header
->size
= sizeof(*header
) + event
->header_size
;
5504 header
->misc
|= perf_misc_flags(regs
);
5506 __perf_event_header__init_id(header
, data
, event
);
5508 if (sample_type
& PERF_SAMPLE_IP
)
5509 data
->ip
= perf_instruction_pointer(regs
);
5511 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5514 data
->callchain
= perf_callchain(event
, regs
);
5516 if (data
->callchain
)
5517 size
+= data
->callchain
->nr
;
5519 header
->size
+= size
* sizeof(u64
);
5522 if (sample_type
& PERF_SAMPLE_RAW
) {
5523 int size
= sizeof(u32
);
5526 size
+= data
->raw
->size
;
5528 size
+= sizeof(u32
);
5530 header
->size
+= round_up(size
, sizeof(u64
));
5533 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5534 int size
= sizeof(u64
); /* nr */
5535 if (data
->br_stack
) {
5536 size
+= data
->br_stack
->nr
5537 * sizeof(struct perf_branch_entry
);
5539 header
->size
+= size
;
5542 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5543 perf_sample_regs_user(&data
->regs_user
, regs
,
5544 &data
->regs_user_copy
);
5546 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5547 /* regs dump ABI info */
5548 int size
= sizeof(u64
);
5550 if (data
->regs_user
.regs
) {
5551 u64 mask
= event
->attr
.sample_regs_user
;
5552 size
+= hweight64(mask
) * sizeof(u64
);
5555 header
->size
+= size
;
5558 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5560 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5561 * processed as the last one or have additional check added
5562 * in case new sample type is added, because we could eat
5563 * up the rest of the sample size.
5565 u16 stack_size
= event
->attr
.sample_stack_user
;
5566 u16 size
= sizeof(u64
);
5568 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5569 data
->regs_user
.regs
);
5572 * If there is something to dump, add space for the dump
5573 * itself and for the field that tells the dynamic size,
5574 * which is how many have been actually dumped.
5577 size
+= sizeof(u64
) + stack_size
;
5579 data
->stack_user_size
= stack_size
;
5580 header
->size
+= size
;
5583 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5584 /* regs dump ABI info */
5585 int size
= sizeof(u64
);
5587 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5589 if (data
->regs_intr
.regs
) {
5590 u64 mask
= event
->attr
.sample_regs_intr
;
5592 size
+= hweight64(mask
) * sizeof(u64
);
5595 header
->size
+= size
;
5599 void perf_event_output(struct perf_event
*event
,
5600 struct perf_sample_data
*data
,
5601 struct pt_regs
*regs
)
5603 struct perf_output_handle handle
;
5604 struct perf_event_header header
;
5606 /* protect the callchain buffers */
5609 perf_prepare_sample(&header
, data
, event
, regs
);
5611 if (perf_output_begin(&handle
, event
, header
.size
))
5614 perf_output_sample(&handle
, &header
, data
, event
);
5616 perf_output_end(&handle
);
5626 struct perf_read_event
{
5627 struct perf_event_header header
;
5634 perf_event_read_event(struct perf_event
*event
,
5635 struct task_struct
*task
)
5637 struct perf_output_handle handle
;
5638 struct perf_sample_data sample
;
5639 struct perf_read_event read_event
= {
5641 .type
= PERF_RECORD_READ
,
5643 .size
= sizeof(read_event
) + event
->read_size
,
5645 .pid
= perf_event_pid(event
, task
),
5646 .tid
= perf_event_tid(event
, task
),
5650 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5651 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5655 perf_output_put(&handle
, read_event
);
5656 perf_output_read(&handle
, event
);
5657 perf_event__output_id_sample(event
, &handle
, &sample
);
5659 perf_output_end(&handle
);
5662 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5665 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5666 perf_event_aux_output_cb output
,
5669 struct perf_event
*event
;
5671 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5672 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5674 if (!event_filter_match(event
))
5676 output(event
, data
);
5681 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5682 struct perf_event_context
*task_ctx
)
5686 perf_event_aux_ctx(task_ctx
, output
, data
);
5692 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5693 struct perf_event_context
*task_ctx
)
5695 struct perf_cpu_context
*cpuctx
;
5696 struct perf_event_context
*ctx
;
5701 * If we have task_ctx != NULL we only notify
5702 * the task context itself. The task_ctx is set
5703 * only for EXIT events before releasing task
5707 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5712 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5713 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5714 if (cpuctx
->unique_pmu
!= pmu
)
5716 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5717 ctxn
= pmu
->task_ctx_nr
;
5720 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5722 perf_event_aux_ctx(ctx
, output
, data
);
5724 put_cpu_ptr(pmu
->pmu_cpu_context
);
5730 * task tracking -- fork/exit
5732 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5735 struct perf_task_event
{
5736 struct task_struct
*task
;
5737 struct perf_event_context
*task_ctx
;
5740 struct perf_event_header header
;
5750 static int perf_event_task_match(struct perf_event
*event
)
5752 return event
->attr
.comm
|| event
->attr
.mmap
||
5753 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5757 static void perf_event_task_output(struct perf_event
*event
,
5760 struct perf_task_event
*task_event
= data
;
5761 struct perf_output_handle handle
;
5762 struct perf_sample_data sample
;
5763 struct task_struct
*task
= task_event
->task
;
5764 int ret
, size
= task_event
->event_id
.header
.size
;
5766 if (!perf_event_task_match(event
))
5769 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5771 ret
= perf_output_begin(&handle
, event
,
5772 task_event
->event_id
.header
.size
);
5776 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5777 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5779 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5780 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5782 task_event
->event_id
.time
= perf_event_clock(event
);
5784 perf_output_put(&handle
, task_event
->event_id
);
5786 perf_event__output_id_sample(event
, &handle
, &sample
);
5788 perf_output_end(&handle
);
5790 task_event
->event_id
.header
.size
= size
;
5793 static void perf_event_task(struct task_struct
*task
,
5794 struct perf_event_context
*task_ctx
,
5797 struct perf_task_event task_event
;
5799 if (!atomic_read(&nr_comm_events
) &&
5800 !atomic_read(&nr_mmap_events
) &&
5801 !atomic_read(&nr_task_events
))
5804 task_event
= (struct perf_task_event
){
5806 .task_ctx
= task_ctx
,
5809 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5811 .size
= sizeof(task_event
.event_id
),
5821 perf_event_aux(perf_event_task_output
,
5826 void perf_event_fork(struct task_struct
*task
)
5828 perf_event_task(task
, NULL
, 1);
5835 struct perf_comm_event
{
5836 struct task_struct
*task
;
5841 struct perf_event_header header
;
5848 static int perf_event_comm_match(struct perf_event
*event
)
5850 return event
->attr
.comm
;
5853 static void perf_event_comm_output(struct perf_event
*event
,
5856 struct perf_comm_event
*comm_event
= data
;
5857 struct perf_output_handle handle
;
5858 struct perf_sample_data sample
;
5859 int size
= comm_event
->event_id
.header
.size
;
5862 if (!perf_event_comm_match(event
))
5865 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5866 ret
= perf_output_begin(&handle
, event
,
5867 comm_event
->event_id
.header
.size
);
5872 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5873 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5875 perf_output_put(&handle
, comm_event
->event_id
);
5876 __output_copy(&handle
, comm_event
->comm
,
5877 comm_event
->comm_size
);
5879 perf_event__output_id_sample(event
, &handle
, &sample
);
5881 perf_output_end(&handle
);
5883 comm_event
->event_id
.header
.size
= size
;
5886 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5888 char comm
[TASK_COMM_LEN
];
5891 memset(comm
, 0, sizeof(comm
));
5892 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5893 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5895 comm_event
->comm
= comm
;
5896 comm_event
->comm_size
= size
;
5898 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5900 perf_event_aux(perf_event_comm_output
,
5905 void perf_event_comm(struct task_struct
*task
, bool exec
)
5907 struct perf_comm_event comm_event
;
5909 if (!atomic_read(&nr_comm_events
))
5912 comm_event
= (struct perf_comm_event
){
5918 .type
= PERF_RECORD_COMM
,
5919 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5927 perf_event_comm_event(&comm_event
);
5934 struct perf_mmap_event
{
5935 struct vm_area_struct
*vma
;
5937 const char *file_name
;
5945 struct perf_event_header header
;
5955 static int perf_event_mmap_match(struct perf_event
*event
,
5958 struct perf_mmap_event
*mmap_event
= data
;
5959 struct vm_area_struct
*vma
= mmap_event
->vma
;
5960 int executable
= vma
->vm_flags
& VM_EXEC
;
5962 return (!executable
&& event
->attr
.mmap_data
) ||
5963 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5966 static void perf_event_mmap_output(struct perf_event
*event
,
5969 struct perf_mmap_event
*mmap_event
= data
;
5970 struct perf_output_handle handle
;
5971 struct perf_sample_data sample
;
5972 int size
= mmap_event
->event_id
.header
.size
;
5975 if (!perf_event_mmap_match(event
, data
))
5978 if (event
->attr
.mmap2
) {
5979 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5980 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5981 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5982 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5983 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5984 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5985 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5988 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5989 ret
= perf_output_begin(&handle
, event
,
5990 mmap_event
->event_id
.header
.size
);
5994 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5995 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5997 perf_output_put(&handle
, mmap_event
->event_id
);
5999 if (event
->attr
.mmap2
) {
6000 perf_output_put(&handle
, mmap_event
->maj
);
6001 perf_output_put(&handle
, mmap_event
->min
);
6002 perf_output_put(&handle
, mmap_event
->ino
);
6003 perf_output_put(&handle
, mmap_event
->ino_generation
);
6004 perf_output_put(&handle
, mmap_event
->prot
);
6005 perf_output_put(&handle
, mmap_event
->flags
);
6008 __output_copy(&handle
, mmap_event
->file_name
,
6009 mmap_event
->file_size
);
6011 perf_event__output_id_sample(event
, &handle
, &sample
);
6013 perf_output_end(&handle
);
6015 mmap_event
->event_id
.header
.size
= size
;
6018 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6020 struct vm_area_struct
*vma
= mmap_event
->vma
;
6021 struct file
*file
= vma
->vm_file
;
6022 int maj
= 0, min
= 0;
6023 u64 ino
= 0, gen
= 0;
6024 u32 prot
= 0, flags
= 0;
6031 struct inode
*inode
;
6034 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6040 * d_path() works from the end of the rb backwards, so we
6041 * need to add enough zero bytes after the string to handle
6042 * the 64bit alignment we do later.
