1 // SPDX-License-Identifier: GPL-2.0
3 * Performance events core code:
5 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
6 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
7 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
8 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
13 #include <linux/cpu.h>
14 #include <linux/smp.h>
15 #include <linux/idr.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/hash.h>
20 #include <linux/tick.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/rculist.h>
32 #include <linux/uaccess.h>
33 #include <linux/syscalls.h>
34 #include <linux/anon_inodes.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/cgroup.h>
37 #include <linux/perf_event.h>
38 #include <linux/trace_events.h>
39 #include <linux/hw_breakpoint.h>
40 #include <linux/mm_types.h>
41 #include <linux/module.h>
42 #include <linux/mman.h>
43 #include <linux/compat.h>
44 #include <linux/bpf.h>
45 #include <linux/filter.h>
46 #include <linux/namei.h>
47 #include <linux/parser.h>
48 #include <linux/sched/clock.h>
49 #include <linux/sched/mm.h>
50 #include <linux/proc_ns.h>
51 #include <linux/mount.h>
55 #include <asm/irq_regs.h>
57 typedef int (*remote_function_f
)(void *);
59 struct remote_function_call
{
60 struct task_struct
*p
;
61 remote_function_f func
;
66 static void remote_function(void *data
)
68 struct remote_function_call
*tfc
= data
;
69 struct task_struct
*p
= tfc
->p
;
73 if (task_cpu(p
) != smp_processor_id())
77 * Now that we're on right CPU with IRQs disabled, we can test
78 * if we hit the right task without races.
81 tfc
->ret
= -ESRCH
; /* No such (running) process */
86 tfc
->ret
= tfc
->func(tfc
->info
);
90 * task_function_call - call a function on the cpu on which a task runs
91 * @p: the task to evaluate
92 * @func: the function to be called
93 * @info: the function call argument
95 * Calls the function @func when the task is currently running. This might
96 * be on the current CPU, which just calls the function directly
98 * returns: @func return value, or
99 * -ESRCH - when the process isn't running
100 * -EAGAIN - when the process moved away
103 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
105 struct remote_function_call data
= {
114 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
117 } while (ret
== -EAGAIN
);
123 * cpu_function_call - call a function on the cpu
124 * @func: the function to be called
125 * @info: the function call argument
127 * Calls the function @func on the remote cpu.
129 * returns: @func return value or -ENXIO when the cpu is offline
131 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
133 struct remote_function_call data
= {
137 .ret
= -ENXIO
, /* No such CPU */
140 smp_call_function_single(cpu
, remote_function
, &data
, 1);
145 static inline struct perf_cpu_context
*
146 __get_cpu_context(struct perf_event_context
*ctx
)
148 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
151 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
152 struct perf_event_context
*ctx
)
154 raw_spin_lock(&cpuctx
->ctx
.lock
);
156 raw_spin_lock(&ctx
->lock
);
159 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
160 struct perf_event_context
*ctx
)
163 raw_spin_unlock(&ctx
->lock
);
164 raw_spin_unlock(&cpuctx
->ctx
.lock
);
167 #define TASK_TOMBSTONE ((void *)-1L)
169 static bool is_kernel_event(struct perf_event
*event
)
171 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
175 * On task ctx scheduling...
177 * When !ctx->nr_events a task context will not be scheduled. This means
178 * we can disable the scheduler hooks (for performance) without leaving
179 * pending task ctx state.
181 * This however results in two special cases:
183 * - removing the last event from a task ctx; this is relatively straight
184 * forward and is done in __perf_remove_from_context.
186 * - adding the first event to a task ctx; this is tricky because we cannot
187 * rely on ctx->is_active and therefore cannot use event_function_call().
188 * See perf_install_in_context().
190 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
193 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
194 struct perf_event_context
*, void *);
196 struct event_function_struct
{
197 struct perf_event
*event
;
202 static int event_function(void *info
)
204 struct event_function_struct
*efs
= info
;
205 struct perf_event
*event
= efs
->event
;
206 struct perf_event_context
*ctx
= event
->ctx
;
207 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
208 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
211 lockdep_assert_irqs_disabled();
213 perf_ctx_lock(cpuctx
, task_ctx
);
215 * Since we do the IPI call without holding ctx->lock things can have
216 * changed, double check we hit the task we set out to hit.
219 if (ctx
->task
!= current
) {
225 * We only use event_function_call() on established contexts,
226 * and event_function() is only ever called when active (or
227 * rather, we'll have bailed in task_function_call() or the
228 * above ctx->task != current test), therefore we must have
229 * ctx->is_active here.
231 WARN_ON_ONCE(!ctx
->is_active
);
233 * And since we have ctx->is_active, cpuctx->task_ctx must
236 WARN_ON_ONCE(task_ctx
!= ctx
);
238 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
241 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
243 perf_ctx_unlock(cpuctx
, task_ctx
);
248 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
250 struct perf_event_context
*ctx
= event
->ctx
;
251 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
252 struct event_function_struct efs
= {
258 if (!event
->parent
) {
260 * If this is a !child event, we must hold ctx::mutex to
261 * stabilize the the event->ctx relation. See
262 * perf_event_ctx_lock().
264 lockdep_assert_held(&ctx
->mutex
);
268 cpu_function_call(event
->cpu
, event_function
, &efs
);
272 if (task
== TASK_TOMBSTONE
)
276 if (!task_function_call(task
, event_function
, &efs
))
279 raw_spin_lock_irq(&ctx
->lock
);
281 * Reload the task pointer, it might have been changed by
282 * a concurrent perf_event_context_sched_out().
285 if (task
== TASK_TOMBSTONE
) {
286 raw_spin_unlock_irq(&ctx
->lock
);
289 if (ctx
->is_active
) {
290 raw_spin_unlock_irq(&ctx
->lock
);
293 func(event
, NULL
, ctx
, data
);
294 raw_spin_unlock_irq(&ctx
->lock
);
298 * Similar to event_function_call() + event_function(), but hard assumes IRQs
299 * are already disabled and we're on the right CPU.
301 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
303 struct perf_event_context
*ctx
= event
->ctx
;
304 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
305 struct task_struct
*task
= READ_ONCE(ctx
->task
);
306 struct perf_event_context
*task_ctx
= NULL
;
308 lockdep_assert_irqs_disabled();
311 if (task
== TASK_TOMBSTONE
)
317 perf_ctx_lock(cpuctx
, task_ctx
);
320 if (task
== TASK_TOMBSTONE
)
325 * We must be either inactive or active and the right task,
326 * otherwise we're screwed, since we cannot IPI to somewhere
329 if (ctx
->is_active
) {
330 if (WARN_ON_ONCE(task
!= current
))
333 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
337 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
340 func(event
, cpuctx
, ctx
, data
);
342 perf_ctx_unlock(cpuctx
, task_ctx
);
345 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
346 PERF_FLAG_FD_OUTPUT |\
347 PERF_FLAG_PID_CGROUP |\
348 PERF_FLAG_FD_CLOEXEC)
351 * branch priv levels that need permission checks
353 #define PERF_SAMPLE_BRANCH_PERM_PLM \
354 (PERF_SAMPLE_BRANCH_KERNEL |\
355 PERF_SAMPLE_BRANCH_HV)
358 EVENT_FLEXIBLE
= 0x1,
361 /* see ctx_resched() for details */
363 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
367 * perf_sched_events : >0 events exist
368 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
371 static void perf_sched_delayed(struct work_struct
*work
);
372 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
373 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
374 static DEFINE_MUTEX(perf_sched_mutex
);
375 static atomic_t perf_sched_count
;
377 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
378 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
379 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
381 static atomic_t nr_mmap_events __read_mostly
;
382 static atomic_t nr_comm_events __read_mostly
;
383 static atomic_t nr_namespaces_events __read_mostly
;
384 static atomic_t nr_task_events __read_mostly
;
385 static atomic_t nr_freq_events __read_mostly
;
386 static atomic_t nr_switch_events __read_mostly
;
387 static atomic_t nr_ksymbol_events __read_mostly
;
388 static atomic_t nr_bpf_events __read_mostly
;
390 static LIST_HEAD(pmus
);
391 static DEFINE_MUTEX(pmus_lock
);
392 static struct srcu_struct pmus_srcu
;
393 static cpumask_var_t perf_online_mask
;
396 * perf event paranoia level:
397 * -1 - not paranoid at all
398 * 0 - disallow raw tracepoint access for unpriv
399 * 1 - disallow cpu events for unpriv
400 * 2 - disallow kernel profiling for unpriv
402 int sysctl_perf_event_paranoid __read_mostly
= 2;
404 /* Minimum for 512 kiB + 1 user control page */
405 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
408 * max perf event sample rate
410 #define DEFAULT_MAX_SAMPLE_RATE 100000
411 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
412 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
414 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
416 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
417 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
419 static int perf_sample_allowed_ns __read_mostly
=
420 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
422 static void update_perf_cpu_limits(void)
424 u64 tmp
= perf_sample_period_ns
;
426 tmp
*= sysctl_perf_cpu_time_max_percent
;
427 tmp
= div_u64(tmp
, 100);
431 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
434 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
);
436 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
437 void __user
*buffer
, size_t *lenp
,
441 int perf_cpu
= sysctl_perf_cpu_time_max_percent
;
443 * If throttling is disabled don't allow the write:
445 if (write
&& (perf_cpu
== 100 || perf_cpu
== 0))
448 ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
452 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
453 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
454 update_perf_cpu_limits();
459 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
461 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
462 void __user
*buffer
, size_t *lenp
,
465 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
470 if (sysctl_perf_cpu_time_max_percent
== 100 ||
471 sysctl_perf_cpu_time_max_percent
== 0) {
473 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
474 WRITE_ONCE(perf_sample_allowed_ns
, 0);
476 update_perf_cpu_limits();
483 * perf samples are done in some very critical code paths (NMIs).
484 * If they take too much CPU time, the system can lock up and not
485 * get any real work done. This will drop the sample rate when
486 * we detect that events are taking too long.
488 #define NR_ACCUMULATED_SAMPLES 128
489 static DEFINE_PER_CPU(u64
, running_sample_length
);
491 static u64 __report_avg
;
492 static u64 __report_allowed
;
494 static void perf_duration_warn(struct irq_work
*w
)
496 printk_ratelimited(KERN_INFO
497 "perf: interrupt took too long (%lld > %lld), lowering "
498 "kernel.perf_event_max_sample_rate to %d\n",
499 __report_avg
, __report_allowed
,
500 sysctl_perf_event_sample_rate
);
503 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
505 void perf_sample_event_took(u64 sample_len_ns
)
507 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
515 /* Decay the counter by 1 average sample. */
516 running_len
= __this_cpu_read(running_sample_length
);
517 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
518 running_len
+= sample_len_ns
;
519 __this_cpu_write(running_sample_length
, running_len
);
522 * Note: this will be biased artifically low until we have
523 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
524 * from having to maintain a count.
526 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
527 if (avg_len
<= max_len
)
530 __report_avg
= avg_len
;
531 __report_allowed
= max_len
;
534 * Compute a throttle threshold 25% below the current duration.
536 avg_len
+= avg_len
/ 4;
537 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
543 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
544 WRITE_ONCE(max_samples_per_tick
, max
);
546 sysctl_perf_event_sample_rate
= max
* HZ
;
547 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
549 if (!irq_work_queue(&perf_duration_work
)) {
550 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
551 "kernel.perf_event_max_sample_rate to %d\n",
552 __report_avg
, __report_allowed
,
553 sysctl_perf_event_sample_rate
);
557 static atomic64_t perf_event_id
;
559 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
560 enum event_type_t event_type
);
562 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
563 enum event_type_t event_type
,
564 struct task_struct
*task
);
566 static void update_context_time(struct perf_event_context
*ctx
);
567 static u64
perf_event_time(struct perf_event
*event
);
569 void __weak
perf_event_print_debug(void) { }
571 extern __weak
const char *perf_pmu_name(void)
576 static inline u64
perf_clock(void)
578 return local_clock();
581 static inline u64
perf_event_clock(struct perf_event
*event
)
583 return event
->clock();
587 * State based event timekeeping...
589 * The basic idea is to use event->state to determine which (if any) time
590 * fields to increment with the current delta. This means we only need to
591 * update timestamps when we change state or when they are explicitly requested
594 * Event groups make things a little more complicated, but not terribly so. The
595 * rules for a group are that if the group leader is OFF the entire group is
596 * OFF, irrespecive of what the group member states are. This results in
597 * __perf_effective_state().
599 * A futher ramification is that when a group leader flips between OFF and
600 * !OFF, we need to update all group member times.
603 * NOTE: perf_event_time() is based on the (cgroup) context time, and thus we
604 * need to make sure the relevant context time is updated before we try and
605 * update our timestamps.
608 static __always_inline
enum perf_event_state
609 __perf_effective_state(struct perf_event
*event
)
611 struct perf_event
*leader
= event
->group_leader
;
613 if (leader
->state
<= PERF_EVENT_STATE_OFF
)
614 return leader
->state
;
619 static __always_inline
void
620 __perf_update_times(struct perf_event
*event
, u64 now
, u64
*enabled
, u64
*running
)
622 enum perf_event_state state
= __perf_effective_state(event
);
623 u64 delta
= now
- event
->tstamp
;
625 *enabled
= event
->total_time_enabled
;
626 if (state
>= PERF_EVENT_STATE_INACTIVE
)
629 *running
= event
->total_time_running
;
630 if (state
>= PERF_EVENT_STATE_ACTIVE
)
634 static void perf_event_update_time(struct perf_event
*event
)
636 u64 now
= perf_event_time(event
);
638 __perf_update_times(event
, now
, &event
->total_time_enabled
,
639 &event
->total_time_running
);
643 static void perf_event_update_sibling_time(struct perf_event
*leader
)
645 struct perf_event
*sibling
;
647 for_each_sibling_event(sibling
, leader
)
648 perf_event_update_time(sibling
);
652 perf_event_set_state(struct perf_event
*event
, enum perf_event_state state
)
654 if (event
->state
== state
)
657 perf_event_update_time(event
);
659 * If a group leader gets enabled/disabled all its siblings
662 if ((event
->state
< 0) ^ (state
< 0))
663 perf_event_update_sibling_time(event
);
665 WRITE_ONCE(event
->state
, state
);
668 #ifdef CONFIG_CGROUP_PERF
671 perf_cgroup_match(struct perf_event
*event
)
673 struct perf_event_context
*ctx
= event
->ctx
;
674 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
676 /* @event doesn't care about cgroup */
680 /* wants specific cgroup scope but @cpuctx isn't associated with any */
685 * Cgroup scoping is recursive. An event enabled for a cgroup is
686 * also enabled for all its descendant cgroups. If @cpuctx's
687 * cgroup is a descendant of @event's (the test covers identity
688 * case), it's a match.