6044 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6049 inode
= file_inode(vma
->vm_file
);
6050 dev
= inode
->i_sb
->s_dev
;
6052 gen
= inode
->i_generation
;
6056 if (vma
->vm_flags
& VM_READ
)
6058 if (vma
->vm_flags
& VM_WRITE
)
6060 if (vma
->vm_flags
& VM_EXEC
)
6063 if (vma
->vm_flags
& VM_MAYSHARE
)
6066 flags
= MAP_PRIVATE
;
6068 if (vma
->vm_flags
& VM_DENYWRITE
)
6069 flags
|= MAP_DENYWRITE
;
6070 if (vma
->vm_flags
& VM_MAYEXEC
)
6071 flags
|= MAP_EXECUTABLE
;
6072 if (vma
->vm_flags
& VM_LOCKED
)
6073 flags
|= MAP_LOCKED
;
6074 if (vma
->vm_flags
& VM_HUGETLB
)
6075 flags
|= MAP_HUGETLB
;
6079 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6080 name
= (char *) vma
->vm_ops
->name(vma
);
6085 name
= (char *)arch_vma_name(vma
);
6089 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6090 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6094 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6095 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6105 strlcpy(tmp
, name
, sizeof(tmp
));
6109 * Since our buffer works in 8 byte units we need to align our string
6110 * size to a multiple of 8. However, we must guarantee the tail end is
6111 * zero'd out to avoid leaking random bits to userspace.
6113 size
= strlen(name
)+1;
6114 while (!IS_ALIGNED(size
, sizeof(u64
)))
6115 name
[size
++] = '\0';
6117 mmap_event
->file_name
= name
;
6118 mmap_event
->file_size
= size
;
6119 mmap_event
->maj
= maj
;
6120 mmap_event
->min
= min
;
6121 mmap_event
->ino
= ino
;
6122 mmap_event
->ino_generation
= gen
;
6123 mmap_event
->prot
= prot
;
6124 mmap_event
->flags
= flags
;
6126 if (!(vma
->vm_flags
& VM_EXEC
))
6127 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6129 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6131 perf_event_aux(perf_event_mmap_output
,
6138 void perf_event_mmap(struct vm_area_struct
*vma
)
6140 struct perf_mmap_event mmap_event
;
6142 if (!atomic_read(&nr_mmap_events
))
6145 mmap_event
= (struct perf_mmap_event
){
6151 .type
= PERF_RECORD_MMAP
,
6152 .misc
= PERF_RECORD_MISC_USER
,
6157 .start
= vma
->vm_start
,
6158 .len
= vma
->vm_end
- vma
->vm_start
,
6159 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6161 /* .maj (attr_mmap2 only) */
6162 /* .min (attr_mmap2 only) */
6163 /* .ino (attr_mmap2 only) */
6164 /* .ino_generation (attr_mmap2 only) */
6165 /* .prot (attr_mmap2 only) */
6166 /* .flags (attr_mmap2 only) */
6169 perf_event_mmap_event(&mmap_event
);
6172 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6173 unsigned long size
, u64 flags
)
6175 struct perf_output_handle handle
;
6176 struct perf_sample_data sample
;
6177 struct perf_aux_event
{
6178 struct perf_event_header header
;
6184 .type
= PERF_RECORD_AUX
,
6186 .size
= sizeof(rec
),
6194 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6195 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6200 perf_output_put(&handle
, rec
);
6201 perf_event__output_id_sample(event
, &handle
, &sample
);
6203 perf_output_end(&handle
);
6207 * Lost/dropped samples logging
6209 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6211 struct perf_output_handle handle
;
6212 struct perf_sample_data sample
;
6216 struct perf_event_header header
;
6218 } lost_samples_event
= {
6220 .type
= PERF_RECORD_LOST_SAMPLES
,
6222 .size
= sizeof(lost_samples_event
),
6227 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6229 ret
= perf_output_begin(&handle
, event
,
6230 lost_samples_event
.header
.size
);
6234 perf_output_put(&handle
, lost_samples_event
);
6235 perf_event__output_id_sample(event
, &handle
, &sample
);
6236 perf_output_end(&handle
);
6240 * context_switch tracking
6243 struct perf_switch_event
{
6244 struct task_struct
*task
;
6245 struct task_struct
*next_prev
;
6248 struct perf_event_header header
;
6254 static int perf_event_switch_match(struct perf_event
*event
)
6256 return event
->attr
.context_switch
;
6259 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6261 struct perf_switch_event
*se
= data
;
6262 struct perf_output_handle handle
;
6263 struct perf_sample_data sample
;
6266 if (!perf_event_switch_match(event
))
6269 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6270 if (event
->ctx
->task
) {
6271 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6272 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6274 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6275 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6276 se
->event_id
.next_prev_pid
=
6277 perf_event_pid(event
, se
->next_prev
);
6278 se
->event_id
.next_prev_tid
=
6279 perf_event_tid(event
, se
->next_prev
);
6282 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6284 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6288 if (event
->ctx
->task
)
6289 perf_output_put(&handle
, se
->event_id
.header
);
6291 perf_output_put(&handle
, se
->event_id
);
6293 perf_event__output_id_sample(event
, &handle
, &sample
);
6295 perf_output_end(&handle
);
6298 static void perf_event_switch(struct task_struct
*task
,
6299 struct task_struct
*next_prev
, bool sched_in
)
6301 struct perf_switch_event switch_event
;
6303 /* N.B. caller checks nr_switch_events != 0 */
6305 switch_event
= (struct perf_switch_event
){
6307 .next_prev
= next_prev
,
6311 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6314 /* .next_prev_pid */
6315 /* .next_prev_tid */
6319 perf_event_aux(perf_event_switch_output
,
6325 * IRQ throttle logging
6328 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6330 struct perf_output_handle handle
;
6331 struct perf_sample_data sample
;
6335 struct perf_event_header header
;
6339 } throttle_event
= {
6341 .type
= PERF_RECORD_THROTTLE
,
6343 .size
= sizeof(throttle_event
),
6345 .time
= perf_event_clock(event
),
6346 .id
= primary_event_id(event
),
6347 .stream_id
= event
->id
,
6351 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6353 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6355 ret
= perf_output_begin(&handle
, event
,
6356 throttle_event
.header
.size
);
6360 perf_output_put(&handle
, throttle_event
);
6361 perf_event__output_id_sample(event
, &handle
, &sample
);
6362 perf_output_end(&handle
);
6365 static void perf_log_itrace_start(struct perf_event
*event
)
6367 struct perf_output_handle handle
;
6368 struct perf_sample_data sample
;
6369 struct perf_aux_event
{
6370 struct perf_event_header header
;
6377 event
= event
->parent
;
6379 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6380 event
->hw
.itrace_started
)
6383 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6384 rec
.header
.misc
= 0;
6385 rec
.header
.size
= sizeof(rec
);
6386 rec
.pid
= perf_event_pid(event
, current
);
6387 rec
.tid
= perf_event_tid(event
, current
);
6389 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6390 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6395 perf_output_put(&handle
, rec
);
6396 perf_event__output_id_sample(event
, &handle
, &sample
);
6398 perf_output_end(&handle
);
6402 * Generic event overflow handling, sampling.
6405 static int __perf_event_overflow(struct perf_event
*event
,
6406 int throttle
, struct perf_sample_data
*data
,
6407 struct pt_regs
*regs
)
6409 int events
= atomic_read(&event
->event_limit
);
6410 struct hw_perf_event
*hwc
= &event
->hw
;
6415 * Non-sampling counters might still use the PMI to fold short
6416 * hardware counters, ignore those.
6418 if (unlikely(!is_sampling_event(event
)))
6421 seq
= __this_cpu_read(perf_throttled_seq
);
6422 if (seq
!= hwc
->interrupts_seq
) {
6423 hwc
->interrupts_seq
= seq
;
6424 hwc
->interrupts
= 1;
6427 if (unlikely(throttle
6428 && hwc
->interrupts
>= max_samples_per_tick
)) {
6429 __this_cpu_inc(perf_throttled_count
);
6430 hwc
->interrupts
= MAX_INTERRUPTS
;
6431 perf_log_throttle(event
, 0);
6432 tick_nohz_full_kick();
6437 if (event
->attr
.freq
) {
6438 u64 now
= perf_clock();
6439 s64 delta
= now
- hwc
->freq_time_stamp
;
6441 hwc
->freq_time_stamp
= now
;
6443 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6444 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6448 * XXX event_limit might not quite work as expected on inherited
6452 event
->pending_kill
= POLL_IN
;
6453 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6455 event
->pending_kill
= POLL_HUP
;
6456 event
->pending_disable
= 1;
6457 irq_work_queue(&event
->pending
);
6460 if (event
->overflow_handler
)
6461 event
->overflow_handler(event
, data
, regs
);
6463 perf_event_output(event
, data
, regs
);
6465 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6466 event
->pending_wakeup
= 1;
6467 irq_work_queue(&event
->pending
);
6473 int perf_event_overflow(struct perf_event
*event
,
6474 struct perf_sample_data
*data
,
6475 struct pt_regs
*regs
)
6477 return __perf_event_overflow(event
, 1, data
, regs
);
6481 * Generic software event infrastructure
6484 struct swevent_htable
{
6485 struct swevent_hlist
*swevent_hlist
;
6486 struct mutex hlist_mutex
;
6489 /* Recursion avoidance in each contexts */
6490 int recursion
[PERF_NR_CONTEXTS
];
6493 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6496 * We directly increment event->count and keep a second value in
6497 * event->hw.period_left to count intervals. This period event
6498 * is kept in the range [-sample_period, 0] so that we can use the
6502 u64
perf_swevent_set_period(struct perf_event
*event
)
6504 struct hw_perf_event
*hwc
= &event
->hw
;
6505 u64 period
= hwc
->last_period
;
6509 hwc
->last_period
= hwc
->sample_period
;
6512 old
= val
= local64_read(&hwc
->period_left
);
6516 nr
= div64_u64(period
+ val
, period
);
6517 offset
= nr
* period
;
6519 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6525 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6526 struct perf_sample_data
*data
,
6527 struct pt_regs
*regs
)
6529 struct hw_perf_event
*hwc
= &event
->hw
;
6533 overflow
= perf_swevent_set_period(event
);
6535 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6538 for (; overflow
; overflow
--) {
6539 if (__perf_event_overflow(event
, throttle
,
6542 * We inhibit the overflow from happening when
6543 * hwc->interrupts == MAX_INTERRUPTS.