690 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
691 event
->cgrp
->css
.cgroup
);
694 static inline void perf_detach_cgroup(struct perf_event
*event
)
696 css_put(&event
->cgrp
->css
);
700 static inline int is_cgroup_event(struct perf_event
*event
)
702 return event
->cgrp
!= NULL
;
705 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
707 struct perf_cgroup_info
*t
;
709 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
713 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
715 struct perf_cgroup_info
*info
;
720 info
= this_cpu_ptr(cgrp
->info
);
722 info
->time
+= now
- info
->timestamp
;
723 info
->timestamp
= now
;
726 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
728 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
729 struct cgroup_subsys_state
*css
;
732 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
733 cgrp
= container_of(css
, struct perf_cgroup
, css
);
734 __update_cgrp_time(cgrp
);
739 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
741 struct perf_cgroup
*cgrp
;
744 * ensure we access cgroup data only when needed and
745 * when we know the cgroup is pinned (css_get)
747 if (!is_cgroup_event(event
))
750 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
752 * Do not update time when cgroup is not active
754 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
755 __update_cgrp_time(event
->cgrp
);
759 perf_cgroup_set_timestamp(struct task_struct
*task
,
760 struct perf_event_context
*ctx
)
762 struct perf_cgroup
*cgrp
;
763 struct perf_cgroup_info
*info
;
764 struct cgroup_subsys_state
*css
;
767 * ctx->lock held by caller
768 * ensure we do not access cgroup data
769 * unless we have the cgroup pinned (css_get)
771 if (!task
|| !ctx
->nr_cgroups
)
774 cgrp
= perf_cgroup_from_task(task
, ctx
);
776 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
777 cgrp
= container_of(css
, struct perf_cgroup
, css
);
778 info
= this_cpu_ptr(cgrp
->info
);
779 info
->timestamp
= ctx
->timestamp
;
783 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
785 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
786 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
789 * reschedule events based on the cgroup constraint of task.
791 * mode SWOUT : schedule out everything
792 * mode SWIN : schedule in based on cgroup for next
794 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
796 struct perf_cpu_context
*cpuctx
;
797 struct list_head
*list
;
801 * Disable interrupts and preemption to avoid this CPU's
802 * cgrp_cpuctx_entry to change under us.
804 local_irq_save(flags
);
806 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
807 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
808 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
810 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
811 perf_pmu_disable(cpuctx
->ctx
.pmu
);
813 if (mode
& PERF_CGROUP_SWOUT
) {
814 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
816 * must not be done before ctxswout due
817 * to event_filter_match() in event_sched_out()
822 if (mode
& PERF_CGROUP_SWIN
) {
823 WARN_ON_ONCE(cpuctx
->cgrp
);
825 * set cgrp before ctxsw in to allow
826 * event_filter_match() to not have to pass
828 * we pass the cpuctx->ctx to perf_cgroup_from_task()
829 * because cgorup events are only per-cpu
831 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
833 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
835 perf_pmu_enable(cpuctx
->ctx
.pmu
);
836 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
839 local_irq_restore(flags
);
842 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
843 struct task_struct
*next
)
845 struct perf_cgroup
*cgrp1
;
846 struct perf_cgroup
*cgrp2
= NULL
;
850 * we come here when we know perf_cgroup_events > 0
851 * we do not need to pass the ctx here because we know
852 * we are holding the rcu lock
854 cgrp1
= perf_cgroup_from_task(task
, NULL
);
855 cgrp2
= perf_cgroup_from_task(next
, NULL
);
858 * only schedule out current cgroup events if we know
859 * that we are switching to a different cgroup. Otherwise,
860 * do no touch the cgroup events.
863 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
868 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
869 struct task_struct
*task
)
871 struct perf_cgroup
*cgrp1
;
872 struct perf_cgroup
*cgrp2
= NULL
;
876 * we come here when we know perf_cgroup_events > 0
877 * we do not need to pass the ctx here because we know
878 * we are holding the rcu lock
880 cgrp1
= perf_cgroup_from_task(task
, NULL
);
881 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
884 * only need to schedule in cgroup events if we are changing
885 * cgroup during ctxsw. Cgroup events were not scheduled
886 * out of ctxsw out if that was not the case.
889 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
894 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
895 struct perf_event_attr
*attr
,
896 struct perf_event
*group_leader
)
898 struct perf_cgroup
*cgrp
;
899 struct cgroup_subsys_state
*css
;
900 struct fd f
= fdget(fd
);
906 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
907 &perf_event_cgrp_subsys
);
913 cgrp
= container_of(css
, struct perf_cgroup
, css
);
917 * all events in a group must monitor
918 * the same cgroup because a task belongs
919 * to only one perf cgroup at a time
921 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
922 perf_detach_cgroup(event
);
931 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
933 struct perf_cgroup_info
*t
;
934 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
935 event
->shadow_ctx_time
= now
- t
->timestamp
;
939 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
940 * cleared when last cgroup event is removed.
943 list_update_cgroup_event(struct perf_event
*event
,
944 struct perf_event_context
*ctx
, bool add
)
946 struct perf_cpu_context
*cpuctx
;
947 struct list_head
*cpuctx_entry
;
949 if (!is_cgroup_event(event
))
953 * Because cgroup events are always per-cpu events,
954 * this will always be called from the right CPU.
956 cpuctx
= __get_cpu_context(ctx
);
959 * Since setting cpuctx->cgrp is conditional on the current @cgrp
960 * matching the event's cgroup, we must do this for every new event,
961 * because if the first would mismatch, the second would not try again
962 * and we would leave cpuctx->cgrp unset.
964 if (add
&& !cpuctx
->cgrp
) {
965 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
967 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
971 if (add
&& ctx
->nr_cgroups
++)
973 else if (!add
&& --ctx
->nr_cgroups
)
976 /* no cgroup running */
980 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
982 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
984 list_del(cpuctx_entry
);
987 #else /* !CONFIG_CGROUP_PERF */
990 perf_cgroup_match(struct perf_event
*event
)
995 static inline void perf_detach_cgroup(struct perf_event
*event
)
998 static inline int is_cgroup_event(struct perf_event
*event
)
1003 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
1007 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
1011 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
1012 struct task_struct
*next
)
1016 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
1017 struct task_struct
*task
)
1021 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
1022 struct perf_event_attr
*attr
,
1023 struct perf_event
*group_leader
)
1029 perf_cgroup_set_timestamp(struct task_struct
*task
,
1030 struct perf_event_context
*ctx
)
1035 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
1040 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1044 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1050 list_update_cgroup_event(struct perf_event
*event
,
1051 struct perf_event_context
*ctx
, bool add
)
1058 * set default to be dependent on timer tick just
1059 * like original code
1061 #define PERF_CPU_HRTIMER (1000 / HZ)
1063 * function must be called with interrupts disabled
1065 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1067 struct perf_cpu_context
*cpuctx
;
1070 lockdep_assert_irqs_disabled();
1072 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1073 rotations
= perf_rotate_context(cpuctx
);
1075 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1077 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1079 cpuctx
->hrtimer_active
= 0;
1080 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1082 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1085 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1087 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1088 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1091 /* no multiplexing needed for SW PMU */
1092 if (pmu
->task_ctx_nr
== perf_sw_context
)
1096 * check default is sane, if not set then force to
1097 * default interval (1/tick)
1099 interval
= pmu
->hrtimer_interval_ms
;
1101 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1103 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1105 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1106 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED_HARD
);
1107 timer
->function
= perf_mux_hrtimer_handler
;
1110 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1112 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1113 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1114 unsigned long flags
;
1116 /* not for SW PMU */
1117 if (pmu
->task_ctx_nr
== perf_sw_context
)
1120 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1121 if (!cpuctx
->hrtimer_active
) {
1122 cpuctx
->hrtimer_active
= 1;
1123 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1124 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED_HARD
);
1126 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1131 void perf_pmu_disable(struct pmu
*pmu
)
1133 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1135 pmu
->pmu_disable(pmu
);
1138 void perf_pmu_enable(struct pmu
*pmu
)
1140 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1142 pmu
->pmu_enable(pmu
);
1145 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1148 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1149 * perf_event_task_tick() are fully serialized because they're strictly cpu
1150 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1151 * disabled, while perf_event_task_tick is called from IRQ context.
1153 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1155 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1157 lockdep_assert_irqs_disabled();
1159 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1161 list_add(&ctx
->active_ctx_list
, head
);
1164 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1166 lockdep_assert_irqs_disabled();
1168 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1170 list_del_init(&ctx
->active_ctx_list
);
1173 static void get_ctx(struct perf_event_context
*ctx
)
1175 refcount_inc(&ctx
->refcount
);
1178 static void free_ctx(struct rcu_head
*head
)
1180 struct perf_event_context
*ctx
;
1182 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1183 kfree(ctx
->task_ctx_data
);
1187 static void put_ctx(struct perf_event_context
*ctx
)
1189 if (refcount_dec_and_test(&ctx
->refcount
)) {
1190 if (ctx
->parent_ctx
)
1191 put_ctx(ctx
->parent_ctx
);
1192 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1193 put_task_struct(ctx
->task
);
1194 call_rcu(&ctx
->rcu_head
, free_ctx
);
1199 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1200 * perf_pmu_migrate_context() we need some magic.
1202 * Those places that change perf_event::ctx will hold both
1203 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1205 * Lock ordering is by mutex address. There are two other sites where
1206 * perf_event_context::mutex nests and those are:
1208 * - perf_event_exit_task_context() [ child , 0 ]
1209 * perf_event_exit_event()
1210 * put_event() [ parent, 1 ]
1212 * - perf_event_init_context() [ parent, 0 ]
1213 * inherit_task_group()
1216 * perf_event_alloc()
1218 * perf_try_init_event() [ child , 1 ]
1220 * While it appears there is an obvious deadlock here -- the parent and child
1221 * nesting levels are inverted between the two. This is in fact safe because
1222 * life-time rules separate them. That is an exiting task cannot fork, and a
1223 * spawning task cannot (yet) exit.
1225 * But remember that that these are parent<->child context relations, and
1226 * migration does not affect children, therefore these two orderings should not
1229 * The change in perf_event::ctx does not affect children (as claimed above)
1230 * because the sys_perf_event_open() case will install a new event and break
1231 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1232 * concerned with cpuctx and that doesn't have children.
1234 * The places that change perf_event::ctx will issue:
1236 * perf_remove_from_context();
1237 * synchronize_rcu();
1238 * perf_install_in_context();
1240 * to affect the change. The remove_from_context() + synchronize_rcu() should
1241 * quiesce the event, after which we can install it in the new location. This
1242 * means that only external vectors (perf_fops, prctl) can perturb the event
1243 * while in transit. Therefore all such accessors should also acquire
1244 * perf_event_context::mutex to serialize against this.
1246 * However; because event->ctx can change while we're waiting to acquire
1247 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1252 * task_struct::perf_event_mutex
1253 * perf_event_context::mutex
1254 * perf_event::child_mutex;
1255 * perf_event_context::lock
1256 * perf_event::mmap_mutex
1258 * perf_addr_filters_head::lock
1262 * cpuctx->mutex / perf_event_context::mutex
1264 static struct perf_event_context
*
1265 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1267 struct perf_event_context
*ctx
;
1271 ctx
= READ_ONCE(event
->ctx
);
1272 if (!refcount_inc_not_zero(&ctx
->refcount
)) {
1278 mutex_lock_nested(&ctx
->mutex
, nesting
);
1279 if (event
->ctx
!= ctx
) {
1280 mutex_unlock(&ctx
->mutex
);
1288 static inline struct perf_event_context
*
1289 perf_event_ctx_lock(struct perf_event
*event
)
1291 return perf_event_ctx_lock_nested(event
, 0);
1294 static void perf_event_ctx_unlock(struct perf_event
*event
,
1295 struct perf_event_context
*ctx
)
1297 mutex_unlock(&ctx
->mutex
);
1302 * This must be done under the ctx->lock, such as to serialize against
1303 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1304 * calling scheduler related locks and ctx->lock nests inside those.
1306 static __must_check
struct perf_event_context
*
1307 unclone_ctx(struct perf_event_context
*ctx
)
1309 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1311 lockdep_assert_held(&ctx
->lock
);
1314 ctx
->parent_ctx
= NULL
;
1320 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1325 * only top level events have the pid namespace they were created in
1328 event
= event
->parent
;
1330 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1331 /* avoid -1 if it is idle thread or runs in another ns */
1332 if (!nr
&& !pid_alive(p
))
1337 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1339 return perf_event_pid_type(event
, p
, PIDTYPE_TGID
);
1342 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1344 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1348 * If we inherit events we want to return the parent event id
1351 static u64
primary_event_id(struct perf_event
*event
)
1356 id
= event
->parent
->id
;
1362 * Get the perf_event_context for a task and lock it.
1364 * This has to cope with with the fact that until it is locked,
1365 * the context could get moved to another task.
1367 static struct perf_event_context
*
1368 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1370 struct perf_event_context
*ctx
;
1374 * One of the few rules of preemptible RCU is that one cannot do
1375 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1376 * part of the read side critical section was irqs-enabled -- see
1377 * rcu_read_unlock_special().
1379 * Since ctx->lock nests under rq->lock we must ensure the entire read
1380 * side critical section has interrupts disabled.
1382 local_irq_save(*flags
);
1384 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1387 * If this context is a clone of another, it might
1388 * get swapped for another underneath us by
1389 * perf_event_task_sched_out, though the
1390 * rcu_read_lock() protects us from any context
1391 * getting freed. Lock the context and check if it
1392 * got swapped before we could get the lock, and retry
1393 * if so. If we locked the right context, then it
1394 * can't get swapped on us any more.
1396 raw_spin_lock(&ctx
->lock
);
1397 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1398 raw_spin_unlock(&ctx
->lock
);
1400 local_irq_restore(*flags
);
1404 if (ctx
->task
== TASK_TOMBSTONE
||
1405 !refcount_inc_not_zero(&ctx
->refcount
)) {
1406 raw_spin_unlock(&ctx
->lock
);
1409 WARN_ON_ONCE(ctx
->task
!= task
);
1414 local_irq_restore(*flags
);
1419 * Get the context for a task and increment its pin_count so it
1420 * can't get swapped to another task. This also increments its
1421 * reference count so that the context can't get freed.
1423 static struct perf_event_context
*
1424 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1426 struct perf_event_context
*ctx
;
1427 unsigned long flags
;
1429 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1432 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1437 static void perf_unpin_context(struct perf_event_context
*ctx
)
1439 unsigned long flags
;
1441 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1443 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1447 * Update the record of the current time in a context.