6551 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6552 struct perf_sample_data
*data
,
6553 struct pt_regs
*regs
)
6555 struct hw_perf_event
*hwc
= &event
->hw
;
6557 local64_add(nr
, &event
->count
);
6562 if (!is_sampling_event(event
))
6565 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6567 return perf_swevent_overflow(event
, 1, data
, regs
);
6569 data
->period
= event
->hw
.last_period
;
6571 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6572 return perf_swevent_overflow(event
, 1, data
, regs
);
6574 if (local64_add_negative(nr
, &hwc
->period_left
))
6577 perf_swevent_overflow(event
, 0, data
, regs
);
6580 static int perf_exclude_event(struct perf_event
*event
,
6581 struct pt_regs
*regs
)
6583 if (event
->hw
.state
& PERF_HES_STOPPED
)
6587 if (event
->attr
.exclude_user
&& user_mode(regs
))
6590 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6597 static int perf_swevent_match(struct perf_event
*event
,
6598 enum perf_type_id type
,
6600 struct perf_sample_data
*data
,
6601 struct pt_regs
*regs
)
6603 if (event
->attr
.type
!= type
)
6606 if (event
->attr
.config
!= event_id
)
6609 if (perf_exclude_event(event
, regs
))
6615 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6617 u64 val
= event_id
| (type
<< 32);
6619 return hash_64(val
, SWEVENT_HLIST_BITS
);
6622 static inline struct hlist_head
*
6623 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6625 u64 hash
= swevent_hash(type
, event_id
);
6627 return &hlist
->heads
[hash
];
6630 /* For the read side: events when they trigger */
6631 static inline struct hlist_head
*
6632 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6634 struct swevent_hlist
*hlist
;
6636 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6640 return __find_swevent_head(hlist
, type
, event_id
);
6643 /* For the event head insertion and removal in the hlist */
6644 static inline struct hlist_head
*
6645 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6647 struct swevent_hlist
*hlist
;
6648 u32 event_id
= event
->attr
.config
;
6649 u64 type
= event
->attr
.type
;
6652 * Event scheduling is always serialized against hlist allocation
6653 * and release. Which makes the protected version suitable here.
6654 * The context lock guarantees that.
6656 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6657 lockdep_is_held(&event
->ctx
->lock
));
6661 return __find_swevent_head(hlist
, type
, event_id
);
6664 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6666 struct perf_sample_data
*data
,
6667 struct pt_regs
*regs
)
6669 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6670 struct perf_event
*event
;
6671 struct hlist_head
*head
;
6674 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6678 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6679 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6680 perf_swevent_event(event
, nr
, data
, regs
);
6686 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6688 int perf_swevent_get_recursion_context(void)
6690 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6692 return get_recursion_context(swhash
->recursion
);
6694 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6696 inline void perf_swevent_put_recursion_context(int rctx
)
6698 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6700 put_recursion_context(swhash
->recursion
, rctx
);
6703 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6705 struct perf_sample_data data
;
6707 if (WARN_ON_ONCE(!regs
))
6710 perf_sample_data_init(&data
, addr
, 0);
6711 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6714 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6718 preempt_disable_notrace();
6719 rctx
= perf_swevent_get_recursion_context();
6720 if (unlikely(rctx
< 0))
6723 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6725 perf_swevent_put_recursion_context(rctx
);
6727 preempt_enable_notrace();
6730 static void perf_swevent_read(struct perf_event
*event
)
6734 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6736 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6737 struct hw_perf_event
*hwc
= &event
->hw
;
6738 struct hlist_head
*head
;
6740 if (is_sampling_event(event
)) {
6741 hwc
->last_period
= hwc
->sample_period
;
6742 perf_swevent_set_period(event
);
6745 hwc
->state
= !(flags
& PERF_EF_START
);
6747 head
= find_swevent_head(swhash
, event
);
6748 if (WARN_ON_ONCE(!head
))
6751 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6752 perf_event_update_userpage(event
);
6757 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6759 hlist_del_rcu(&event
->hlist_entry
);
6762 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6764 event
->hw
.state
= 0;
6767 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6769 event
->hw
.state
= PERF_HES_STOPPED
;
6772 /* Deref the hlist from the update side */
6773 static inline struct swevent_hlist
*
6774 swevent_hlist_deref(struct swevent_htable
*swhash
)
6776 return rcu_dereference_protected(swhash
->swevent_hlist
,
6777 lockdep_is_held(&swhash
->hlist_mutex
));
6780 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6782 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6787 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6788 kfree_rcu(hlist
, rcu_head
);
6791 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6793 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6795 mutex_lock(&swhash
->hlist_mutex
);
6797 if (!--swhash
->hlist_refcount
)
6798 swevent_hlist_release(swhash
);
6800 mutex_unlock(&swhash
->hlist_mutex
);
6803 static void swevent_hlist_put(struct perf_event
*event
)
6807 for_each_possible_cpu(cpu
)
6808 swevent_hlist_put_cpu(event
, cpu
);
6811 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6813 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6816 mutex_lock(&swhash
->hlist_mutex
);
6817 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6818 struct swevent_hlist
*hlist
;
6820 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6825 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6827 swhash
->hlist_refcount
++;
6829 mutex_unlock(&swhash
->hlist_mutex
);
6834 static int swevent_hlist_get(struct perf_event
*event
)
6837 int cpu
, failed_cpu
;
6840 for_each_possible_cpu(cpu
) {
6841 err
= swevent_hlist_get_cpu(event
, cpu
);
6851 for_each_possible_cpu(cpu
) {
6852 if (cpu
== failed_cpu
)
6854 swevent_hlist_put_cpu(event
, cpu
);
6861 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6863 static void sw_perf_event_destroy(struct perf_event
*event
)
6865 u64 event_id
= event
->attr
.config
;
6867 WARN_ON(event
->parent
);
6869 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6870 swevent_hlist_put(event
);
6873 static int perf_swevent_init(struct perf_event
*event
)
6875 u64 event_id
= event
->attr
.config
;
6877 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6881 * no branch sampling for software events
6883 if (has_branch_stack(event
))
6887 case PERF_COUNT_SW_CPU_CLOCK
:
6888 case PERF_COUNT_SW_TASK_CLOCK
:
6895 if (event_id
>= PERF_COUNT_SW_MAX
)
6898 if (!event
->parent
) {
6901 err
= swevent_hlist_get(event
);
6905 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6906 event
->destroy
= sw_perf_event_destroy
;
6912 static struct pmu perf_swevent
= {
6913 .task_ctx_nr
= perf_sw_context
,
6915 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6917 .event_init
= perf_swevent_init
,
6918 .add
= perf_swevent_add
,
6919 .del
= perf_swevent_del
,
6920 .start
= perf_swevent_start
,
6921 .stop
= perf_swevent_stop
,
6922 .read
= perf_swevent_read
,
6925 #ifdef CONFIG_EVENT_TRACING
6927 static int perf_tp_filter_match(struct perf_event
*event
,
6928 struct perf_sample_data
*data
)
6930 void *record
= data
->raw
->data
;
6932 /* only top level events have filters set */
6934 event
= event
->parent
;
6936 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6941 static int perf_tp_event_match(struct perf_event
*event
,
6942 struct perf_sample_data
*data
,
6943 struct pt_regs
*regs
)
6945 if (event
->hw
.state
& PERF_HES_STOPPED
)
6948 * All tracepoints are from kernel-space.
6950 if (event
->attr
.exclude_kernel
)
6953 if (!perf_tp_filter_match(event
, data
))
6959 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6960 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6961 struct task_struct
*task
)
6963 struct perf_sample_data data
;
6964 struct perf_event
*event
;
6966 struct perf_raw_record raw
= {
6971 perf_sample_data_init(&data
, addr
, 0);
6974 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6975 if (perf_tp_event_match(event
, &data
, regs
))
6976 perf_swevent_event(event
, count
, &data
, regs
);
6980 * If we got specified a target task, also iterate its context and
6981 * deliver this event there too.
6983 if (task
&& task
!= current
) {
6984 struct perf_event_context
*ctx
;
6985 struct trace_entry
*entry
= record
;
6988 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6992 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6993 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6995 if (event
->attr
.config
!= entry
->type
)
6997 if (perf_tp_event_match(event
, &data
, regs
))
6998 perf_swevent_event(event
, count
, &data
, regs
);
7004 perf_swevent_put_recursion_context(rctx
);
7006 EXPORT_SYMBOL_GPL(perf_tp_event
);
7008 static void tp_perf_event_destroy(struct perf_event
*event
)
7010 perf_trace_destroy(event
);
7013 static int perf_tp_event_init(struct perf_event
*event
)
7017 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7021 * no branch sampling for tracepoint events
7023 if (has_branch_stack(event
))
7026 err
= perf_trace_init(event
);
7030 event
->destroy
= tp_perf_event_destroy
;
7035 static struct pmu perf_tracepoint
= {
7036 .task_ctx_nr
= perf_sw_context
,
7038 .event_init
= perf_tp_event_init
,
7039 .add
= perf_trace_add
,
7040 .del
= perf_trace_del
,
7041 .start
= perf_swevent_start
,
7042 .stop
= perf_swevent_stop
,
7043 .read
= perf_swevent_read
,
7046 static inline void perf_tp_register(void)
7048 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7051 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7056 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7059 filter_str
= strndup_user(arg
, PAGE_SIZE
);
7060 if (IS_ERR(filter_str
))
7061 return PTR_ERR(filter_str
);
7063 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7069 static void perf_event_free_filter(struct perf_event
*event
)
7071 ftrace_profile_free_filter(event
);
7074 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7076 struct bpf_prog
*prog
;
7078 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7081 if (event
->tp_event
->prog
)
7084 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7085 /* bpf programs can only be attached to u/kprobes */
7088 prog
= bpf_prog_get(prog_fd
);
7090 return PTR_ERR(prog
);
7092 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7093 /* valid fd, but invalid bpf program type */
7098 event
->tp_event
->prog
= prog
;
7103 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7105 struct bpf_prog
*prog
;
7107 if (!event
->tp_event
)
7110 prog
= event
->tp_event
->prog
;
7112 event
->tp_event
->prog
= NULL
;
7119 static inline void perf_tp_register(void)
7123 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7128 static void perf_event_free_filter(struct perf_event
*event
)
7132 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7137 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7140 #endif /* CONFIG_EVENT_TRACING */
7142 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7143 void perf_bp_event(struct perf_event
*bp
, void *data
)
7145 struct perf_sample_data sample
;
7146 struct pt_regs
*regs
= data
;
7148 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7150 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7151 perf_swevent_event(bp
, 1, &sample
, regs
);
7156 * hrtimer based swevent callback
7159 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7161 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7162 struct perf_sample_data data
;
7163 struct pt_regs
*regs
;
7164 struct perf_event
*event
;
7167 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7169 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7170 return HRTIMER_NORESTART
;
7172 event
->pmu
->read(event
);
7174 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7175 regs
= get_irq_regs();
7177 if (regs
&& !perf_exclude_event(event
, regs
)) {
7178 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7179 if (__perf_event_overflow(event
, 1, &data
, regs
))
7180 ret
= HRTIMER_NORESTART
;
7183 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7184 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7189 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7191 struct hw_perf_event
*hwc
= &event
->hw
;
7194 if (!is_sampling_event(event
))
7197 period
= local64_read(&hwc
->period_left
);
7202 local64_set(&hwc
->period_left
, 0);
7204 period
= max_t(u64
, 10000, hwc
->sample_period
);
7206 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7207 HRTIMER_MODE_REL_PINNED
);
7210 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7212 struct hw_perf_event
*hwc
= &event
->hw
;
7214 if (is_sampling_event(event
)) {
7215 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7216 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7218 hrtimer_cancel(&hwc
->hrtimer
);
7222 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7224 struct hw_perf_event
*hwc
= &event
->hw
;
7226 if (!is_sampling_event(event
))
7229 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7230 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7233 * Since hrtimers have a fixed rate, we can do a static freq->period
7234 * mapping and avoid the whole period adjust feedback stuff.
7236 if (event
->attr
.freq
) {
7237 long freq
= event
->attr
.sample_freq
;
7239 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7240 hwc
->sample_period
= event
->attr
.sample_period
;
7241 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7242 hwc
->last_period
= hwc
->sample_period
;
7243 event
->attr
.freq
= 0;
7248 * Software event: cpu wall time clock
7251 static void cpu_clock_event_update(struct perf_event
*event
)
7256 now
= local_clock();
7257 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7258 local64_add(now
- prev
, &event
->count
);
7261 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7263 local64_set(&event
->hw
.prev_count
, local_clock());
7264 perf_swevent_start_hrtimer(event
);
7267 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7269 perf_swevent_cancel_hrtimer(event
);
7270 cpu_clock_event_update(event
);
7273 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7275 if (flags
& PERF_EF_START
)
7276 cpu_clock_event_start(event
, flags
);
7277 perf_event_update_userpage(event
);
7282 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7284 cpu_clock_event_stop(event
, flags
);
7287 static void cpu_clock_event_read(struct perf_event
*event
)
7289 cpu_clock_event_update(event
);
7292 static int cpu_clock_event_init(struct perf_event
*event
)
7294 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7297 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7301 * no branch sampling for software events
7303 if (has_branch_stack(event
))
7306 perf_swevent_init_hrtimer(event
);
7311 static struct pmu perf_cpu_clock
= {
7312 .task_ctx_nr
= perf_sw_context
,
7314 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7316 .event_init
= cpu_clock_event_init
,
7317 .add
= cpu_clock_event_add
,
7318 .del
= cpu_clock_event_del
,
7319 .start
= cpu_clock_event_start
,
7320 .stop
= cpu_clock_event_stop
,
7321 .read
= cpu_clock_event_read
,
7325 * Software event: task time clock
7328 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7333 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7335 local64_add(delta
, &event
->count
);
7338 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7340 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7341 perf_swevent_start_hrtimer(event
);
7344 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7346 perf_swevent_cancel_hrtimer(event
);
7347 task_clock_event_update(event
, event
->ctx
->time
);
7350 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7352 if (flags
& PERF_EF_START
)
7353 task_clock_event_start(event
, flags
);
7354 perf_event_update_userpage(event
);
7359 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7361 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7364 static void task_clock_event_read(struct perf_event
*event
)
7366 u64 now
= perf_clock();
7367 u64 delta
= now
- event
->ctx
->timestamp
;
7368 u64 time
= event
->ctx
->time
+ delta
;
7370 task_clock_event_update(event
, time
);
7373 static int task_clock_event_init(struct perf_event
*event
)
7375 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7378 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7382 * no branch sampling for software events
7384 if (has_branch_stack(event
))
7387 perf_swevent_init_hrtimer(event
);
7392 static struct pmu perf_task_clock
= {
7393 .task_ctx_nr
= perf_sw_context
,
7395 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7397 .event_init
= task_clock_event_init
,
7398 .add
= task_clock_event_add
,
7399 .del
= task_clock_event_del
,
7400 .start
= task_clock_event_start
,
7401 .stop
= task_clock_event_stop
,
7402 .read
= task_clock_event_read
,
7405 static void perf_pmu_nop_void(struct pmu
*pmu
)
7409 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7413 static int perf_pmu_nop_int(struct pmu
*pmu
)
7418 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7420 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7422 __this_cpu_write(nop_txn_flags
, flags
);
7424 if (flags
& ~PERF_PMU_TXN_ADD
)
7427 perf_pmu_disable(pmu
);
7430 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7432 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7434 __this_cpu_write(nop_txn_flags
, 0);
7436 if (flags
& ~PERF_PMU_TXN_ADD
)
7439 perf_pmu_enable(pmu
);
7443 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7445 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7447 __this_cpu_write(nop_txn_flags
, 0);
7449 if (flags
& ~PERF_PMU_TXN_ADD
)
7452 perf_pmu_enable(pmu
);
7455 static int perf_event_idx_default(struct perf_event
*event
)
7461 * Ensures all contexts with the same task_ctx_nr have the same
7462 * pmu_cpu_context too.
7464 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7471 list_for_each_entry(pmu
, &pmus
, entry
) {
7472 if (pmu
->task_ctx_nr
== ctxn
)
7473 return pmu
->pmu_cpu_context
;
7479 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7483 for_each_possible_cpu(cpu
) {
7484 struct perf_cpu_context
*cpuctx
;
7486 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7488 if (cpuctx
->unique_pmu
== old_pmu
)
7489 cpuctx
->unique_pmu
= pmu
;
7493 static void free_pmu_context(struct pmu
*pmu
)
7497 mutex_lock(&pmus_lock
);
7499 * Like a real lame refcount.
7501 list_for_each_entry(i
, &pmus
, entry
) {
7502 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7503 update_pmu_context(i
, pmu
);
7508 free_percpu(pmu
->pmu_cpu_context
);
7510 mutex_unlock(&pmus_lock
);
7512 static struct idr pmu_idr
;
7515 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7517 struct pmu
*pmu
= dev_get_drvdata(dev
);
7519 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7521 static DEVICE_ATTR_RO(type
);
7524 perf_event_mux_interval_ms_show(struct device
*dev
,
7525 struct device_attribute
*attr
,
7528 struct pmu
*pmu
= dev_get_drvdata(dev
);
7530 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7533 static DEFINE_MUTEX(mux_interval_mutex
);
7536 perf_event_mux_interval_ms_store(struct device
*dev
,
7537 struct device_attribute
*attr
,
7538 const char *buf
, size_t count
)
7540 struct pmu
*pmu
= dev_get_drvdata(dev
);
7541 int timer
, cpu
, ret
;
7543 ret
= kstrtoint(buf
, 0, &timer
);
7550 /* same value, noting to do */
7551 if (timer
== pmu
->hrtimer_interval_ms
)
7554 mutex_lock(&mux_interval_mutex
);
7555 pmu
->hrtimer_interval_ms
= timer
;
7557 /* update all cpuctx for this PMU */
7559 for_each_online_cpu(cpu
) {
7560 struct perf_cpu_context
*cpuctx
;
7561 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7562 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7564 cpu_function_call(cpu
,
7565 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7568 mutex_unlock(&mux_interval_mutex
);
7572 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7574 static struct attribute
*pmu_dev_attrs
[] = {
7575 &dev_attr_type
.attr
,
7576 &dev_attr_perf_event_mux_interval_ms
.attr
,
7579 ATTRIBUTE_GROUPS(pmu_dev
);
7581 static int pmu_bus_running
;
7582 static struct bus_type pmu_bus
= {
7583 .name
= "event_source",
7584 .dev_groups
= pmu_dev_groups
,
7587 static void pmu_dev_release(struct device
*dev
)
7592 static int pmu_dev_alloc(struct pmu
*pmu
)
7596 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7600 pmu
->dev
->groups
= pmu
->attr_groups
;
7601 device_initialize(pmu
->dev
);
7602 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7606 dev_set_drvdata(pmu
->dev
, pmu
);
7607 pmu
->dev
->bus
= &pmu_bus
;
7608 pmu
->dev
->release
= pmu_dev_release
;
7609 ret
= device_add(pmu
->dev
);
7617 put_device(pmu
->dev
);
7621 static struct lock_class_key cpuctx_mutex
;
7622 static struct lock_class_key cpuctx_lock
;
7624 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7628 mutex_lock(&pmus_lock
);
7630 pmu
->pmu_disable_count
= alloc_percpu(int);
7631 if (!pmu
->pmu_disable_count
)
7640 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7648 if (pmu_bus_running
) {
7649 ret
= pmu_dev_alloc(pmu
);
7655 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7656 if (pmu
->pmu_cpu_context
)
7657 goto got_cpu_context
;
7660 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7661 if (!pmu
->pmu_cpu_context
)
7664 for_each_possible_cpu(cpu
) {
7665 struct perf_cpu_context
*cpuctx
;
7667 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7668 __perf_event_init_context(&cpuctx
->ctx
);
7669 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7670 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7671 cpuctx
->ctx
.pmu
= pmu
;
7673 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7675 cpuctx
->unique_pmu
= pmu
;
7679 if (!pmu
->start_txn
) {
7680 if (pmu
->pmu_enable
) {
7682 * If we have pmu_enable/pmu_disable calls, install
7683 * transaction stubs that use that to try and batch
7684 * hardware accesses.