1449 static void update_context_time(struct perf_event_context
*ctx
)
1451 u64 now
= perf_clock();
1453 ctx
->time
+= now
- ctx
->timestamp
;
1454 ctx
->timestamp
= now
;
1457 static u64
perf_event_time(struct perf_event
*event
)
1459 struct perf_event_context
*ctx
= event
->ctx
;
1461 if (is_cgroup_event(event
))
1462 return perf_cgroup_event_time(event
);
1464 return ctx
? ctx
->time
: 0;
1467 static enum event_type_t
get_event_type(struct perf_event
*event
)
1469 struct perf_event_context
*ctx
= event
->ctx
;
1470 enum event_type_t event_type
;
1472 lockdep_assert_held(&ctx
->lock
);
1475 * It's 'group type', really, because if our group leader is
1476 * pinned, so are we.
1478 if (event
->group_leader
!= event
)
1479 event
= event
->group_leader
;
1481 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1483 event_type
|= EVENT_CPU
;
1489 * Helper function to initialize event group nodes.
1491 static void init_event_group(struct perf_event
*event
)
1493 RB_CLEAR_NODE(&event
->group_node
);
1494 event
->group_index
= 0;
1498 * Extract pinned or flexible groups from the context
1499 * based on event attrs bits.
1501 static struct perf_event_groups
*
1502 get_event_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1504 if (event
->attr
.pinned
)
1505 return &ctx
->pinned_groups
;
1507 return &ctx
->flexible_groups
;
1511 * Helper function to initializes perf_event_group trees.
1513 static void perf_event_groups_init(struct perf_event_groups
*groups
)
1515 groups
->tree
= RB_ROOT
;
1520 * Compare function for event groups;
1522 * Implements complex key that first sorts by CPU and then by virtual index
1523 * which provides ordering when rotating groups for the same CPU.
1526 perf_event_groups_less(struct perf_event
*left
, struct perf_event
*right
)
1528 if (left
->cpu
< right
->cpu
)
1530 if (left
->cpu
> right
->cpu
)
1533 if (left
->group_index
< right
->group_index
)
1535 if (left
->group_index
> right
->group_index
)
1542 * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for
1543 * key (see perf_event_groups_less). This places it last inside the CPU
1547 perf_event_groups_insert(struct perf_event_groups
*groups
,
1548 struct perf_event
*event
)
1550 struct perf_event
*node_event
;
1551 struct rb_node
*parent
;
1552 struct rb_node
**node
;
1554 event
->group_index
= ++groups
->index
;
1556 node
= &groups
->tree
.rb_node
;
1561 node_event
= container_of(*node
, struct perf_event
, group_node
);
1563 if (perf_event_groups_less(event
, node_event
))
1564 node
= &parent
->rb_left
;
1566 node
= &parent
->rb_right
;
1569 rb_link_node(&event
->group_node
, parent
, node
);
1570 rb_insert_color(&event
->group_node
, &groups
->tree
);
1574 * Helper function to insert event into the pinned or flexible groups.
1577 add_event_to_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1579 struct perf_event_groups
*groups
;
1581 groups
= get_event_groups(event
, ctx
);
1582 perf_event_groups_insert(groups
, event
);
1586 * Delete a group from a tree.
1589 perf_event_groups_delete(struct perf_event_groups
*groups
,
1590 struct perf_event
*event
)
1592 WARN_ON_ONCE(RB_EMPTY_NODE(&event
->group_node
) ||
1593 RB_EMPTY_ROOT(&groups
->tree
));
1595 rb_erase(&event
->group_node
, &groups
->tree
);
1596 init_event_group(event
);
1600 * Helper function to delete event from its groups.
1603 del_event_from_groups(struct perf_event
*event
, struct perf_event_context
*ctx
)
1605 struct perf_event_groups
*groups
;
1607 groups
= get_event_groups(event
, ctx
);
1608 perf_event_groups_delete(groups
, event
);
1612 * Get the leftmost event in the @cpu subtree.
1614 static struct perf_event
*
1615 perf_event_groups_first(struct perf_event_groups
*groups
, int cpu
)
1617 struct perf_event
*node_event
= NULL
, *match
= NULL
;
1618 struct rb_node
*node
= groups
->tree
.rb_node
;
1621 node_event
= container_of(node
, struct perf_event
, group_node
);
1623 if (cpu
< node_event
->cpu
) {
1624 node
= node
->rb_left
;
1625 } else if (cpu
> node_event
->cpu
) {
1626 node
= node
->rb_right
;
1629 node
= node
->rb_left
;
1637 * Like rb_entry_next_safe() for the @cpu subtree.
1639 static struct perf_event
*
1640 perf_event_groups_next(struct perf_event
*event
)
1642 struct perf_event
*next
;
1644 next
= rb_entry_safe(rb_next(&event
->group_node
), typeof(*event
), group_node
);
1645 if (next
&& next
->cpu
== event
->cpu
)
1652 * Iterate through the whole groups tree.
1654 #define perf_event_groups_for_each(event, groups) \
1655 for (event = rb_entry_safe(rb_first(&((groups)->tree)), \
1656 typeof(*event), group_node); event; \
1657 event = rb_entry_safe(rb_next(&event->group_node), \
1658 typeof(*event), group_node))
1661 * Add an event from the lists for its context.
1662 * Must be called with ctx->mutex and ctx->lock held.
1665 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1667 lockdep_assert_held(&ctx
->lock
);
1669 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1670 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1672 event
->tstamp
= perf_event_time(event
);
1675 * If we're a stand alone event or group leader, we go to the context
1676 * list, group events are kept attached to the group so that
1677 * perf_group_detach can, at all times, locate all siblings.
1679 if (event
->group_leader
== event
) {
1680 event
->group_caps
= event
->event_caps
;
1681 add_event_to_groups(event
, ctx
);
1684 list_update_cgroup_event(event
, ctx
, true);
1686 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1688 if (event
->attr
.inherit_stat
)
1695 * Initialize event state based on the perf_event_attr::disabled.
1697 static inline void perf_event__state_init(struct perf_event
*event
)
1699 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1700 PERF_EVENT_STATE_INACTIVE
;
1703 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1705 int entry
= sizeof(u64
); /* value */
1709 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1710 size
+= sizeof(u64
);
1712 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1713 size
+= sizeof(u64
);
1715 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1716 entry
+= sizeof(u64
);
1718 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1720 size
+= sizeof(u64
);
1724 event
->read_size
= size
;
1727 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1729 struct perf_sample_data
*data
;
1732 if (sample_type
& PERF_SAMPLE_IP
)
1733 size
+= sizeof(data
->ip
);
1735 if (sample_type
& PERF_SAMPLE_ADDR
)
1736 size
+= sizeof(data
->addr
);
1738 if (sample_type
& PERF_SAMPLE_PERIOD
)
1739 size
+= sizeof(data
->period
);
1741 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1742 size
+= sizeof(data
->weight
);
1744 if (sample_type
& PERF_SAMPLE_READ
)
1745 size
+= event
->read_size
;
1747 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1748 size
+= sizeof(data
->data_src
.val
);
1750 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1751 size
+= sizeof(data
->txn
);
1753 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1754 size
+= sizeof(data
->phys_addr
);
1756 event
->header_size
= size
;
1760 * Called at perf_event creation and when events are attached/detached from a
1763 static void perf_event__header_size(struct perf_event
*event
)
1765 __perf_event_read_size(event
,
1766 event
->group_leader
->nr_siblings
);
1767 __perf_event_header_size(event
, event
->attr
.sample_type
);
1770 static void perf_event__id_header_size(struct perf_event
*event
)
1772 struct perf_sample_data
*data
;
1773 u64 sample_type
= event
->attr
.sample_type
;
1776 if (sample_type
& PERF_SAMPLE_TID
)
1777 size
+= sizeof(data
->tid_entry
);
1779 if (sample_type
& PERF_SAMPLE_TIME
)
1780 size
+= sizeof(data
->time
);
1782 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1783 size
+= sizeof(data
->id
);
1785 if (sample_type
& PERF_SAMPLE_ID
)
1786 size
+= sizeof(data
->id
);
1788 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1789 size
+= sizeof(data
->stream_id
);
1791 if (sample_type
& PERF_SAMPLE_CPU
)
1792 size
+= sizeof(data
->cpu_entry
);
1794 event
->id_header_size
= size
;
1797 static bool perf_event_validate_size(struct perf_event
*event
)
1800 * The values computed here will be over-written when we actually
1803 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1804 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1805 perf_event__id_header_size(event
);
1808 * Sum the lot; should not exceed the 64k limit we have on records.
1809 * Conservative limit to allow for callchains and other variable fields.
1811 if (event
->read_size
+ event
->header_size
+
1812 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1818 static void perf_group_attach(struct perf_event
*event
)
1820 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1822 lockdep_assert_held(&event
->ctx
->lock
);
1825 * We can have double attach due to group movement in perf_event_open.
1827 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1830 event
->attach_state
|= PERF_ATTACH_GROUP
;
1832 if (group_leader
== event
)
1835 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1837 group_leader
->group_caps
&= event
->event_caps
;
1839 list_add_tail(&event
->sibling_list
, &group_leader
->sibling_list
);
1840 group_leader
->nr_siblings
++;
1842 perf_event__header_size(group_leader
);
1844 for_each_sibling_event(pos
, group_leader
)
1845 perf_event__header_size(pos
);
1849 * Remove an event from the lists for its context.
1850 * Must be called with ctx->mutex and ctx->lock held.
1853 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1855 WARN_ON_ONCE(event
->ctx
!= ctx
);
1856 lockdep_assert_held(&ctx
->lock
);
1859 * We can have double detach due to exit/hot-unplug + close.
1861 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1864 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1866 list_update_cgroup_event(event
, ctx
, false);
1869 if (event
->attr
.inherit_stat
)
1872 list_del_rcu(&event
->event_entry
);
1874 if (event
->group_leader
== event
)
1875 del_event_from_groups(event
, ctx
);
1878 * If event was in error state, then keep it
1879 * that way, otherwise bogus counts will be
1880 * returned on read(). The only way to get out
1881 * of error state is by explicit re-enabling
1884 if (event
->state
> PERF_EVENT_STATE_OFF
)
1885 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
1891 perf_aux_output_match(struct perf_event
*event
, struct perf_event
*aux_event
)
1893 if (!has_aux(aux_event
))
1896 if (!event
->pmu
->aux_output_match
)
1899 return event
->pmu
->aux_output_match(aux_event
);
1902 static void put_event(struct perf_event
*event
);
1903 static void event_sched_out(struct perf_event
*event
,
1904 struct perf_cpu_context
*cpuctx
,
1905 struct perf_event_context
*ctx
);
1907 static void perf_put_aux_event(struct perf_event
*event
)
1909 struct perf_event_context
*ctx
= event
->ctx
;
1910 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1911 struct perf_event
*iter
;
1914 * If event uses aux_event tear down the link
1916 if (event
->aux_event
) {
1917 iter
= event
->aux_event
;
1918 event
->aux_event
= NULL
;
1924 * If the event is an aux_event, tear down all links to
1925 * it from other events.
1927 for_each_sibling_event(iter
, event
->group_leader
) {
1928 if (iter
->aux_event
!= event
)
1931 iter
->aux_event
= NULL
;
1935 * If it's ACTIVE, schedule it out and put it into ERROR
1936 * state so that we don't try to schedule it again. Note
1937 * that perf_event_enable() will clear the ERROR status.
1939 event_sched_out(iter
, cpuctx
, ctx
);
1940 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
1944 static int perf_get_aux_event(struct perf_event
*event
,
1945 struct perf_event
*group_leader
)
1948 * Our group leader must be an aux event if we want to be
1949 * an aux_output. This way, the aux event will precede its
1950 * aux_output events in the group, and therefore will always
1956 if (!perf_aux_output_match(event
, group_leader
))
1959 if (!atomic_long_inc_not_zero(&group_leader
->refcount
))
1963 * Link aux_outputs to their aux event; this is undone in
1964 * perf_group_detach() by perf_put_aux_event(). When the
1965 * group in torn down, the aux_output events loose their
1966 * link to the aux_event and can't schedule any more.
1968 event
->aux_event
= group_leader
;
1973 static void perf_group_detach(struct perf_event
*event
)
1975 struct perf_event
*sibling
, *tmp
;
1976 struct perf_event_context
*ctx
= event
->ctx
;
1978 lockdep_assert_held(&ctx
->lock
);
1981 * We can have double detach due to exit/hot-unplug + close.
1983 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1986 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1988 perf_put_aux_event(event
);
1991 * If this is a sibling, remove it from its group.
1993 if (event
->group_leader
!= event
) {
1994 list_del_init(&event
->sibling_list
);
1995 event
->group_leader
->nr_siblings
--;
2000 * If this was a group event with sibling events then
2001 * upgrade the siblings to singleton events by adding them
2002 * to whatever list we are on.
2004 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, sibling_list
) {
2006 sibling
->group_leader
= sibling
;
2007 list_del_init(&sibling
->sibling_list
);
2009 /* Inherit group flags from the previous leader */
2010 sibling
->group_caps
= event
->group_caps
;
2012 if (!RB_EMPTY_NODE(&event
->group_node
)) {
2013 add_event_to_groups(sibling
, event
->ctx
);
2015 if (sibling
->state
== PERF_EVENT_STATE_ACTIVE
) {
2016 struct list_head
*list
= sibling
->attr
.pinned
?
2017 &ctx
->pinned_active
: &ctx
->flexible_active
;
2019 list_add_tail(&sibling
->active_list
, list
);
2023 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
2027 perf_event__header_size(event
->group_leader
);
2029 for_each_sibling_event(tmp
, event
->group_leader
)
2030 perf_event__header_size(tmp
);
2033 static bool is_orphaned_event(struct perf_event
*event
)
2035 return event
->state
== PERF_EVENT_STATE_DEAD
;
2038 static inline int __pmu_filter_match(struct perf_event
*event
)
2040 struct pmu
*pmu
= event
->pmu
;
2041 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
2045 * Check whether we should attempt to schedule an event group based on
2046 * PMU-specific filtering. An event group can consist of HW and SW events,
2047 * potentially with a SW leader, so we must check all the filters, to
2048 * determine whether a group is schedulable:
2050 static inline int pmu_filter_match(struct perf_event
*event
)
2052 struct perf_event
*sibling
;
2054 if (!__pmu_filter_match(event
))
2057 for_each_sibling_event(sibling
, event
) {
2058 if (!__pmu_filter_match(sibling
))
2066 event_filter_match(struct perf_event
*event
)
2068 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
2069 perf_cgroup_match(event
) && pmu_filter_match(event
);
2073 event_sched_out(struct perf_event
*event
,
2074 struct perf_cpu_context
*cpuctx
,
2075 struct perf_event_context
*ctx
)
2077 enum perf_event_state state
= PERF_EVENT_STATE_INACTIVE
;
2079 WARN_ON_ONCE(event
->ctx
!= ctx
);
2080 lockdep_assert_held(&ctx
->lock
);
2082 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2086 * Asymmetry; we only schedule events _IN_ through ctx_sched_in(), but
2087 * we can schedule events _OUT_ individually through things like
2088 * __perf_remove_from_context().
2090 list_del_init(&event
->active_list
);
2092 perf_pmu_disable(event
->pmu
);
2094 event
->pmu
->del(event
, 0);
2097 if (READ_ONCE(event
->pending_disable
) >= 0) {
2098 WRITE_ONCE(event
->pending_disable
, -1);
2099 state
= PERF_EVENT_STATE_OFF
;
2101 perf_event_set_state(event
, state
);
2103 if (!is_software_event(event
))
2104 cpuctx
->active_oncpu
--;
2105 if (!--ctx
->nr_active
)
2106 perf_event_ctx_deactivate(ctx
);
2107 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2109 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
2110 cpuctx
->exclusive
= 0;
2112 perf_pmu_enable(event
->pmu
);
2116 group_sched_out(struct perf_event
*group_event
,
2117 struct perf_cpu_context
*cpuctx
,
2118 struct perf_event_context
*ctx
)
2120 struct perf_event
*event
;
2122 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2125 perf_pmu_disable(ctx
->pmu
);
2127 event_sched_out(group_event
, cpuctx
, ctx
);
2130 * Schedule out siblings (if any):
2132 for_each_sibling_event(event
, group_event
)
2133 event_sched_out(event
, cpuctx
, ctx
);
2135 perf_pmu_enable(ctx
->pmu
);
2137 if (group_event
->attr
.exclusive
)
2138 cpuctx
->exclusive
= 0;
2141 #define DETACH_GROUP 0x01UL
2144 * Cross CPU call to remove a performance event
2146 * We disable the event on the hardware level first. After that we
2147 * remove it from the context list.
2150 __perf_remove_from_context(struct perf_event
*event
,
2151 struct perf_cpu_context
*cpuctx
,
2152 struct perf_event_context
*ctx
,
2155 unsigned long flags
= (unsigned long)info
;
2157 if (ctx
->is_active
& EVENT_TIME
) {
2158 update_context_time(ctx
);
2159 update_cgrp_time_from_cpuctx(cpuctx
);
2162 event_sched_out(event
, cpuctx
, ctx
);
2163 if (flags
& DETACH_GROUP
)
2164 perf_group_detach(event
);
2165 list_del_event(event
, ctx
);
2167 if (!ctx
->nr_events
&& ctx
->is_active
) {
2170 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2171 cpuctx
->task_ctx
= NULL
;
2177 * Remove the event from a task's (or a CPU's) list of events.
2179 * If event->ctx is a cloned context, callers must make sure that
2180 * every task struct that event->ctx->task could possibly point to
2181 * remains valid. This is OK when called from perf_release since
2182 * that only calls us on the top-level context, which can't be a clone.
2183 * When called from perf_event_exit_task, it's OK because the
2184 * context has been detached from its task.
2186 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
2188 struct perf_event_context
*ctx
= event
->ctx
;
2190 lockdep_assert_held(&ctx
->mutex
);
2192 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
2195 * The above event_function_call() can NO-OP when it hits
2196 * TASK_TOMBSTONE. In that case we must already have been detached
2197 * from the context (by perf_event_exit_event()) but the grouping
2198 * might still be in-tact.
2200 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
2201 if ((flags
& DETACH_GROUP
) &&
2202 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
2204 * Since in that case we cannot possibly be scheduled, simply
2207 raw_spin_lock_irq(&ctx
->lock
);
2208 perf_group_detach(event
);
2209 raw_spin_unlock_irq(&ctx
->lock
);
2214 * Cross CPU call to disable a performance event
2216 static void __perf_event_disable(struct perf_event
*event
,
2217 struct perf_cpu_context
*cpuctx
,
2218 struct perf_event_context
*ctx
,
2221 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
2224 if (ctx
->is_active
& EVENT_TIME
) {
2225 update_context_time(ctx
);
2226 update_cgrp_time_from_event(event
);
2229 if (event
== event
->group_leader
)
2230 group_sched_out(event
, cpuctx
, ctx
);
2232 event_sched_out(event
, cpuctx
, ctx
);
2234 perf_event_set_state(event
, PERF_EVENT_STATE_OFF
);
2240 * If event->ctx is a cloned context, callers must make sure that
2241 * every task struct that event->ctx->task could possibly point to
2242 * remains valid. This condition is satisfied when called through
2243 * perf_event_for_each_child or perf_event_for_each because they
2244 * hold the top-level event's child_mutex, so any descendant that
2245 * goes to exit will block in perf_event_exit_event().
2247 * When called from perf_pending_event it's OK because event->ctx
2248 * is the current context on this CPU and preemption is disabled,
2249 * hence we can't get into perf_event_task_sched_out for this context.
2251 static void _perf_event_disable(struct perf_event
*event
)
2253 struct perf_event_context
*ctx
= event
->ctx
;
2255 raw_spin_lock_irq(&ctx
->lock
);
2256 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2257 raw_spin_unlock_irq(&ctx
->lock
);
2260 raw_spin_unlock_irq(&ctx
->lock
);
2262 event_function_call(event
, __perf_event_disable
, NULL
);
2265 void perf_event_disable_local(struct perf_event
*event
)
2267 event_function_local(event
, __perf_event_disable
, NULL
);
2271 * Strictly speaking kernel users cannot create groups and therefore this
2272 * interface does not need the perf_event_ctx_lock() magic.
2274 void perf_event_disable(struct perf_event
*event
)
2276 struct perf_event_context
*ctx
;
2278 ctx
= perf_event_ctx_lock(event
);
2279 _perf_event_disable(event
);
2280 perf_event_ctx_unlock(event
, ctx
);
2282 EXPORT_SYMBOL_GPL(perf_event_disable
);
2284 void perf_event_disable_inatomic(struct perf_event
*event
)
2286 WRITE_ONCE(event
->pending_disable
, smp_processor_id());
2287 /* can fail, see perf_pending_event_disable() */
2288 irq_work_queue(&event
->pending
);
2291 static void perf_set_shadow_time(struct perf_event
*event
,
2292 struct perf_event_context
*ctx
)
2295 * use the correct time source for the time snapshot
2297 * We could get by without this by leveraging the
2298 * fact that to get to this function, the caller
2299 * has most likely already called update_context_time()
2300 * and update_cgrp_time_xx() and thus both timestamp
2301 * are identical (or very close). Given that tstamp is,
2302 * already adjusted for cgroup, we could say that:
2303 * tstamp - ctx->timestamp
2305 * tstamp - cgrp->timestamp.
2307 * Then, in perf_output_read(), the calculation would
2308 * work with no changes because:
2309 * - event is guaranteed scheduled in
2310 * - no scheduled out in between
2311 * - thus the timestamp would be the same
2313 * But this is a bit hairy.
2315 * So instead, we have an explicit cgroup call to remain
2316 * within the time time source all along. We believe it
2317 * is cleaner and simpler to understand.
2319 if (is_cgroup_event(event
))
2320 perf_cgroup_set_shadow_time(event
, event
->tstamp
);
2322 event
->shadow_ctx_time
= event
->tstamp
- ctx
->timestamp
;
2325 #define MAX_INTERRUPTS (~0ULL)
2327 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2328 static void perf_log_itrace_start(struct perf_event
*event
);
2331 event_sched_in(struct perf_event
*event
,
2332 struct perf_cpu_context
*cpuctx
,
2333 struct perf_event_context
*ctx
)
2337 lockdep_assert_held(&ctx
->lock
);
2339 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2342 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2344 * Order event::oncpu write to happen before the ACTIVE state is
2345 * visible. This allows perf_event_{stop,read}() to observe the correct
2346 * ->oncpu if it sees ACTIVE.
2349 perf_event_set_state(event
, PERF_EVENT_STATE_ACTIVE
);
2352 * Unthrottle events, since we scheduled we might have missed several
2353 * ticks already, also for a heavily scheduling task there is little
2354 * guarantee it'll get a tick in a timely manner.
2356 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2357 perf_log_throttle(event
, 1);
2358 event
->hw
.interrupts
= 0;
2361 perf_pmu_disable(event
->pmu
);
2363 perf_set_shadow_time(event
, ctx
);
2365 perf_log_itrace_start(event
);
2367 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2368 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2374 if (!is_software_event(event
))
2375 cpuctx
->active_oncpu
++;
2376 if (!ctx
->nr_active
++)
2377 perf_event_ctx_activate(ctx
);
2378 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2381 if (event
->attr
.exclusive
)
2382 cpuctx
->exclusive
= 1;
2385 perf_pmu_enable(event
->pmu
);
2391 group_sched_in(struct perf_event
*group_event
,
2392 struct perf_cpu_context
*cpuctx
,
2393 struct perf_event_context
*ctx
)
2395 struct perf_event
*event
, *partial_group
= NULL
;
2396 struct pmu
*pmu
= ctx
->pmu
;
2398 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2401 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2403 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2404 pmu
->cancel_txn(pmu
);
2405 perf_mux_hrtimer_restart(cpuctx
);
2410 * Schedule in siblings as one group (if any):
2412 for_each_sibling_event(event
, group_event
) {
2413 if (event_sched_in(event
, cpuctx
, ctx
)) {
2414 partial_group
= event
;
2419 if (!pmu
->commit_txn(pmu
))
2424 * Groups can be scheduled in as one unit only, so undo any
2425 * partial group before returning:
2426 * The events up to the failed event are scheduled out normally.
2428 for_each_sibling_event(event
, group_event
) {
2429 if (event
== partial_group
)
2432 event_sched_out(event
, cpuctx
, ctx
);
2434 event_sched_out(group_event
, cpuctx
, ctx
);
2436 pmu
->cancel_txn(pmu
);
2438 perf_mux_hrtimer_restart(cpuctx
);
2444 * Work out whether we can put this event group on the CPU now.
2446 static int group_can_go_on(struct perf_event
*event
,
2447 struct perf_cpu_context
*cpuctx
,
2451 * Groups consisting entirely of software events can always go on.
2453 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2456 * If an exclusive group is already on, no other hardware
2459 if (cpuctx
->exclusive
)
2462 * If this group is exclusive and there are already
2463 * events on the CPU, it can't go on.
2465 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2468 * Otherwise, try to add it if all previous groups were able
2474 static void add_event_to_ctx(struct perf_event
*event
,
2475 struct perf_event_context
*ctx
)
2477 list_add_event(event
, ctx
);
2478 perf_group_attach(event
);
2481 static void ctx_sched_out(struct perf_event_context
*ctx
,
2482 struct perf_cpu_context
*cpuctx
,
2483 enum event_type_t event_type
);
2485 ctx_sched_in(struct perf_event_context
*ctx
,
2486 struct perf_cpu_context
*cpuctx
,
2487 enum event_type_t event_type
,
2488 struct task_struct
*task
);
2490 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2491 struct perf_event_context
*ctx
,
2492 enum event_type_t event_type
)
2494 if (!cpuctx
->task_ctx
)
2497 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2500 ctx_sched_out(ctx
, cpuctx
, event_type
);
2503 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2504 struct perf_event_context
*ctx
,
2505 struct task_struct
*task
)
2507 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2509 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2510 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2512 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2516 * We want to maintain the following priority of scheduling:
2517 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2518 * - task pinned (EVENT_PINNED)
2519 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2520 * - task flexible (EVENT_FLEXIBLE).
2522 * In order to avoid unscheduling and scheduling back in everything every
2523 * time an event is added, only do it for the groups of equal priority and
2526 * This can be called after a batch operation on task events, in which case
2527 * event_type is a bit mask of the types of events involved. For CPU events,
2528 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2530 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2531 struct perf_event_context
*task_ctx
,
2532 enum event_type_t event_type
)
2534 enum event_type_t ctx_event_type
;
2535 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2538 * If pinned groups are involved, flexible groups also need to be
2541 if (event_type
& EVENT_PINNED
)
2542 event_type
|= EVENT_FLEXIBLE
;
2544 ctx_event_type
= event_type
& EVENT_ALL
;
2546 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2548 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2551 * Decide which cpu ctx groups to schedule out based on the types
2552 * of events that caused rescheduling:
2553 * - EVENT_CPU: schedule out corresponding groups;
2554 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2555 * - otherwise, do nothing more.
2558 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2559 else if (ctx_event_type
& EVENT_PINNED
)
2560 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2562 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2563 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2566 void perf_pmu_resched(struct pmu
*pmu
)
2568 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2569 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2571 perf_ctx_lock(cpuctx
, task_ctx
);
2572 ctx_resched(cpuctx
, task_ctx
, EVENT_ALL
|EVENT_CPU
);
2573 perf_ctx_unlock(cpuctx
, task_ctx
);
2577 * Cross CPU call to install and enable a performance event
2579 * Very similar to remote_function() + event_function() but cannot assume that
2580 * things like ctx->is_active and cpuctx->task_ctx are set.
2582 static int __perf_install_in_context(void *info
)
2584 struct perf_event
*event
= info
;
2585 struct perf_event_context
*ctx
= event
->ctx
;
2586 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2587 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2588 bool reprogram
= true;
2591 raw_spin_lock(&cpuctx
->ctx
.lock
);
2593 raw_spin_lock(&ctx
->lock
);
2596 reprogram
= (ctx
->task
== current
);
2599 * If the task is running, it must be running on this CPU,
2600 * otherwise we cannot reprogram things.
2602 * If its not running, we don't care, ctx->lock will
2603 * serialize against it becoming runnable.
2605 if (task_curr(ctx
->task
) && !reprogram
) {
2610 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2611 } else if (task_ctx
) {
2612 raw_spin_lock(&task_ctx
->lock
);
2615 #ifdef CONFIG_CGROUP_PERF
2616 if (is_cgroup_event(event
)) {
2618 * If the current cgroup doesn't match the event's
2619 * cgroup, we should not try to schedule it.
2621 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2622 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2623 event
->cgrp
->css
.cgroup
);
2628 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2629 add_event_to_ctx(event
, ctx
);
2630 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2632 add_event_to_ctx(event
, ctx
);
2636 perf_ctx_unlock(cpuctx
, task_ctx
);
2641 static bool exclusive_event_installable(struct perf_event
*event
,
2642 struct perf_event_context
*ctx
);
2645 * Attach a performance event to a context.
2647 * Very similar to event_function_call, see comment there.
2650 perf_install_in_context(struct perf_event_context
*ctx
,
2651 struct perf_event
*event
,
2654 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2656 lockdep_assert_held(&ctx
->mutex
);
2658 WARN_ON_ONCE(!exclusive_event_installable(event
, ctx
));
2660 if (event
->cpu
!= -1)
2664 * Ensures that if we can observe event->ctx, both the event and ctx
2665 * will be 'complete'. See perf_iterate_sb_cpu().