7686 pmu
->start_txn
= perf_pmu_start_txn
;
7687 pmu
->commit_txn
= perf_pmu_commit_txn
;
7688 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7690 pmu
->start_txn
= perf_pmu_nop_txn
;
7691 pmu
->commit_txn
= perf_pmu_nop_int
;
7692 pmu
->cancel_txn
= perf_pmu_nop_void
;
7696 if (!pmu
->pmu_enable
) {
7697 pmu
->pmu_enable
= perf_pmu_nop_void
;
7698 pmu
->pmu_disable
= perf_pmu_nop_void
;
7701 if (!pmu
->event_idx
)
7702 pmu
->event_idx
= perf_event_idx_default
;
7704 list_add_rcu(&pmu
->entry
, &pmus
);
7705 atomic_set(&pmu
->exclusive_cnt
, 0);
7708 mutex_unlock(&pmus_lock
);
7713 device_del(pmu
->dev
);
7714 put_device(pmu
->dev
);
7717 if (pmu
->type
>= PERF_TYPE_MAX
)
7718 idr_remove(&pmu_idr
, pmu
->type
);
7721 free_percpu(pmu
->pmu_disable_count
);
7724 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7726 void perf_pmu_unregister(struct pmu
*pmu
)
7728 mutex_lock(&pmus_lock
);
7729 list_del_rcu(&pmu
->entry
);
7730 mutex_unlock(&pmus_lock
);
7733 * We dereference the pmu list under both SRCU and regular RCU, so
7734 * synchronize against both of those.
7736 synchronize_srcu(&pmus_srcu
);
7739 free_percpu(pmu
->pmu_disable_count
);
7740 if (pmu
->type
>= PERF_TYPE_MAX
)
7741 idr_remove(&pmu_idr
, pmu
->type
);
7742 device_del(pmu
->dev
);
7743 put_device(pmu
->dev
);
7744 free_pmu_context(pmu
);
7746 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7748 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7750 struct perf_event_context
*ctx
= NULL
;
7753 if (!try_module_get(pmu
->module
))
7756 if (event
->group_leader
!= event
) {
7758 * This ctx->mutex can nest when we're called through
7759 * inheritance. See the perf_event_ctx_lock_nested() comment.
7761 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7762 SINGLE_DEPTH_NESTING
);
7767 ret
= pmu
->event_init(event
);
7770 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7773 module_put(pmu
->module
);
7778 static struct pmu
*perf_init_event(struct perf_event
*event
)
7780 struct pmu
*pmu
= NULL
;
7784 idx
= srcu_read_lock(&pmus_srcu
);
7787 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7790 ret
= perf_try_init_event(pmu
, event
);
7796 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7797 ret
= perf_try_init_event(pmu
, event
);
7801 if (ret
!= -ENOENT
) {
7806 pmu
= ERR_PTR(-ENOENT
);
7808 srcu_read_unlock(&pmus_srcu
, idx
);
7813 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7818 if (is_cgroup_event(event
))
7819 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7822 static void account_event(struct perf_event
*event
)
7827 if (event
->attach_state
& PERF_ATTACH_TASK
)
7828 static_key_slow_inc(&perf_sched_events
.key
);
7829 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7830 atomic_inc(&nr_mmap_events
);
7831 if (event
->attr
.comm
)
7832 atomic_inc(&nr_comm_events
);
7833 if (event
->attr
.task
)
7834 atomic_inc(&nr_task_events
);
7835 if (event
->attr
.freq
) {
7836 if (atomic_inc_return(&nr_freq_events
) == 1)
7837 tick_nohz_full_kick_all();
7839 if (event
->attr
.context_switch
) {
7840 atomic_inc(&nr_switch_events
);
7841 static_key_slow_inc(&perf_sched_events
.key
);
7843 if (has_branch_stack(event
))
7844 static_key_slow_inc(&perf_sched_events
.key
);
7845 if (is_cgroup_event(event
))
7846 static_key_slow_inc(&perf_sched_events
.key
);
7848 account_event_cpu(event
, event
->cpu
);
7852 * Allocate and initialize a event structure
7854 static struct perf_event
*
7855 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7856 struct task_struct
*task
,
7857 struct perf_event
*group_leader
,
7858 struct perf_event
*parent_event
,
7859 perf_overflow_handler_t overflow_handler
,
7860 void *context
, int cgroup_fd
)
7863 struct perf_event
*event
;
7864 struct hw_perf_event
*hwc
;
7867 if ((unsigned)cpu
>= nr_cpu_ids
) {
7868 if (!task
|| cpu
!= -1)
7869 return ERR_PTR(-EINVAL
);
7872 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7874 return ERR_PTR(-ENOMEM
);
7877 * Single events are their own group leaders, with an
7878 * empty sibling list:
7881 group_leader
= event
;
7883 mutex_init(&event
->child_mutex
);
7884 INIT_LIST_HEAD(&event
->child_list
);
7886 INIT_LIST_HEAD(&event
->group_entry
);
7887 INIT_LIST_HEAD(&event
->event_entry
);
7888 INIT_LIST_HEAD(&event
->sibling_list
);
7889 INIT_LIST_HEAD(&event
->rb_entry
);
7890 INIT_LIST_HEAD(&event
->active_entry
);
7891 INIT_HLIST_NODE(&event
->hlist_entry
);
7894 init_waitqueue_head(&event
->waitq
);
7895 init_irq_work(&event
->pending
, perf_pending_event
);
7897 mutex_init(&event
->mmap_mutex
);
7899 atomic_long_set(&event
->refcount
, 1);
7901 event
->attr
= *attr
;
7902 event
->group_leader
= group_leader
;
7906 event
->parent
= parent_event
;
7908 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7909 event
->id
= atomic64_inc_return(&perf_event_id
);
7911 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7914 event
->attach_state
= PERF_ATTACH_TASK
;
7916 * XXX pmu::event_init needs to know what task to account to
7917 * and we cannot use the ctx information because we need the
7918 * pmu before we get a ctx.
7920 event
->hw
.target
= task
;
7923 event
->clock
= &local_clock
;
7925 event
->clock
= parent_event
->clock
;
7927 if (!overflow_handler
&& parent_event
) {
7928 overflow_handler
= parent_event
->overflow_handler
;
7929 context
= parent_event
->overflow_handler_context
;
7932 event
->overflow_handler
= overflow_handler
;
7933 event
->overflow_handler_context
= context
;
7935 perf_event__state_init(event
);
7940 hwc
->sample_period
= attr
->sample_period
;
7941 if (attr
->freq
&& attr
->sample_freq
)
7942 hwc
->sample_period
= 1;
7943 hwc
->last_period
= hwc
->sample_period
;
7945 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7948 * we currently do not support PERF_FORMAT_GROUP on inherited events
7950 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7953 if (!has_branch_stack(event
))
7954 event
->attr
.branch_sample_type
= 0;
7956 if (cgroup_fd
!= -1) {
7957 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7962 pmu
= perf_init_event(event
);
7965 else if (IS_ERR(pmu
)) {
7970 err
= exclusive_event_init(event
);
7974 if (!event
->parent
) {
7975 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7976 err
= get_callchain_buffers();
7985 exclusive_event_destroy(event
);
7989 event
->destroy(event
);
7990 module_put(pmu
->module
);
7992 if (is_cgroup_event(event
))
7993 perf_detach_cgroup(event
);
7995 put_pid_ns(event
->ns
);
7998 return ERR_PTR(err
);
8001 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
8002 struct perf_event_attr
*attr
)
8007 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
8011 * zero the full structure, so that a short copy will be nice.
8013 memset(attr
, 0, sizeof(*attr
));
8015 ret
= get_user(size
, &uattr
->size
);
8019 if (size
> PAGE_SIZE
) /* silly large */
8022 if (!size
) /* abi compat */
8023 size
= PERF_ATTR_SIZE_VER0
;
8025 if (size
< PERF_ATTR_SIZE_VER0
)
8029 * If we're handed a bigger struct than we know of,
8030 * ensure all the unknown bits are 0 - i.e. new
8031 * user-space does not rely on any kernel feature
8032 * extensions we dont know about yet.