2667 smp_store_release(&event
->ctx
, ctx
);
2670 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2675 * Should not happen, we validate the ctx is still alive before calling.
2677 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2681 * Installing events is tricky because we cannot rely on ctx->is_active
2682 * to be set in case this is the nr_events 0 -> 1 transition.
2684 * Instead we use task_curr(), which tells us if the task is running.
2685 * However, since we use task_curr() outside of rq::lock, we can race
2686 * against the actual state. This means the result can be wrong.
2688 * If we get a false positive, we retry, this is harmless.
2690 * If we get a false negative, things are complicated. If we are after
2691 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2692 * value must be correct. If we're before, it doesn't matter since
2693 * perf_event_context_sched_in() will program the counter.
2695 * However, this hinges on the remote context switch having observed
2696 * our task->perf_event_ctxp[] store, such that it will in fact take
2697 * ctx::lock in perf_event_context_sched_in().
2699 * We do this by task_function_call(), if the IPI fails to hit the task
2700 * we know any future context switch of task must see the
2701 * perf_event_ctpx[] store.
2705 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2706 * task_cpu() load, such that if the IPI then does not find the task
2707 * running, a future context switch of that task must observe the
2712 if (!task_function_call(task
, __perf_install_in_context
, event
))
2715 raw_spin_lock_irq(&ctx
->lock
);
2717 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2719 * Cannot happen because we already checked above (which also
2720 * cannot happen), and we hold ctx->mutex, which serializes us
2721 * against perf_event_exit_task_context().
2723 raw_spin_unlock_irq(&ctx
->lock
);
2727 * If the task is not running, ctx->lock will avoid it becoming so,
2728 * thus we can safely install the event.
2730 if (task_curr(task
)) {
2731 raw_spin_unlock_irq(&ctx
->lock
);
2734 add_event_to_ctx(event
, ctx
);
2735 raw_spin_unlock_irq(&ctx
->lock
);
2739 * Cross CPU call to enable a performance event
2741 static void __perf_event_enable(struct perf_event
*event
,
2742 struct perf_cpu_context
*cpuctx
,
2743 struct perf_event_context
*ctx
,
2746 struct perf_event
*leader
= event
->group_leader
;
2747 struct perf_event_context
*task_ctx
;
2749 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2750 event
->state
<= PERF_EVENT_STATE_ERROR
)
2754 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2756 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
2758 if (!ctx
->is_active
)
2761 if (!event_filter_match(event
)) {
2762 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2767 * If the event is in a group and isn't the group leader,
2768 * then don't put it on unless the group is on.
2770 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2771 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2775 task_ctx
= cpuctx
->task_ctx
;
2777 WARN_ON_ONCE(task_ctx
!= ctx
);
2779 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2785 * If event->ctx is a cloned context, callers must make sure that
2786 * every task struct that event->ctx->task could possibly point to
2787 * remains valid. This condition is satisfied when called through
2788 * perf_event_for_each_child or perf_event_for_each as described
2789 * for perf_event_disable.
2791 static void _perf_event_enable(struct perf_event
*event
)
2793 struct perf_event_context
*ctx
= event
->ctx
;
2795 raw_spin_lock_irq(&ctx
->lock
);
2796 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2797 event
->state
< PERF_EVENT_STATE_ERROR
) {
2798 raw_spin_unlock_irq(&ctx
->lock
);
2803 * If the event is in error state, clear that first.
2805 * That way, if we see the event in error state below, we know that it
2806 * has gone back into error state, as distinct from the task having
2807 * been scheduled away before the cross-call arrived.
2809 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2810 event
->state
= PERF_EVENT_STATE_OFF
;
2811 raw_spin_unlock_irq(&ctx
->lock
);
2813 event_function_call(event
, __perf_event_enable
, NULL
);
2817 * See perf_event_disable();
2819 void perf_event_enable(struct perf_event
*event
)
2821 struct perf_event_context
*ctx
;
2823 ctx
= perf_event_ctx_lock(event
);
2824 _perf_event_enable(event
);
2825 perf_event_ctx_unlock(event
, ctx
);
2827 EXPORT_SYMBOL_GPL(perf_event_enable
);
2829 struct stop_event_data
{
2830 struct perf_event
*event
;
2831 unsigned int restart
;
2834 static int __perf_event_stop(void *info
)
2836 struct stop_event_data
*sd
= info
;
2837 struct perf_event
*event
= sd
->event
;
2839 /* if it's already INACTIVE, do nothing */
2840 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2843 /* matches smp_wmb() in event_sched_in() */
2847 * There is a window with interrupts enabled before we get here,
2848 * so we need to check again lest we try to stop another CPU's event.
2850 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2853 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2856 * May race with the actual stop (through perf_pmu_output_stop()),
2857 * but it is only used for events with AUX ring buffer, and such
2858 * events will refuse to restart because of rb::aux_mmap_count==0,
2859 * see comments in perf_aux_output_begin().
2861 * Since this is happening on an event-local CPU, no trace is lost
2865 event
->pmu
->start(event
, 0);
2870 static int perf_event_stop(struct perf_event
*event
, int restart
)
2872 struct stop_event_data sd
= {
2879 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2882 /* matches smp_wmb() in event_sched_in() */
2886 * We only want to restart ACTIVE events, so if the event goes
2887 * inactive here (event->oncpu==-1), there's nothing more to do;
2888 * fall through with ret==-ENXIO.
2890 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2891 __perf_event_stop
, &sd
);
2892 } while (ret
== -EAGAIN
);
2898 * In order to contain the amount of racy and tricky in the address filter
2899 * configuration management, it is a two part process:
2901 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2902 * we update the addresses of corresponding vmas in
2903 * event::addr_filter_ranges array and bump the event::addr_filters_gen;
2904 * (p2) when an event is scheduled in (pmu::add), it calls
2905 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2906 * if the generation has changed since the previous call.
2908 * If (p1) happens while the event is active, we restart it to force (p2).
2910 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2911 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2913 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2914 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2916 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2919 void perf_event_addr_filters_sync(struct perf_event
*event
)
2921 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2923 if (!has_addr_filter(event
))
2926 raw_spin_lock(&ifh
->lock
);
2927 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2928 event
->pmu
->addr_filters_sync(event
);
2929 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2931 raw_spin_unlock(&ifh
->lock
);
2933 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2935 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2938 * not supported on inherited events
2940 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2943 atomic_add(refresh
, &event
->event_limit
);
2944 _perf_event_enable(event
);
2950 * See perf_event_disable()
2952 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2954 struct perf_event_context
*ctx
;
2957 ctx
= perf_event_ctx_lock(event
);
2958 ret
= _perf_event_refresh(event
, refresh
);
2959 perf_event_ctx_unlock(event
, ctx
);
2963 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2965 static int perf_event_modify_breakpoint(struct perf_event
*bp
,
2966 struct perf_event_attr
*attr
)
2970 _perf_event_disable(bp
);
2972 err
= modify_user_hw_breakpoint_check(bp
, attr
, true);
2974 if (!bp
->attr
.disabled
)
2975 _perf_event_enable(bp
);
2980 static int perf_event_modify_attr(struct perf_event
*event
,
2981 struct perf_event_attr
*attr
)
2983 if (event
->attr
.type
!= attr
->type
)
2986 switch (event
->attr
.type
) {
2987 case PERF_TYPE_BREAKPOINT
:
2988 return perf_event_modify_breakpoint(event
, attr
);
2990 /* Place holder for future additions. */
2995 static void ctx_sched_out(struct perf_event_context
*ctx
,
2996 struct perf_cpu_context
*cpuctx
,
2997 enum event_type_t event_type
)
2999 struct perf_event
*event
, *tmp
;
3000 int is_active
= ctx
->is_active
;
3002 lockdep_assert_held(&ctx
->lock
);
3004 if (likely(!ctx
->nr_events
)) {
3006 * See __perf_remove_from_context().
3008 WARN_ON_ONCE(ctx
->is_active
);
3010 WARN_ON_ONCE(cpuctx
->task_ctx
);
3014 ctx
->is_active
&= ~event_type
;
3015 if (!(ctx
->is_active
& EVENT_ALL
))
3019 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3020 if (!ctx
->is_active
)
3021 cpuctx
->task_ctx
= NULL
;
3025 * Always update time if it was set; not only when it changes.
3026 * Otherwise we can 'forget' to update time for any but the last
3027 * context we sched out. For example:
3029 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
3030 * ctx_sched_out(.event_type = EVENT_PINNED)
3032 * would only update time for the pinned events.
3034 if (is_active
& EVENT_TIME
) {
3035 /* update (and stop) ctx time */
3036 update_context_time(ctx
);
3037 update_cgrp_time_from_cpuctx(cpuctx
);
3040 is_active
^= ctx
->is_active
; /* changed bits */
3042 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
3046 * If we had been multiplexing, no rotations are necessary, now no events
3049 ctx
->rotate_necessary
= 0;
3051 perf_pmu_disable(ctx
->pmu
);
3052 if (is_active
& EVENT_PINNED
) {
3053 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_active
, active_list
)
3054 group_sched_out(event
, cpuctx
, ctx
);
3057 if (is_active
& EVENT_FLEXIBLE
) {
3058 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_active
, active_list
)
3059 group_sched_out(event
, cpuctx
, ctx
);
3061 perf_pmu_enable(ctx
->pmu
);
3065 * Test whether two contexts are equivalent, i.e. whether they have both been
3066 * cloned from the same version of the same context.
3068 * Equivalence is measured using a generation number in the context that is
3069 * incremented on each modification to it; see unclone_ctx(), list_add_event()
3070 * and list_del_event().
3072 static int context_equiv(struct perf_event_context
*ctx1
,
3073 struct perf_event_context
*ctx2
)
3075 lockdep_assert_held(&ctx1
->lock
);
3076 lockdep_assert_held(&ctx2
->lock
);
3078 /* Pinning disables the swap optimization */
3079 if (ctx1
->pin_count
|| ctx2
->pin_count
)
3082 /* If ctx1 is the parent of ctx2 */
3083 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
3086 /* If ctx2 is the parent of ctx1 */
3087 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
3091 * If ctx1 and ctx2 have the same parent; we flatten the parent
3092 * hierarchy, see perf_event_init_context().
3094 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
3095 ctx1
->parent_gen
== ctx2
->parent_gen
)
3102 static void __perf_event_sync_stat(struct perf_event
*event
,
3103 struct perf_event
*next_event
)
3107 if (!event
->attr
.inherit_stat
)
3111 * Update the event value, we cannot use perf_event_read()
3112 * because we're in the middle of a context switch and have IRQs
3113 * disabled, which upsets smp_call_function_single(), however
3114 * we know the event must be on the current CPU, therefore we
3115 * don't need to use it.
3117 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3118 event
->pmu
->read(event
);
3120 perf_event_update_time(event
);
3123 * In order to keep per-task stats reliable we need to flip the event
3124 * values when we flip the contexts.
3126 value
= local64_read(&next_event
->count
);
3127 value
= local64_xchg(&event
->count
, value
);
3128 local64_set(&next_event
->count
, value
);
3130 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
3131 swap(event
->total_time_running
, next_event
->total_time_running
);
3134 * Since we swizzled the values, update the user visible data too.
3136 perf_event_update_userpage(event
);
3137 perf_event_update_userpage(next_event
);
3140 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
3141 struct perf_event_context
*next_ctx
)
3143 struct perf_event
*event
, *next_event
;
3148 update_context_time(ctx
);
3150 event
= list_first_entry(&ctx
->event_list
,
3151 struct perf_event
, event_entry
);
3153 next_event
= list_first_entry(&next_ctx
->event_list
,
3154 struct perf_event
, event_entry
);
3156 while (&event
->event_entry
!= &ctx
->event_list
&&
3157 &next_event
->event_entry
!= &next_ctx
->event_list
) {
3159 __perf_event_sync_stat(event
, next_event
);
3161 event
= list_next_entry(event
, event_entry
);
3162 next_event
= list_next_entry(next_event
, event_entry
);
3166 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
3167 struct task_struct
*next
)
3169 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
3170 struct perf_event_context
*next_ctx
;
3171 struct perf_event_context
*parent
, *next_parent
;
3172 struct perf_cpu_context
*cpuctx
;
3178 cpuctx
= __get_cpu_context(ctx
);
3179 if (!cpuctx
->task_ctx
)
3183 next_ctx
= next
->perf_event_ctxp
[ctxn
];
3187 parent
= rcu_dereference(ctx
->parent_ctx
);
3188 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
3190 /* If neither context have a parent context; they cannot be clones. */
3191 if (!parent
&& !next_parent
)
3194 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
3196 * Looks like the two contexts are clones, so we might be
3197 * able to optimize the context switch. We lock both
3198 * contexts and check that they are clones under the
3199 * lock (including re-checking that neither has been
3200 * uncloned in the meantime). It doesn't matter which
3201 * order we take the locks because no other cpu could
3202 * be trying to lock both of these tasks.
3204 raw_spin_lock(&ctx
->lock
);
3205 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
3206 if (context_equiv(ctx
, next_ctx
)) {
3207 WRITE_ONCE(ctx
->task
, next
);
3208 WRITE_ONCE(next_ctx
->task
, task
);
3210 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
3213 * RCU_INIT_POINTER here is safe because we've not
3214 * modified the ctx and the above modification of
3215 * ctx->task and ctx->task_ctx_data are immaterial
3216 * since those values are always verified under
3217 * ctx->lock which we're now holding.
3219 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
3220 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
3224 perf_event_sync_stat(ctx
, next_ctx
);
3226 raw_spin_unlock(&next_ctx
->lock
);
3227 raw_spin_unlock(&ctx
->lock
);
3233 raw_spin_lock(&ctx
->lock
);
3234 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
3235 raw_spin_unlock(&ctx
->lock
);
3239 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
3241 void perf_sched_cb_dec(struct pmu
*pmu
)
3243 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3245 this_cpu_dec(perf_sched_cb_usages
);
3247 if (!--cpuctx
->sched_cb_usage
)
3248 list_del(&cpuctx
->sched_cb_entry
);
3252 void perf_sched_cb_inc(struct pmu
*pmu
)
3254 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3256 if (!cpuctx
->sched_cb_usage
++)
3257 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3259 this_cpu_inc(perf_sched_cb_usages
);
3263 * This function provides the context switch callback to the lower code
3264 * layer. It is invoked ONLY when the context switch callback is enabled.
3266 * This callback is relevant even to per-cpu events; for example multi event
3267 * PEBS requires this to provide PID/TID information. This requires we flush
3268 * all queued PEBS records before we context switch to a new task.