8034 if (size
> sizeof(*attr
)) {
8035 unsigned char __user
*addr
;
8036 unsigned char __user
*end
;
8039 addr
= (void __user
*)uattr
+ sizeof(*attr
);
8040 end
= (void __user
*)uattr
+ size
;
8042 for (; addr
< end
; addr
++) {
8043 ret
= get_user(val
, addr
);
8049 size
= sizeof(*attr
);
8052 ret
= copy_from_user(attr
, uattr
, size
);
8056 if (attr
->__reserved_1
)
8059 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8062 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8065 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8066 u64 mask
= attr
->branch_sample_type
;
8068 /* only using defined bits */
8069 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8072 /* at least one branch bit must be set */
8073 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8076 /* propagate priv level, when not set for branch */
8077 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8079 /* exclude_kernel checked on syscall entry */
8080 if (!attr
->exclude_kernel
)
8081 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8083 if (!attr
->exclude_user
)
8084 mask
|= PERF_SAMPLE_BRANCH_USER
;
8086 if (!attr
->exclude_hv
)
8087 mask
|= PERF_SAMPLE_BRANCH_HV
;
8089 * adjust user setting (for HW filter setup)
8091 attr
->branch_sample_type
= mask
;
8093 /* privileged levels capture (kernel, hv): check permissions */
8094 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8095 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8099 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8100 ret
= perf_reg_validate(attr
->sample_regs_user
);
8105 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8106 if (!arch_perf_have_user_stack_dump())
8110 * We have __u32 type for the size, but so far
8111 * we can only use __u16 as maximum due to the
8112 * __u16 sample size limit.
8114 if (attr
->sample_stack_user
>= USHRT_MAX
)
8116 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8120 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8121 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8126 put_user(sizeof(*attr
), &uattr
->size
);
8132 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8134 struct ring_buffer
*rb
= NULL
;
8140 /* don't allow circular references */
8141 if (event
== output_event
)
8145 * Don't allow cross-cpu buffers
8147 if (output_event
->cpu
!= event
->cpu
)
8151 * If its not a per-cpu rb, it must be the same task.
8153 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8157 * Mixing clocks in the same buffer is trouble you don't need.
8159 if (output_event
->clock
!= event
->clock
)
8163 * If both events generate aux data, they must be on the same PMU
8165 if (has_aux(event
) && has_aux(output_event
) &&
8166 event
->pmu
!= output_event
->pmu
)
8170 mutex_lock(&event
->mmap_mutex
);
8171 /* Can't redirect output if we've got an active mmap() */
8172 if (atomic_read(&event
->mmap_count
))
8176 /* get the rb we want to redirect to */
8177 rb
= ring_buffer_get(output_event
);
8182 ring_buffer_attach(event
, rb
);
8186 mutex_unlock(&event
->mmap_mutex
);
8192 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8198 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8201 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8203 bool nmi_safe
= false;
8206 case CLOCK_MONOTONIC
:
8207 event
->clock
= &ktime_get_mono_fast_ns
;
8211 case CLOCK_MONOTONIC_RAW
:
8212 event
->clock
= &ktime_get_raw_fast_ns
;
8216 case CLOCK_REALTIME
:
8217 event
->clock
= &ktime_get_real_ns
;
8220 case CLOCK_BOOTTIME
:
8221 event
->clock
= &ktime_get_boot_ns
;
8225 event
->clock
= &ktime_get_tai_ns
;
8232 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8239 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8241 * @attr_uptr: event_id type attributes for monitoring/sampling
8244 * @group_fd: group leader event fd
8246 SYSCALL_DEFINE5(perf_event_open
,
8247 struct perf_event_attr __user
*, attr_uptr
,
8248 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8250 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8251 struct perf_event
*event
, *sibling
;
8252 struct perf_event_attr attr
;
8253 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8254 struct file
*event_file
= NULL
;
8255 struct fd group
= {NULL
, 0};
8256 struct task_struct
*task
= NULL
;
8261 int f_flags
= O_RDWR
;
8264 /* for future expandability... */
8265 if (flags
& ~PERF_FLAG_ALL
)
8268 err
= perf_copy_attr(attr_uptr
, &attr
);
8272 if (!attr
.exclude_kernel
) {
8273 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8278 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8281 if (attr
.sample_period
& (1ULL << 63))
8286 * In cgroup mode, the pid argument is used to pass the fd
8287 * opened to the cgroup directory in cgroupfs. The cpu argument
8288 * designates the cpu on which to monitor threads from that
8291 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8294 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8295 f_flags
|= O_CLOEXEC
;
8297 event_fd
= get_unused_fd_flags(f_flags
);
8301 if (group_fd
!= -1) {
8302 err
= perf_fget_light(group_fd
, &group
);
8305 group_leader
= group
.file
->private_data
;
8306 if (flags
& PERF_FLAG_FD_OUTPUT
)
8307 output_event
= group_leader
;
8308 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8309 group_leader
= NULL
;
8312 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8313 task
= find_lively_task_by_vpid(pid
);
8315 err
= PTR_ERR(task
);
8320 if (task
&& group_leader
&&
8321 group_leader
->attr
.inherit
!= attr
.inherit
) {
8328 if (flags
& PERF_FLAG_PID_CGROUP
)
8331 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8332 NULL
, NULL
, cgroup_fd
);
8333 if (IS_ERR(event
)) {
8334 err
= PTR_ERR(event
);
8338 if (is_sampling_event(event
)) {
8339 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8345 account_event(event
);
8348 * Special case software events and allow them to be part of
8349 * any hardware group.
8353 if (attr
.use_clockid
) {
8354 err
= perf_event_set_clock(event
, attr
.clockid
);
8360 (is_software_event(event
) != is_software_event(group_leader
))) {
8361 if (is_software_event(event
)) {
8363 * If event and group_leader are not both a software
8364 * event, and event is, then group leader is not.
8366 * Allow the addition of software events to !software
8367 * groups, this is safe because software events never
8370 pmu
= group_leader
->pmu
;
8371 } else if (is_software_event(group_leader
) &&
8372 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8374 * In case the group is a pure software group, and we
8375 * try to add a hardware event, move the whole group to
8376 * the hardware context.
8383 * Get the target context (task or percpu):
8385 ctx
= find_get_context(pmu
, task
, event
);
8391 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8397 put_task_struct(task
);
8402 * Look up the group leader (we will attach this event to it):
8408 * Do not allow a recursive hierarchy (this new sibling
8409 * becoming part of another group-sibling):
8411 if (group_leader
->group_leader
!= group_leader
)
8414 /* All events in a group should have the same clock */
8415 if (group_leader
->clock
!= event
->clock
)
8419 * Do not allow to attach to a group in a different
8420 * task or CPU context:
8424 * Make sure we're both on the same task, or both
8427 if (group_leader
->ctx
->task
!= ctx
->task
)
8431 * Make sure we're both events for the same CPU;
8432 * grouping events for different CPUs is broken; since
8433 * you can never concurrently schedule them anyhow.
8435 if (group_leader
->cpu
!= event
->cpu
)
8438 if (group_leader
->ctx
!= ctx
)
8443 * Only a group leader can be exclusive or pinned
8445 if (attr
.exclusive
|| attr
.pinned
)
8450 err
= perf_event_set_output(event
, output_event
);
8455 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8457 if (IS_ERR(event_file
)) {
8458 err
= PTR_ERR(event_file
);
8463 gctx
= group_leader
->ctx
;
8464 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8466 mutex_lock(&ctx
->mutex
);
8469 if (!perf_event_validate_size(event
)) {
8475 * Must be under the same ctx::mutex as perf_install_in_context(),
8476 * because we need to serialize with concurrent event creation.
8478 if (!exclusive_event_installable(event
, ctx
)) {
8479 /* exclusive and group stuff are assumed mutually exclusive */
8480 WARN_ON_ONCE(move_group
);
8486 WARN_ON_ONCE(ctx
->parent_ctx
);
8490 * See perf_event_ctx_lock() for comments on the details
8491 * of swizzling perf_event::ctx.
8493 perf_remove_from_context(group_leader
, false);
8495 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8497 perf_remove_from_context(sibling
, false);
8502 * Wait for everybody to stop referencing the events through
8503 * the old lists, before installing it on new lists.
8508 * Install the group siblings before the group leader.
8510 * Because a group leader will try and install the entire group
8511 * (through the sibling list, which is still in-tact), we can
8512 * end up with siblings installed in the wrong context.
8514 * By installing siblings first we NO-OP because they're not
8515 * reachable through the group lists.
8517 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8519 perf_event__state_init(sibling
);
8520 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8525 * Removing from the context ends up with disabled
8526 * event. What we want here is event in the initial
8527 * startup state, ready to be add into new context.
8529 perf_event__state_init(group_leader
);
8530 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8534 * Now that all events are installed in @ctx, nothing
8535 * references @gctx anymore, so drop the last reference we have
8542 * Precalculate sample_data sizes; do while holding ctx::mutex such
8543 * that we're serialized against further additions and before
8544 * perf_install_in_context() which is the point the event is active and
8545 * can use these values.
8547 perf_event__header_size(event
);
8548 perf_event__id_header_size(event
);
8550 perf_install_in_context(ctx
, event
, event
->cpu
);
8551 perf_unpin_context(ctx
);
8554 mutex_unlock(&gctx
->mutex
);
8555 mutex_unlock(&ctx
->mutex
);
8559 event
->owner
= current
;
8561 mutex_lock(¤t
->perf_event_mutex
);
8562 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8563 mutex_unlock(¤t
->perf_event_mutex
);
8566 * Drop the reference on the group_event after placing the
8567 * new event on the sibling_list. This ensures destruction
8568 * of the group leader will find the pointer to itself in
8569 * perf_group_detach().