3270 static void perf_pmu_sched_task(struct task_struct
*prev
,
3271 struct task_struct
*next
,
3274 struct perf_cpu_context
*cpuctx
;
3280 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3281 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3283 if (WARN_ON_ONCE(!pmu
->sched_task
))
3286 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3287 perf_pmu_disable(pmu
);
3289 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3291 perf_pmu_enable(pmu
);
3292 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3296 static void perf_event_switch(struct task_struct
*task
,
3297 struct task_struct
*next_prev
, bool sched_in
);
3299 #define for_each_task_context_nr(ctxn) \
3300 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3303 * Called from scheduler to remove the events of the current task,
3304 * with interrupts disabled.
3306 * We stop each event and update the event value in event->count.
3308 * This does not protect us against NMI, but disable()
3309 * sets the disabled bit in the control field of event _before_
3310 * accessing the event control register. If a NMI hits, then it will
3311 * not restart the event.
3313 void __perf_event_task_sched_out(struct task_struct
*task
,
3314 struct task_struct
*next
)
3318 if (__this_cpu_read(perf_sched_cb_usages
))
3319 perf_pmu_sched_task(task
, next
, false);
3321 if (atomic_read(&nr_switch_events
))
3322 perf_event_switch(task
, next
, false);
3324 for_each_task_context_nr(ctxn
)
3325 perf_event_context_sched_out(task
, ctxn
, next
);
3328 * if cgroup events exist on this CPU, then we need
3329 * to check if we have to switch out PMU state.
3330 * cgroup event are system-wide mode only
3332 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3333 perf_cgroup_sched_out(task
, next
);
3337 * Called with IRQs disabled
3339 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3340 enum event_type_t event_type
)
3342 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3345 static int visit_groups_merge(struct perf_event_groups
*groups
, int cpu
,
3346 int (*func
)(struct perf_event
*, void *), void *data
)
3348 struct perf_event
**evt
, *evt1
, *evt2
;
3351 evt1
= perf_event_groups_first(groups
, -1);
3352 evt2
= perf_event_groups_first(groups
, cpu
);
3354 while (evt1
|| evt2
) {
3356 if (evt1
->group_index
< evt2
->group_index
)
3366 ret
= func(*evt
, data
);
3370 *evt
= perf_event_groups_next(*evt
);
3376 struct sched_in_data
{
3377 struct perf_event_context
*ctx
;
3378 struct perf_cpu_context
*cpuctx
;
3382 static int pinned_sched_in(struct perf_event
*event
, void *data
)
3384 struct sched_in_data
*sid
= data
;
3386 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3389 if (!event_filter_match(event
))
3392 if (group_can_go_on(event
, sid
->cpuctx
, sid
->can_add_hw
)) {
3393 if (!group_sched_in(event
, sid
->cpuctx
, sid
->ctx
))
3394 list_add_tail(&event
->active_list
, &sid
->ctx
->pinned_active
);
3398 * If this pinned group hasn't been scheduled,
3399 * put it in error state.
3401 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
3402 perf_event_set_state(event
, PERF_EVENT_STATE_ERROR
);
3407 static int flexible_sched_in(struct perf_event
*event
, void *data
)
3409 struct sched_in_data
*sid
= data
;
3411 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3414 if (!event_filter_match(event
))
3417 if (group_can_go_on(event
, sid
->cpuctx
, sid
->can_add_hw
)) {
3418 int ret
= group_sched_in(event
, sid
->cpuctx
, sid
->ctx
);
3420 sid
->can_add_hw
= 0;
3421 sid
->ctx
->rotate_necessary
= 1;
3424 list_add_tail(&event
->active_list
, &sid
->ctx
->flexible_active
);
3431 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3432 struct perf_cpu_context
*cpuctx
)
3434 struct sched_in_data sid
= {
3440 visit_groups_merge(&ctx
->pinned_groups
,
3442 pinned_sched_in
, &sid
);
3446 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3447 struct perf_cpu_context
*cpuctx
)
3449 struct sched_in_data sid
= {
3455 visit_groups_merge(&ctx
->flexible_groups
,
3457 flexible_sched_in
, &sid
);
3461 ctx_sched_in(struct perf_event_context
*ctx
,
3462 struct perf_cpu_context
*cpuctx
,
3463 enum event_type_t event_type
,
3464 struct task_struct
*task
)
3466 int is_active
= ctx
->is_active
;
3469 lockdep_assert_held(&ctx
->lock
);
3471 if (likely(!ctx
->nr_events
))
3474 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3477 cpuctx
->task_ctx
= ctx
;
3479 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3482 is_active
^= ctx
->is_active
; /* changed bits */
3484 if (is_active
& EVENT_TIME
) {
3485 /* start ctx time */
3487 ctx
->timestamp
= now
;
3488 perf_cgroup_set_timestamp(task
, ctx
);
3492 * First go through the list and put on any pinned groups
3493 * in order to give them the best chance of going on.
3495 if (is_active
& EVENT_PINNED
)
3496 ctx_pinned_sched_in(ctx
, cpuctx
);
3498 /* Then walk through the lower prio flexible groups */
3499 if (is_active
& EVENT_FLEXIBLE
)
3500 ctx_flexible_sched_in(ctx
, cpuctx
);
3503 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3504 enum event_type_t event_type
,
3505 struct task_struct
*task
)
3507 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3509 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3512 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3513 struct task_struct
*task
)
3515 struct perf_cpu_context
*cpuctx
;
3517 cpuctx
= __get_cpu_context(ctx
);
3518 if (cpuctx
->task_ctx
== ctx
)
3521 perf_ctx_lock(cpuctx
, ctx
);
3523 * We must check ctx->nr_events while holding ctx->lock, such
3524 * that we serialize against perf_install_in_context().
3526 if (!ctx
->nr_events
)
3529 perf_pmu_disable(ctx
->pmu
);
3531 * We want to keep the following priority order:
3532 * cpu pinned (that don't need to move), task pinned,
3533 * cpu flexible, task flexible.
3535 * However, if task's ctx is not carrying any pinned
3536 * events, no need to flip the cpuctx's events around.
3538 if (!RB_EMPTY_ROOT(&ctx
->pinned_groups
.tree
))
3539 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3540 perf_event_sched_in(cpuctx
, ctx
, task
);
3541 perf_pmu_enable(ctx
->pmu
);
3544 perf_ctx_unlock(cpuctx
, ctx
);
3548 * Called from scheduler to add the events of the current task
3549 * with interrupts disabled.
3551 * We restore the event value and then enable it.
3553 * This does not protect us against NMI, but enable()
3554 * sets the enabled bit in the control field of event _before_
3555 * accessing the event control register. If a NMI hits, then it will
3556 * keep the event running.
3558 void __perf_event_task_sched_in(struct task_struct
*prev
,
3559 struct task_struct
*task
)
3561 struct perf_event_context
*ctx
;
3565 * If cgroup events exist on this CPU, then we need to check if we have
3566 * to switch in PMU state; cgroup event are system-wide mode only.
3568 * Since cgroup events are CPU events, we must schedule these in before
3569 * we schedule in the task events.
3571 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3572 perf_cgroup_sched_in(prev
, task
);
3574 for_each_task_context_nr(ctxn
) {
3575 ctx
= task
->perf_event_ctxp
[ctxn
];
3579 perf_event_context_sched_in(ctx
, task
);
3582 if (atomic_read(&nr_switch_events
))
3583 perf_event_switch(task
, prev
, true);
3585 if (__this_cpu_read(perf_sched_cb_usages
))
3586 perf_pmu_sched_task(prev
, task
, true);
3589 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3591 u64 frequency
= event
->attr
.sample_freq
;
3592 u64 sec
= NSEC_PER_SEC
;
3593 u64 divisor
, dividend
;
3595 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3597 count_fls
= fls64(count
);
3598 nsec_fls
= fls64(nsec
);
3599 frequency_fls
= fls64(frequency
);
3603 * We got @count in @nsec, with a target of sample_freq HZ
3604 * the target period becomes:
3607 * period = -------------------
3608 * @nsec * sample_freq
3613 * Reduce accuracy by one bit such that @a and @b converge
3614 * to a similar magnitude.
3616 #define REDUCE_FLS(a, b) \
3618 if (a##_fls > b##_fls) { \
3628 * Reduce accuracy until either term fits in a u64, then proceed with
3629 * the other, so that finally we can do a u64/u64 division.
3631 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3632 REDUCE_FLS(nsec
, frequency
);
3633 REDUCE_FLS(sec
, count
);
3636 if (count_fls
+ sec_fls
> 64) {
3637 divisor
= nsec
* frequency
;
3639 while (count_fls
+ sec_fls
> 64) {
3640 REDUCE_FLS(count
, sec
);
3644 dividend
= count
* sec
;
3646 dividend
= count
* sec
;
3648 while (nsec_fls
+ frequency_fls
> 64) {
3649 REDUCE_FLS(nsec
, frequency
);
3653 divisor
= nsec
* frequency
;
3659 return div64_u64(dividend
, divisor
);
3662 static DEFINE_PER_CPU(int, perf_throttled_count
);
3663 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3665 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3667 struct hw_perf_event
*hwc
= &event
->hw
;
3668 s64 period
, sample_period
;
3671 period
= perf_calculate_period(event
, nsec
, count
);
3673 delta
= (s64
)(period
- hwc
->sample_period
);
3674 delta
= (delta
+ 7) / 8; /* low pass filter */
3676 sample_period
= hwc
->sample_period
+ delta
;
3681 hwc
->sample_period
= sample_period
;
3683 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3685 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3687 local64_set(&hwc
->period_left
, 0);
3690 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3695 * combine freq adjustment with unthrottling to avoid two passes over the
3696 * events. At the same time, make sure, having freq events does not change
3697 * the rate of unthrottling as that would introduce bias.
3699 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3702 struct perf_event
*event
;
3703 struct hw_perf_event
*hwc
;
3704 u64 now
, period
= TICK_NSEC
;
3708 * only need to iterate over all events iff:
3709 * - context have events in frequency mode (needs freq adjust)
3710 * - there are events to unthrottle on this cpu
3712 if (!(ctx
->nr_freq
|| needs_unthr
))
3715 raw_spin_lock(&ctx
->lock
);
3716 perf_pmu_disable(ctx
->pmu
);
3718 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3719 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3722 if (!event_filter_match(event
))
3725 perf_pmu_disable(event
->pmu
);
3729 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3730 hwc
->interrupts
= 0;
3731 perf_log_throttle(event
, 1);
3732 event
->pmu
->start(event
, 0);
3735 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3739 * stop the event and update event->count
3741 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3743 now
= local64_read(&event
->count
);
3744 delta
= now
- hwc
->freq_count_stamp
;
3745 hwc
->freq_count_stamp
= now
;
3749 * reload only if value has changed
3750 * we have stopped the event so tell that
3751 * to perf_adjust_period() to avoid stopping it
3755 perf_adjust_period(event
, period
, delta
, false);
3757 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3759 perf_pmu_enable(event
->pmu
);
3762 perf_pmu_enable(ctx
->pmu
);
3763 raw_spin_unlock(&ctx
->lock
);
3767 * Move @event to the tail of the @ctx's elegible events.
3769 static void rotate_ctx(struct perf_event_context
*ctx
, struct perf_event
*event
)
3772 * Rotate the first entry last of non-pinned groups. Rotation might be
3773 * disabled by the inheritance code.
3775 if (ctx
->rotate_disable
)
3778 perf_event_groups_delete(&ctx
->flexible_groups
, event
);
3779 perf_event_groups_insert(&ctx
->flexible_groups
, event
);
3782 /* pick an event from the flexible_groups to rotate */
3783 static inline struct perf_event
*
3784 ctx_event_to_rotate(struct perf_event_context
*ctx
)
3786 struct perf_event
*event
;
3788 /* pick the first active flexible event */
3789 event
= list_first_entry_or_null(&ctx
->flexible_active
,
3790 struct perf_event
, active_list
);
3792 /* if no active flexible event, pick the first event */
3794 event
= rb_entry_safe(rb_first(&ctx
->flexible_groups
.tree
),
3795 typeof(*event
), group_node
);
3801 static bool perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3803 struct perf_event
*cpu_event
= NULL
, *task_event
= NULL
;
3804 struct perf_event_context
*task_ctx
= NULL
;
3805 int cpu_rotate
, task_rotate
;
3808 * Since we run this from IRQ context, nobody can install new
3809 * events, thus the event count values are stable.
3812 cpu_rotate
= cpuctx
->ctx
.rotate_necessary
;
3813 task_ctx
= cpuctx
->task_ctx
;
3814 task_rotate
= task_ctx
? task_ctx
->rotate_necessary
: 0;
3816 if (!(cpu_rotate
|| task_rotate
))
3819 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3820 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3823 task_event
= ctx_event_to_rotate(task_ctx
);
3825 cpu_event
= ctx_event_to_rotate(&cpuctx
->ctx
);
3828 * As per the order given at ctx_resched() first 'pop' task flexible
3829 * and then, if needed CPU flexible.
3831 if (task_event
|| (task_ctx
&& cpu_event
))
3832 ctx_sched_out(task_ctx
, cpuctx
, EVENT_FLEXIBLE
);
3834 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3837 rotate_ctx(task_ctx
, task_event
);
3839 rotate_ctx(&cpuctx
->ctx
, cpu_event
);
3841 perf_event_sched_in(cpuctx
, task_ctx
, current
);
3843 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3844 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3849 void perf_event_task_tick(void)
3851 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3852 struct perf_event_context
*ctx
, *tmp
;
3855 lockdep_assert_irqs_disabled();
3857 __this_cpu_inc(perf_throttled_seq
);
3858 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3859 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3861 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3862 perf_adjust_freq_unthr_context(ctx
, throttled
);
3865 static int event_enable_on_exec(struct perf_event
*event
,
3866 struct perf_event_context
*ctx
)
3868 if (!event
->attr
.enable_on_exec
)
3871 event
->attr
.enable_on_exec
= 0;
3872 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3875 perf_event_set_state(event
, PERF_EVENT_STATE_INACTIVE
);
3881 * Enable all of a task's events that have been marked enable-on-exec.
3882 * This expects task == current.
3884 static void perf_event_enable_on_exec(int ctxn
)
3886 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3887 enum event_type_t event_type
= 0;
3888 struct perf_cpu_context
*cpuctx
;
3889 struct perf_event
*event
;
3890 unsigned long flags
;
3893 local_irq_save(flags
);
3894 ctx
= current
->perf_event_ctxp
[ctxn
];
3895 if (!ctx
|| !ctx
->nr_events
)
3898 cpuctx
= __get_cpu_context(ctx
);
3899 perf_ctx_lock(cpuctx
, ctx
);
3900 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3901 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3902 enabled
|= event_enable_on_exec(event
, ctx
);
3903 event_type
|= get_event_type(event
);
3907 * Unclone and reschedule this context if we enabled any event.
3910 clone_ctx
= unclone_ctx(ctx
);
3911 ctx_resched(cpuctx
, ctx
, event_type
);
3913 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3915 perf_ctx_unlock(cpuctx
, ctx
);
3918 local_irq_restore(flags
);
3924 struct perf_read_data
{
3925 struct perf_event
*event
;
3930 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3932 u16 local_pkg
, event_pkg
;
3934 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3935 int local_cpu
= smp_processor_id();
3937 event_pkg
= topology_physical_package_id(event_cpu
);
3938 local_pkg
= topology_physical_package_id(local_cpu
);
3940 if (event_pkg
== local_pkg
)
3948 * Cross CPU call to read the hardware event
3950 static void __perf_event_read(void *info
)
3952 struct perf_read_data
*data
= info
;
3953 struct perf_event
*sub
, *event
= data
->event
;
3954 struct perf_event_context
*ctx
= event
->ctx
;
3955 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3956 struct pmu
*pmu
= event
->pmu
;
3959 * If this is a task context, we need to check whether it is
3960 * the current task context of this cpu. If not it has been
3961 * scheduled out before the smp call arrived. In that case
3962 * event->count would have been updated to a recent sample
3963 * when the event was scheduled out.
3965 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3968 raw_spin_lock(&ctx
->lock
);
3969 if (ctx
->is_active
& EVENT_TIME
) {
3970 update_context_time(ctx
);
3971 update_cgrp_time_from_event(event
);
3974 perf_event_update_time(event
);
3976 perf_event_update_sibling_time(event
);
3978 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3987 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3991 for_each_sibling_event(sub
, event
) {
3992 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3994 * Use sibling's PMU rather than @event's since
3995 * sibling could be on different (eg: software) PMU.
3997 sub
->pmu
->read(sub
);
4001 data
->ret
= pmu
->commit_txn(pmu
);
4004 raw_spin_unlock(&ctx
->lock
);
4007 static inline u64
perf_event_count(struct perf_event
*event
)
4009 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
4013 * NMI-safe method to read a local event, that is an event that
4015 * - either for the current task, or for this CPU
4016 * - does not have inherit set, for inherited task events
4017 * will not be local and we cannot read them atomically
4018 * - must not have a pmu::count method
4020 int perf_event_read_local(struct perf_event
*event
, u64
*value
,
4021 u64
*enabled
, u64
*running
)
4023 unsigned long flags
;
4027 * Disabling interrupts avoids all counter scheduling (context
4028 * switches, timer based rotation and IPIs).
4030 local_irq_save(flags
);
4033 * It must not be an event with inherit set, we cannot read
4034 * all child counters from atomic context.
4036 if (event
->attr
.inherit
) {
4041 /* If this is a per-task event, it must be for current */
4042 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
4043 event
->hw
.target
!= current
) {
4048 /* If this is a per-CPU event, it must be for this CPU */
4049 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
4050 event
->cpu
!= smp_processor_id()) {
4055 /* If this is a pinned event it must be running on this CPU */
4056 if (event
->attr
.pinned
&& event
->oncpu
!= smp_processor_id()) {
4062 * If the event is currently on this CPU, its either a per-task event,
4063 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
4066 if (event
->oncpu
== smp_processor_id())
4067 event
->pmu
->read(event
);
4069 *value
= local64_read(&event
->count
);
4070 if (enabled
|| running
) {
4071 u64 now
= event
->shadow_ctx_time
+ perf_clock();
4072 u64 __enabled
, __running
;
4074 __perf_update_times(event
, now
, &__enabled
, &__running
);
4076 *enabled
= __enabled
;
4078 *running
= __running
;
4081 local_irq_restore(flags
);
4086 static int perf_event_read(struct perf_event
*event
, bool group
)
4088 enum perf_event_state state
= READ_ONCE(event
->state
);
4089 int event_cpu
, ret
= 0;
4092 * If event is enabled and currently active on a CPU, update the
4093 * value in the event structure:
4096 if (state
== PERF_EVENT_STATE_ACTIVE
) {
4097 struct perf_read_data data
;
4100 * Orders the ->state and ->oncpu loads such that if we see
4101 * ACTIVE we must also see the right ->oncpu.
4103 * Matches the smp_wmb() from event_sched_in().
4107 event_cpu
= READ_ONCE(event
->oncpu
);
4108 if ((unsigned)event_cpu
>= nr_cpu_ids
)
4111 data
= (struct perf_read_data
){
4118 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
4121 * Purposely ignore the smp_call_function_single() return
4124 * If event_cpu isn't a valid CPU it means the event got
4125 * scheduled out and that will have updated the event count.
4127 * Therefore, either way, we'll have an up-to-date event count
4130 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
4134 } else if (state
== PERF_EVENT_STATE_INACTIVE
) {
4135 struct perf_event_context
*ctx
= event
->ctx
;
4136 unsigned long flags
;
4138 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4139 state
= event
->state
;
4140 if (state
!= PERF_EVENT_STATE_INACTIVE
) {
4141 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4146 * May read while context is not active (e.g., thread is
4147 * blocked), in that case we cannot update context time
4149 if (ctx
->is_active
& EVENT_TIME
) {
4150 update_context_time(ctx
);
4151 update_cgrp_time_from_event(event
);
4154 perf_event_update_time(event
);
4156 perf_event_update_sibling_time(event
);
4157 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4164 * Initialize the perf_event context in a task_struct:
4166 static void __perf_event_init_context(struct perf_event_context
*ctx
)
4168 raw_spin_lock_init(&ctx
->lock
);
4169 mutex_init(&ctx
->mutex
);
4170 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
4171 perf_event_groups_init(&ctx
->pinned_groups
);
4172 perf_event_groups_init(&ctx
->flexible_groups
);
4173 INIT_LIST_HEAD(&ctx
->event_list
);
4174 INIT_LIST_HEAD(&ctx
->pinned_active
);
4175 INIT_LIST_HEAD(&ctx
->flexible_active
);
4176 refcount_set(&ctx
->refcount
, 1);
4179 static struct perf_event_context
*
4180 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
4182 struct perf_event_context
*ctx
;
4184 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
4188 __perf_event_init_context(ctx
);
4190 ctx
->task
= get_task_struct(task
);
4196 static struct task_struct
*
4197 find_lively_task_by_vpid(pid_t vpid
)
4199 struct task_struct
*task
;
4205 task
= find_task_by_vpid(vpid
);
4207 get_task_struct(task
);
4211 return ERR_PTR(-ESRCH
);
4217 * Returns a matching context with refcount and pincount.
4219 static struct perf_event_context
*
4220 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
4221 struct perf_event
*event
)
4223 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
4224 struct perf_cpu_context
*cpuctx
;
4225 void *task_ctx_data
= NULL
;
4226 unsigned long flags
;
4228 int cpu
= event
->cpu
;
4231 /* Must be root to operate on a CPU event: */
4232 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
4233 return ERR_PTR(-EACCES
);
4235 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
4244 ctxn
= pmu
->task_ctx_nr
;
4248 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
4249 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
4250 if (!task_ctx_data
) {
4257 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
4259 clone_ctx
= unclone_ctx(ctx
);
4262 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
4263 ctx
->task_ctx_data
= task_ctx_data
;
4264 task_ctx_data
= NULL
;
4266 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4271 ctx
= alloc_perf_context(pmu
, task
);
4276 if (task_ctx_data
) {
4277 ctx
->task_ctx_data
= task_ctx_data
;
4278 task_ctx_data
= NULL
;
4282 mutex_lock(&task
->perf_event_mutex
);
4284 * If it has already passed perf_event_exit_task().
4285 * we must see PF_EXITING, it takes this mutex too.
4287 if (task
->flags
& PF_EXITING
)
4289 else if (task
->perf_event_ctxp
[ctxn
])
4294 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
4296 mutex_unlock(&task
->perf_event_mutex
);
4298 if (unlikely(err
)) {
4307 kfree(task_ctx_data
);
4311 kfree(task_ctx_data
);
4312 return ERR_PTR(err
);
4315 static void perf_event_free_filter(struct perf_event
*event
);
4316 static void perf_event_free_bpf_prog(struct perf_event
*event
);
4318 static void free_event_rcu(struct rcu_head
*head
)
4320 struct perf_event
*event
;
4322 event
= container_of(head
, struct perf_event
, rcu_head
);
4324 put_pid_ns(event
->ns
);
4325 perf_event_free_filter(event
);
4329 static void ring_buffer_attach(struct perf_event
*event
,
4330 struct ring_buffer
*rb
);
4332 static void detach_sb_event(struct perf_event
*event
)
4334 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
4336 raw_spin_lock(&pel
->lock
);
4337 list_del_rcu(&event
->sb_list
);
4338 raw_spin_unlock(&pel
->lock
);
4341 static bool is_sb_event(struct perf_event
*event
)
4343 struct perf_event_attr
*attr
= &event
->attr
;
4348 if (event
->attach_state
& PERF_ATTACH_TASK
)
4351 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
4352 attr
->comm
|| attr
->comm_exec
||
4353 attr
->task
|| attr
->ksymbol
||
4354 attr
->context_switch
||
4360 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4362 if (is_sb_event(event
))
4363 detach_sb_event(event
);
4366 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4371 if (is_cgroup_event(event
))
4372 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4375 #ifdef CONFIG_NO_HZ_FULL
4376 static DEFINE_SPINLOCK(nr_freq_lock
);
4379 static void unaccount_freq_event_nohz(void)
4381 #ifdef CONFIG_NO_HZ_FULL
4382 spin_lock(&nr_freq_lock
);
4383 if (atomic_dec_and_test(&nr_freq_events
))
4384 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4385 spin_unlock(&nr_freq_lock
);
4389 static void unaccount_freq_event(void)
4391 if (tick_nohz_full_enabled())
4392 unaccount_freq_event_nohz();
4394 atomic_dec(&nr_freq_events
);
4397 static void unaccount_event(struct perf_event
*event
)
4404 if (event
->attach_state
& PERF_ATTACH_TASK
)
4406 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4407 atomic_dec(&nr_mmap_events
);
4408 if (event
->attr
.comm
)
4409 atomic_dec(&nr_comm_events
);
4410 if (event
->attr
.namespaces
)
4411 atomic_dec(&nr_namespaces_events
);
4412 if (event
->attr
.task
)
4413 atomic_dec(&nr_task_events
);
4414 if (event
->attr
.freq
)
4415 unaccount_freq_event();
4416 if (event
->attr
.context_switch
) {
4418 atomic_dec(&nr_switch_events
);
4420 if (is_cgroup_event(event
))
4422 if (has_branch_stack(event
))
4424 if (event
->attr
.ksymbol
)
4425 atomic_dec(&nr_ksymbol_events
);
4426 if (event
->attr
.bpf_event
)
4427 atomic_dec(&nr_bpf_events
);
4430 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4431 schedule_delayed_work(&perf_sched_work
, HZ
);
4434 unaccount_event_cpu(event
, event
->cpu
);
4436 unaccount_pmu_sb_event(event
);
4439 static void perf_sched_delayed(struct work_struct
*work
)
4441 mutex_lock(&perf_sched_mutex
);
4442 if (atomic_dec_and_test(&perf_sched_count
))
4443 static_branch_disable(&perf_sched_events
);
4444 mutex_unlock(&perf_sched_mutex
);
4448 * The following implement mutual exclusion of events on "exclusive" pmus
4449 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4450 * at a time, so we disallow creating events that might conflict, namely:
4452 * 1) cpu-wide events in the presence of per-task events,
4453 * 2) per-task events in the presence of cpu-wide events,
4454 * 3) two matching events on the same context.
4456 * The former two cases are handled in the allocation path (perf_event_alloc(),
4457 * _free_event()), the latter -- before the first perf_install_in_context().
4459 static int exclusive_event_init(struct perf_event
*event
)
4461 struct pmu
*pmu
= event
->pmu
;
4463 if (!is_exclusive_pmu(pmu
))
4467 * Prevent co-existence of per-task and cpu-wide events on the
4468 * same exclusive pmu.
4470 * Negative pmu::exclusive_cnt means there are cpu-wide
4471 * events on this "exclusive" pmu, positive means there are
4474 * Since this is called in perf_event_alloc() path, event::ctx
4475 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4476 * to mean "per-task event", because unlike other attach states it
4477 * never gets cleared.
4479 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4480 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4483 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4490 static void exclusive_event_destroy(struct perf_event
*event
)
4492 struct pmu
*pmu
= event
->pmu
;
4494 if (!is_exclusive_pmu(pmu
))
4497 /* see comment in exclusive_event_init() */
4498 if (event
->attach_state
& PERF_ATTACH_TASK
)
4499 atomic_dec(&pmu
->exclusive_cnt
);
4501 atomic_inc(&pmu
->exclusive_cnt
);
4504 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4506 if ((e1
->pmu
== e2
->pmu
) &&
4507 (e1
->cpu
== e2
->cpu
||
4514 static bool exclusive_event_installable(struct perf_event
*event
,
4515 struct perf_event_context
*ctx
)
4517 struct perf_event
*iter_event
;
4518 struct pmu
*pmu
= event
->pmu
;
4520 lockdep_assert_held(&ctx
->mutex
);
4522 if (!is_exclusive_pmu(pmu
))
4525 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4526 if (exclusive_event_match(iter_event
, event
))
4533 static void perf_addr_filters_splice(struct perf_event
*event
,
4534 struct list_head
*head
);
4536 static void _free_event(struct perf_event
*event
)
4538 irq_work_sync(&event
->pending
);
4540 unaccount_event(event
);
4544 * Can happen when we close an event with re-directed output.
4546 * Since we have a 0 refcount, perf_mmap_close() will skip
4547 * over us; possibly making our ring_buffer_put() the last.
4549 mutex_lock(&event
->mmap_mutex
);
4550 ring_buffer_attach(event
, NULL
);
4551 mutex_unlock(&event
->mmap_mutex
);
4554 if (is_cgroup_event(event
))
4555 perf_detach_cgroup(event
);
4557 if (!event
->parent
) {
4558 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4559 put_callchain_buffers();
4562 perf_event_free_bpf_prog(event
);
4563 perf_addr_filters_splice(event
, NULL
);
4564 kfree(event
->addr_filter_ranges
);
4567 event
->destroy(event
);
4570 * Must be after ->destroy(), due to uprobe_perf_close() using
4573 if (event
->hw
.target
)
4574 put_task_struct(event
->hw
.target
);
4577 * perf_event_free_task() relies on put_ctx() being 'last', in particular
4578 * all task references must be cleaned up.
4581 put_ctx(event
->ctx
);
4583 exclusive_event_destroy(event
);
4584 module_put(event
->pmu
->module
);
4586 call_rcu(&event
->rcu_head
, free_event_rcu
);
4590 * Used to free events which have a known refcount of 1, such as in error paths
4591 * where the event isn't exposed yet and inherited events.