8572 fd_install(event_fd
, event_file
);
8577 mutex_unlock(&gctx
->mutex
);
8578 mutex_unlock(&ctx
->mutex
);
8582 perf_unpin_context(ctx
);
8590 put_task_struct(task
);
8594 put_unused_fd(event_fd
);
8599 * perf_event_create_kernel_counter
8601 * @attr: attributes of the counter to create
8602 * @cpu: cpu in which the counter is bound
8603 * @task: task to profile (NULL for percpu)
8606 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8607 struct task_struct
*task
,
8608 perf_overflow_handler_t overflow_handler
,
8611 struct perf_event_context
*ctx
;
8612 struct perf_event
*event
;
8616 * Get the target context (task or percpu):
8619 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8620 overflow_handler
, context
, -1);
8621 if (IS_ERR(event
)) {
8622 err
= PTR_ERR(event
);
8626 /* Mark owner so we could distinguish it from user events. */
8627 event
->owner
= EVENT_OWNER_KERNEL
;
8629 account_event(event
);
8631 ctx
= find_get_context(event
->pmu
, task
, event
);
8637 WARN_ON_ONCE(ctx
->parent_ctx
);
8638 mutex_lock(&ctx
->mutex
);
8639 if (!exclusive_event_installable(event
, ctx
)) {
8640 mutex_unlock(&ctx
->mutex
);
8641 perf_unpin_context(ctx
);
8647 perf_install_in_context(ctx
, event
, cpu
);
8648 perf_unpin_context(ctx
);
8649 mutex_unlock(&ctx
->mutex
);
8656 return ERR_PTR(err
);
8658 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8660 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8662 struct perf_event_context
*src_ctx
;
8663 struct perf_event_context
*dst_ctx
;
8664 struct perf_event
*event
, *tmp
;
8667 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8668 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8671 * See perf_event_ctx_lock() for comments on the details
8672 * of swizzling perf_event::ctx.
8674 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8675 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8677 perf_remove_from_context(event
, false);
8678 unaccount_event_cpu(event
, src_cpu
);
8680 list_add(&event
->migrate_entry
, &events
);
8684 * Wait for the events to quiesce before re-instating them.
8689 * Re-instate events in 2 passes.
8691 * Skip over group leaders and only install siblings on this first
8692 * pass, siblings will not get enabled without a leader, however a
8693 * leader will enable its siblings, even if those are still on the old
8696 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8697 if (event
->group_leader
== event
)
8700 list_del(&event
->migrate_entry
);
8701 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8702 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8703 account_event_cpu(event
, dst_cpu
);
8704 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8709 * Once all the siblings are setup properly, install the group leaders
8712 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8713 list_del(&event
->migrate_entry
);
8714 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8715 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8716 account_event_cpu(event
, dst_cpu
);
8717 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8720 mutex_unlock(&dst_ctx
->mutex
);
8721 mutex_unlock(&src_ctx
->mutex
);
8723 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8725 static void sync_child_event(struct perf_event
*child_event
,
8726 struct task_struct
*child
)
8728 struct perf_event
*parent_event
= child_event
->parent
;
8731 if (child_event
->attr
.inherit_stat
)
8732 perf_event_read_event(child_event
, child
);
8734 child_val
= perf_event_count(child_event
);
8737 * Add back the child's count to the parent's count:
8739 atomic64_add(child_val
, &parent_event
->child_count
);
8740 atomic64_add(child_event
->total_time_enabled
,
8741 &parent_event
->child_total_time_enabled
);
8742 atomic64_add(child_event
->total_time_running
,
8743 &parent_event
->child_total_time_running
);
8746 * Remove this event from the parent's list
8748 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8749 mutex_lock(&parent_event
->child_mutex
);
8750 list_del_init(&child_event
->child_list
);
8751 mutex_unlock(&parent_event
->child_mutex
);
8754 * Make sure user/parent get notified, that we just
8757 perf_event_wakeup(parent_event
);
8760 * Release the parent event, if this was the last
8763 put_event(parent_event
);
8767 __perf_event_exit_task(struct perf_event
*child_event
,
8768 struct perf_event_context
*child_ctx
,
8769 struct task_struct
*child
)
8772 * Do not destroy the 'original' grouping; because of the context
8773 * switch optimization the original events could've ended up in a
8774 * random child task.
8776 * If we were to destroy the original group, all group related
8777 * operations would cease to function properly after this random
8780 * Do destroy all inherited groups, we don't care about those
8781 * and being thorough is better.
8783 perf_remove_from_context(child_event
, !!child_event
->parent
);
8786 * It can happen that the parent exits first, and has events
8787 * that are still around due to the child reference. These
8788 * events need to be zapped.
8790 if (child_event
->parent
) {
8791 sync_child_event(child_event
, child
);
8792 free_event(child_event
);
8794 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8795 perf_event_wakeup(child_event
);
8799 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8801 struct perf_event
*child_event
, *next
;
8802 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8803 unsigned long flags
;
8805 if (likely(!child
->perf_event_ctxp
[ctxn
]))
8808 local_irq_save(flags
);
8810 * We can't reschedule here because interrupts are disabled,
8811 * and either child is current or it is a task that can't be
8812 * scheduled, so we are now safe from rescheduling changing
8815 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8818 * Take the context lock here so that if find_get_context is
8819 * reading child->perf_event_ctxp, we wait until it has
8820 * incremented the context's refcount before we do put_ctx below.
8822 raw_spin_lock(&child_ctx
->lock
);
8823 task_ctx_sched_out(child_ctx
);
8824 child
->perf_event_ctxp
[ctxn
] = NULL
;
8827 * If this context is a clone; unclone it so it can't get
8828 * swapped to another process while we're removing all
8829 * the events from it.
8831 clone_ctx
= unclone_ctx(child_ctx
);
8832 update_context_time(child_ctx
);
8833 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8839 * Report the task dead after unscheduling the events so that we
8840 * won't get any samples after PERF_RECORD_EXIT. We can however still
8841 * get a few PERF_RECORD_READ events.
8843 perf_event_task(child
, child_ctx
, 0);
8846 * We can recurse on the same lock type through:
8848 * __perf_event_exit_task()
8849 * sync_child_event()
8851 * mutex_lock(&ctx->mutex)
8853 * But since its the parent context it won't be the same instance.
8855 mutex_lock(&child_ctx
->mutex
);
8857 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8858 __perf_event_exit_task(child_event
, child_ctx
, child
);
8860 mutex_unlock(&child_ctx
->mutex
);
8866 * When a child task exits, feed back event values to parent events.
8868 void perf_event_exit_task(struct task_struct
*child
)
8870 struct perf_event
*event
, *tmp
;
8873 mutex_lock(&child
->perf_event_mutex
);
8874 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8876 list_del_init(&event
->owner_entry
);
8879 * Ensure the list deletion is visible before we clear
8880 * the owner, closes a race against perf_release() where
8881 * we need to serialize on the owner->perf_event_mutex.
8884 event
->owner
= NULL
;
8886 mutex_unlock(&child
->perf_event_mutex
);
8888 for_each_task_context_nr(ctxn
)
8889 perf_event_exit_task_context(child
, ctxn
);
8892 * The perf_event_exit_task_context calls perf_event_task
8893 * with child's task_ctx, which generates EXIT events for
8894 * child contexts and sets child->perf_event_ctxp[] to NULL.
8895 * At this point we need to send EXIT events to cpu contexts.
8897 perf_event_task(child
, NULL
, 0);
8900 static void perf_free_event(struct perf_event
*event
,
8901 struct perf_event_context
*ctx
)
8903 struct perf_event
*parent
= event
->parent
;
8905 if (WARN_ON_ONCE(!parent
))
8908 mutex_lock(&parent
->child_mutex
);
8909 list_del_init(&event
->child_list
);
8910 mutex_unlock(&parent
->child_mutex
);
8914 raw_spin_lock_irq(&ctx
->lock
);
8915 perf_group_detach(event
);
8916 list_del_event(event
, ctx
);
8917 raw_spin_unlock_irq(&ctx
->lock
);
8922 * Free an unexposed, unused context as created by inheritance by
8923 * perf_event_init_task below, used by fork() in case of fail.
8925 * Not all locks are strictly required, but take them anyway to be nice and
8926 * help out with the lockdep assertions.
8928 void perf_event_free_task(struct task_struct
*task
)
8930 struct perf_event_context
*ctx
;
8931 struct perf_event
*event
, *tmp
;
8934 for_each_task_context_nr(ctxn
) {
8935 ctx
= task
->perf_event_ctxp
[ctxn
];
8939 mutex_lock(&ctx
->mutex
);
8941 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8943 perf_free_event(event
, ctx
);
8945 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8947 perf_free_event(event
, ctx
);
8949 if (!list_empty(&ctx
->pinned_groups
) ||
8950 !list_empty(&ctx
->flexible_groups
))
8953 mutex_unlock(&ctx
->mutex
);
8959 void perf_event_delayed_put(struct task_struct
*task
)
8963 for_each_task_context_nr(ctxn
)
8964 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8967 struct perf_event
*perf_event_get(unsigned int fd
)
8971 struct perf_event
*event
;
8973 err
= perf_fget_light(fd
, &f
);
8975 return ERR_PTR(err
);
8977 event
= f
.file
->private_data
;
8978 atomic_long_inc(&event
->refcount
);
8984 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8987 return ERR_PTR(-EINVAL
);
8989 return &event
->attr
;
8993 * inherit a event from parent task to child task:
8995 static struct perf_event
*
8996 inherit_event(struct perf_event
*parent_event
,
8997 struct task_struct
*parent
,
8998 struct perf_event_context
*parent_ctx
,
8999 struct task_struct
*child
,
9000 struct perf_event
*group_leader
,
9001 struct perf_event_context
*child_ctx
)
9003 enum perf_event_active_state parent_state
= parent_event
->state
;
9004 struct perf_event
*child_event
;
9005 unsigned long flags
;
9008 * Instead of creating recursive hierarchies of events,
9009 * we link inherited events back to the original parent,
9010 * which has a filp for sure, which we use as the reference
9013 if (parent_event
->parent
)
9014 parent_event
= parent_event
->parent
;
9016 child_event
= perf_event_alloc(&parent_event
->attr
,
9019 group_leader
, parent_event
,
9021 if (IS_ERR(child_event
))
9024 if (is_orphaned_event(parent_event
) ||
9025 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
9026 free_event(child_event
);
9033 * Make the child state follow the state of the parent event,
9034 * not its attr.disabled bit. We hold the parent's mutex,
9035 * so we won't race with perf_event_{en, dis}able_family.
9037 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
9038 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
9040 child_event
->state
= PERF_EVENT_STATE_OFF
;
9042 if (parent_event
->attr
.freq
) {
9043 u64 sample_period
= parent_event
->hw
.sample_period
;
9044 struct hw_perf_event
*hwc
= &child_event
->hw
;
9046 hwc
->sample_period
= sample_period
;
9047 hwc
->last_period
= sample_period
;
9049 local64_set(&hwc
->period_left
, sample_period
);
9052 child_event
->ctx
= child_ctx
;
9053 child_event
->overflow_handler
= parent_event
->overflow_handler
;
9054 child_event
->overflow_handler_context
9055 = parent_event
->overflow_handler_context
;
9058 * Precalculate sample_data sizes
9060 perf_event__header_size(child_event
);
9061 perf_event__id_header_size(child_event
);
9064 * Link it up in the child's context:
9066 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9067 add_event_to_ctx(child_event
, child_ctx
);
9068 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9071 * Link this into the parent event's child list
9073 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9074 mutex_lock(&parent_event
->child_mutex
);
9075 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9076 mutex_unlock(&parent_event
->child_mutex
);
9081 static int inherit_group(struct perf_event
*parent_event
,
9082 struct task_struct
*parent
,
9083 struct perf_event_context
*parent_ctx
,
9084 struct task_struct
*child
,
9085 struct perf_event_context
*child_ctx
)
9087 struct perf_event
*leader
;
9088 struct perf_event
*sub
;
9089 struct perf_event
*child_ctr
;
9091 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9092 child
, NULL
, child_ctx
);
9094 return PTR_ERR(leader
);
9095 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9096 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9097 child
, leader
, child_ctx
);
9098 if (IS_ERR(child_ctr
))
9099 return PTR_ERR(child_ctr
);
9105 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9106 struct perf_event_context
*parent_ctx
,
9107 struct task_struct
*child
, int ctxn
,
9111 struct perf_event_context
*child_ctx
;
9113 if (!event
->attr
.inherit
) {
9118 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9121 * This is executed from the parent task context, so
9122 * inherit events that have been marked for cloning.
9123 * First allocate and initialize a context for the
9127 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9131 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9134 ret
= inherit_group(event
, parent
, parent_ctx
,
9144 * Initialize the perf_event context in task_struct
9146 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9148 struct perf_event_context
*child_ctx
, *parent_ctx
;
9149 struct perf_event_context
*cloned_ctx
;
9150 struct perf_event
*event
;
9151 struct task_struct
*parent
= current
;
9152 int inherited_all
= 1;
9153 unsigned long flags
;
9156 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9160 * If the parent's context is a clone, pin it so it won't get
9163 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9168 * No need to check if parent_ctx != NULL here; since we saw
9169 * it non-NULL earlier, the only reason for it to become NULL
9170 * is if we exit, and since we're currently in the middle of
9171 * a fork we can't be exiting at the same time.
9175 * Lock the parent list. No need to lock the child - not PID
9176 * hashed yet and not running, so nobody can access it.
9178 mutex_lock(&parent_ctx
->mutex
);
9181 * We dont have to disable NMIs - we are only looking at
9182 * the list, not manipulating it:
9184 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9185 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9186 child
, ctxn
, &inherited_all
);
9192 * We can't hold ctx->lock when iterating the ->flexible_group list due
9193 * to allocations, but we need to prevent rotation because
9194 * rotate_ctx() will change the list from interrupt context.
9196 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9197 parent_ctx
->rotate_disable
= 1;
9198 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9200 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9201 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9202 child
, ctxn
, &inherited_all
);
9207 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9208 parent_ctx
->rotate_disable
= 0;
9210 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9212 if (child_ctx
&& inherited_all
) {
9214 * Mark the child context as a clone of the parent
9215 * context, or of whatever the parent is a clone of.
9217 * Note that if the parent is a clone, the holding of
9218 * parent_ctx->lock avoids it from being uncloned.
9220 cloned_ctx
= parent_ctx
->parent_ctx
;
9222 child_ctx
->parent_ctx
= cloned_ctx
;
9223 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9225 child_ctx
->parent_ctx
= parent_ctx
;
9226 child_ctx
->parent_gen
= parent_ctx
->generation
;
9228 get_ctx(child_ctx
->parent_ctx
);
9231 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9232 mutex_unlock(&parent_ctx
->mutex
);
9234 perf_unpin_context(parent_ctx
);
9235 put_ctx(parent_ctx
);
9241 * Initialize the perf_event context in task_struct
9243 int perf_event_init_task(struct task_struct
*child
)
9247 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9248 mutex_init(&child
->perf_event_mutex
);
9249 INIT_LIST_HEAD(&child
->perf_event_list
);
9251 for_each_task_context_nr(ctxn
) {
9252 ret
= perf_event_init_context(child
, ctxn
);
9254 perf_event_free_task(child
);
9262 static void __init
perf_event_init_all_cpus(void)
9264 struct swevent_htable
*swhash
;
9267 for_each_possible_cpu(cpu
) {
9268 swhash
= &per_cpu(swevent_htable
, cpu
);
9269 mutex_init(&swhash
->hlist_mutex
);
9270 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9274 static void perf_event_init_cpu(int cpu
)
9276 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9278 mutex_lock(&swhash
->hlist_mutex
);
9279 if (swhash
->hlist_refcount
> 0) {
9280 struct swevent_hlist
*hlist
;
9282 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9284 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9286 mutex_unlock(&swhash
->hlist_mutex
);
9289 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9290 static void __perf_event_exit_context(void *__info
)
9292 struct remove_event re
= { .detach_group
= true };
9293 struct perf_event_context
*ctx
= __info
;
9296 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
9297 __perf_remove_from_context(&re
);
9301 static void perf_event_exit_cpu_context(int cpu
)
9303 struct perf_event_context
*ctx
;
9307 idx
= srcu_read_lock(&pmus_srcu
);
9308 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9309 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9311 mutex_lock(&ctx
->mutex
);
9312 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9313 mutex_unlock(&ctx
->mutex
);
9315 srcu_read_unlock(&pmus_srcu
, idx
);
9318 static void perf_event_exit_cpu(int cpu
)
9320 perf_event_exit_cpu_context(cpu
);
9323 static inline void perf_event_exit_cpu(int cpu
) { }
9327 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9331 for_each_online_cpu(cpu
)
9332 perf_event_exit_cpu(cpu
);
9338 * Run the perf reboot notifier at the very last possible moment so that
9339 * the generic watchdog code runs as long as possible.
9341 static struct notifier_block perf_reboot_notifier
= {
9342 .notifier_call
= perf_reboot
,
9343 .priority
= INT_MIN
,
9347 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9349 unsigned int cpu
= (long)hcpu
;
9351 switch (action
& ~CPU_TASKS_FROZEN
) {
9353 case CPU_UP_PREPARE
:
9354 case CPU_DOWN_FAILED
:
9355 perf_event_init_cpu(cpu
);
9358 case CPU_UP_CANCELED
:
9359 case CPU_DOWN_PREPARE
:
9360 perf_event_exit_cpu(cpu
);
9369 void __init
perf_event_init(void)
9375 perf_event_init_all_cpus();
9376 init_srcu_struct(&pmus_srcu
);
9377 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9378 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9379 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9381 perf_cpu_notifier(perf_cpu_notify
);
9382 register_reboot_notifier(&perf_reboot_notifier
);
9384 ret
= init_hw_breakpoint();
9385 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9387 /* do not patch jump label more than once per second */
9388 jump_label_rate_limit(&perf_sched_events
, HZ
);
9391 * Build time assertion that we keep the data_head at the intended
9392 * location. IOW, validation we got the __reserved[] size right.
9394 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9398 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9401 struct perf_pmu_events_attr
*pmu_attr
=
9402 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9404 if (pmu_attr
->event_str
)
9405 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9410 static int __init
perf_event_sysfs_init(void)
9415 mutex_lock(&pmus_lock
);
9417 ret
= bus_register(&pmu_bus
);
9421 list_for_each_entry(pmu
, &pmus
, entry
) {
9422 if (!pmu
->name
|| pmu
->type
< 0)
9425 ret
= pmu_dev_alloc(pmu
);
9426 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9428 pmu_bus_running
= 1;
9432 mutex_unlock(&pmus_lock
);
9436 device_initcall(perf_event_sysfs_init
);
9438 #ifdef CONFIG_CGROUP_PERF
9439 static struct cgroup_subsys_state
*
9440 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9442 struct perf_cgroup
*jc
;
9444 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9446 return ERR_PTR(-ENOMEM
);
9448 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9451 return ERR_PTR(-ENOMEM
);
9457 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9459 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9461 free_percpu(jc
->info
);
9465 static int __perf_cgroup_move(void *info
)
9467 struct task_struct
*task
= info
;
9469 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9474 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9476 struct task_struct
*task
;
9477 struct cgroup_subsys_state
*css
;
9479 cgroup_taskset_for_each(task
, css
, tset
)
9480 task_function_call(task
, __perf_cgroup_move
, task
);
9483 struct cgroup_subsys perf_event_cgrp_subsys
= {
9484 .css_alloc
= perf_cgroup_css_alloc
,
9485 .css_free
= perf_cgroup_css_free
,
9486 .attach
= perf_cgroup_attach
,
9488 #endif /* CONFIG_CGROUP_PERF */