4593 static void free_event(struct perf_event
*event
)
4595 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4596 "unexpected event refcount: %ld; ptr=%p\n",
4597 atomic_long_read(&event
->refcount
), event
)) {
4598 /* leak to avoid use-after-free */
4606 * Remove user event from the owner task.
4608 static void perf_remove_from_owner(struct perf_event
*event
)
4610 struct task_struct
*owner
;
4614 * Matches the smp_store_release() in perf_event_exit_task(). If we
4615 * observe !owner it means the list deletion is complete and we can
4616 * indeed free this event, otherwise we need to serialize on
4617 * owner->perf_event_mutex.
4619 owner
= READ_ONCE(event
->owner
);
4622 * Since delayed_put_task_struct() also drops the last
4623 * task reference we can safely take a new reference
4624 * while holding the rcu_read_lock().
4626 get_task_struct(owner
);
4632 * If we're here through perf_event_exit_task() we're already
4633 * holding ctx->mutex which would be an inversion wrt. the
4634 * normal lock order.
4636 * However we can safely take this lock because its the child
4639 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4642 * We have to re-check the event->owner field, if it is cleared
4643 * we raced with perf_event_exit_task(), acquiring the mutex
4644 * ensured they're done, and we can proceed with freeing the
4648 list_del_init(&event
->owner_entry
);
4649 smp_store_release(&event
->owner
, NULL
);
4651 mutex_unlock(&owner
->perf_event_mutex
);
4652 put_task_struct(owner
);
4656 static void put_event(struct perf_event
*event
)
4658 if (!atomic_long_dec_and_test(&event
->refcount
))
4665 * Kill an event dead; while event:refcount will preserve the event
4666 * object, it will not preserve its functionality. Once the last 'user'
4667 * gives up the object, we'll destroy the thing.
4669 int perf_event_release_kernel(struct perf_event
*event
)
4671 struct perf_event_context
*ctx
= event
->ctx
;
4672 struct perf_event
*child
, *tmp
;
4673 LIST_HEAD(free_list
);
4676 * If we got here through err_file: fput(event_file); we will not have
4677 * attached to a context yet.
4680 WARN_ON_ONCE(event
->attach_state
&
4681 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4685 if (!is_kernel_event(event
))
4686 perf_remove_from_owner(event
);
4688 ctx
= perf_event_ctx_lock(event
);
4689 WARN_ON_ONCE(ctx
->parent_ctx
);
4690 perf_remove_from_context(event
, DETACH_GROUP
);
4692 raw_spin_lock_irq(&ctx
->lock
);
4694 * Mark this event as STATE_DEAD, there is no external reference to it
4697 * Anybody acquiring event->child_mutex after the below loop _must_
4698 * also see this, most importantly inherit_event() which will avoid
4699 * placing more children on the list.
4701 * Thus this guarantees that we will in fact observe and kill _ALL_
4704 event
->state
= PERF_EVENT_STATE_DEAD
;
4705 raw_spin_unlock_irq(&ctx
->lock
);
4707 perf_event_ctx_unlock(event
, ctx
);
4710 mutex_lock(&event
->child_mutex
);
4711 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4714 * Cannot change, child events are not migrated, see the
4715 * comment with perf_event_ctx_lock_nested().
4717 ctx
= READ_ONCE(child
->ctx
);
4719 * Since child_mutex nests inside ctx::mutex, we must jump
4720 * through hoops. We start by grabbing a reference on the ctx.
4722 * Since the event cannot get freed while we hold the
4723 * child_mutex, the context must also exist and have a !0
4729 * Now that we have a ctx ref, we can drop child_mutex, and
4730 * acquire ctx::mutex without fear of it going away. Then we
4731 * can re-acquire child_mutex.
4733 mutex_unlock(&event
->child_mutex
);
4734 mutex_lock(&ctx
->mutex
);
4735 mutex_lock(&event
->child_mutex
);
4738 * Now that we hold ctx::mutex and child_mutex, revalidate our
4739 * state, if child is still the first entry, it didn't get freed
4740 * and we can continue doing so.
4742 tmp
= list_first_entry_or_null(&event
->child_list
,
4743 struct perf_event
, child_list
);
4745 perf_remove_from_context(child
, DETACH_GROUP
);
4746 list_move(&child
->child_list
, &free_list
);
4748 * This matches the refcount bump in inherit_event();
4749 * this can't be the last reference.
4754 mutex_unlock(&event
->child_mutex
);
4755 mutex_unlock(&ctx
->mutex
);
4759 mutex_unlock(&event
->child_mutex
);
4761 list_for_each_entry_safe(child
, tmp
, &free_list
, child_list
) {
4762 void *var
= &child
->ctx
->refcount
;
4764 list_del(&child
->child_list
);
4768 * Wake any perf_event_free_task() waiting for this event to be
4771 smp_mb(); /* pairs with wait_var_event() */
4776 put_event(event
); /* Must be the 'last' reference */
4779 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4782 * Called when the last reference to the file is gone.
4784 static int perf_release(struct inode
*inode
, struct file
*file
)
4786 perf_event_release_kernel(file
->private_data
);
4790 static u64
__perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4792 struct perf_event
*child
;
4798 mutex_lock(&event
->child_mutex
);
4800 (void)perf_event_read(event
, false);
4801 total
+= perf_event_count(event
);
4803 *enabled
+= event
->total_time_enabled
+
4804 atomic64_read(&event
->child_total_time_enabled
);
4805 *running
+= event
->total_time_running
+
4806 atomic64_read(&event
->child_total_time_running
);
4808 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4809 (void)perf_event_read(child
, false);
4810 total
+= perf_event_count(child
);
4811 *enabled
+= child
->total_time_enabled
;
4812 *running
+= child
->total_time_running
;
4814 mutex_unlock(&event
->child_mutex
);
4819 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4821 struct perf_event_context
*ctx
;
4824 ctx
= perf_event_ctx_lock(event
);
4825 count
= __perf_event_read_value(event
, enabled
, running
);
4826 perf_event_ctx_unlock(event
, ctx
);
4830 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4832 static int __perf_read_group_add(struct perf_event
*leader
,
4833 u64 read_format
, u64
*values
)
4835 struct perf_event_context
*ctx
= leader
->ctx
;
4836 struct perf_event
*sub
;
4837 unsigned long flags
;
4838 int n
= 1; /* skip @nr */
4841 ret
= perf_event_read(leader
, true);
4845 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4848 * Since we co-schedule groups, {enabled,running} times of siblings
4849 * will be identical to those of the leader, so we only publish one
4852 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4853 values
[n
++] += leader
->total_time_enabled
+
4854 atomic64_read(&leader
->child_total_time_enabled
);
4857 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4858 values
[n
++] += leader
->total_time_running
+
4859 atomic64_read(&leader
->child_total_time_running
);
4863 * Write {count,id} tuples for every sibling.
4865 values
[n
++] += perf_event_count(leader
);
4866 if (read_format
& PERF_FORMAT_ID
)
4867 values
[n
++] = primary_event_id(leader
);
4869 for_each_sibling_event(sub
, leader
) {
4870 values
[n
++] += perf_event_count(sub
);
4871 if (read_format
& PERF_FORMAT_ID
)
4872 values
[n
++] = primary_event_id(sub
);
4875 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4879 static int perf_read_group(struct perf_event
*event
,
4880 u64 read_format
, char __user
*buf
)
4882 struct perf_event
*leader
= event
->group_leader
, *child
;
4883 struct perf_event_context
*ctx
= leader
->ctx
;
4887 lockdep_assert_held(&ctx
->mutex
);
4889 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4893 values
[0] = 1 + leader
->nr_siblings
;
4896 * By locking the child_mutex of the leader we effectively
4897 * lock the child list of all siblings.. XXX explain how.
4899 mutex_lock(&leader
->child_mutex
);
4901 ret
= __perf_read_group_add(leader
, read_format
, values
);
4905 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4906 ret
= __perf_read_group_add(child
, read_format
, values
);
4911 mutex_unlock(&leader
->child_mutex
);
4913 ret
= event
->read_size
;
4914 if (copy_to_user(buf
, values
, event
->read_size
))
4919 mutex_unlock(&leader
->child_mutex
);
4925 static int perf_read_one(struct perf_event
*event
,
4926 u64 read_format
, char __user
*buf
)
4928 u64 enabled
, running
;
4932 values
[n
++] = __perf_event_read_value(event
, &enabled
, &running
);
4933 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4934 values
[n
++] = enabled
;
4935 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4936 values
[n
++] = running
;
4937 if (read_format
& PERF_FORMAT_ID
)
4938 values
[n
++] = primary_event_id(event
);
4940 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4943 return n
* sizeof(u64
);
4946 static bool is_event_hup(struct perf_event
*event
)
4950 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4953 mutex_lock(&event
->child_mutex
);
4954 no_children
= list_empty(&event
->child_list
);
4955 mutex_unlock(&event
->child_mutex
);
4960 * Read the performance event - simple non blocking version for now
4963 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4965 u64 read_format
= event
->attr
.read_format
;
4969 * Return end-of-file for a read on an event that is in
4970 * error state (i.e. because it was pinned but it couldn't be
4971 * scheduled on to the CPU at some point).
4973 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4976 if (count
< event
->read_size
)
4979 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4980 if (read_format
& PERF_FORMAT_GROUP
)
4981 ret
= perf_read_group(event
, read_format
, buf
);
4983 ret
= perf_read_one(event
, read_format
, buf
);
4989 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4991 struct perf_event
*event
= file
->private_data
;
4992 struct perf_event_context
*ctx
;
4995 ctx
= perf_event_ctx_lock(event
);
4996 ret
= __perf_read(event
, buf
, count
);
4997 perf_event_ctx_unlock(event
, ctx
);
5002 static __poll_t
perf_poll(struct file
*file
, poll_table
*wait
)
5004 struct perf_event
*event
= file
->private_data
;
5005 struct ring_buffer
*rb
;
5006 __poll_t events
= EPOLLHUP
;
5008 poll_wait(file
, &event
->waitq
, wait
);
5010 if (is_event_hup(event
))
5014 * Pin the event->rb by taking event->mmap_mutex; otherwise
5015 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
5017 mutex_lock(&event
->mmap_mutex
);
5020 events
= atomic_xchg(&rb
->poll
, 0);
5021 mutex_unlock(&event
->mmap_mutex
);
5025 static void _perf_event_reset(struct perf_event
*event
)
5027 (void)perf_event_read(event
, false);
5028 local64_set(&event
->count
, 0);
5029 perf_event_update_userpage(event
);
5033 * Holding the top-level event's child_mutex means that any
5034 * descendant process that has inherited this event will block
5035 * in perf_event_exit_event() if it goes to exit, thus satisfying the
5036 * task existence requirements of perf_event_enable/disable.
5038 static void perf_event_for_each_child(struct perf_event
*event
,
5039 void (*func
)(struct perf_event
*))
5041 struct perf_event
*child
;
5043 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5045 mutex_lock(&event
->child_mutex
);
5047 list_for_each_entry(child
, &event
->child_list
, child_list
)
5049 mutex_unlock(&event
->child_mutex
);
5052 static void perf_event_for_each(struct perf_event
*event
,
5053 void (*func
)(struct perf_event
*))
5055 struct perf_event_context
*ctx
= event
->ctx
;
5056 struct perf_event
*sibling
;
5058 lockdep_assert_held(&ctx
->mutex
);
5060 event
= event
->group_leader
;
5062 perf_event_for_each_child(event
, func
);
5063 for_each_sibling_event(sibling
, event
)
5064 perf_event_for_each_child(sibling
, func
);
5067 static void __perf_event_period(struct perf_event
*event
,
5068 struct perf_cpu_context
*cpuctx
,
5069 struct perf_event_context
*ctx
,
5072 u64 value
= *((u64
*)info
);
5075 if (event
->attr
.freq
) {
5076 event
->attr
.sample_freq
= value
;
5078 event
->attr
.sample_period
= value
;
5079 event
->hw
.sample_period
= value
;
5082 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
5084 perf_pmu_disable(ctx
->pmu
);
5086 * We could be throttled; unthrottle now to avoid the tick
5087 * trying to unthrottle while we already re-started the event.
5089 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
5090 event
->hw
.interrupts
= 0;
5091 perf_log_throttle(event
, 1);
5093 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
5096 local64_set(&event
->hw
.period_left
, 0);
5099 event
->pmu
->start(event
, PERF_EF_RELOAD
);
5100 perf_pmu_enable(ctx
->pmu
);
5104 static int perf_event_check_period(struct perf_event
*event
, u64 value
)
5106 return event
->pmu
->check_period(event
, value
);
5109 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
5113 if (!is_sampling_event(event
))
5116 if (copy_from_user(&value
, arg
, sizeof(value
)))
5122 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
5125 if (perf_event_check_period(event
, value
))
5128 if (!event
->attr
.freq
&& (value
& (1ULL << 63)))
5131 event_function_call(event
, __perf_event_period
, &value
);
5136 static const struct file_operations perf_fops
;
5138 static inline int perf_fget_light(int fd
, struct fd
*p
)
5140 struct fd f
= fdget(fd
);
5144 if (f
.file
->f_op
!= &perf_fops
) {
5152 static int perf_event_set_output(struct perf_event
*event
,
5153 struct perf_event
*output_event
);
5154 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
5155 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
5156 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5157 struct perf_event_attr
*attr
);
5159 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
5161 void (*func
)(struct perf_event
*);
5165 case PERF_EVENT_IOC_ENABLE
:
5166 func
= _perf_event_enable
;
5168 case PERF_EVENT_IOC_DISABLE
:
5169 func
= _perf_event_disable
;
5171 case PERF_EVENT_IOC_RESET
:
5172 func
= _perf_event_reset
;
5175 case PERF_EVENT_IOC_REFRESH
:
5176 return _perf_event_refresh(event
, arg
);
5178 case PERF_EVENT_IOC_PERIOD
:
5179 return perf_event_period(event
, (u64 __user
*)arg
);
5181 case PERF_EVENT_IOC_ID
:
5183 u64 id
= primary_event_id(event
);
5185 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
5190 case PERF_EVENT_IOC_SET_OUTPUT
:
5194 struct perf_event
*output_event
;
5196 ret
= perf_fget_light(arg
, &output
);
5199 output_event
= output
.file
->private_data
;
5200 ret
= perf_event_set_output(event
, output_event
);
5203 ret
= perf_event_set_output(event
, NULL
);
5208 case PERF_EVENT_IOC_SET_FILTER
:
5209 return perf_event_set_filter(event
, (void __user
*)arg
);
5211 case PERF_EVENT_IOC_SET_BPF
:
5212 return perf_event_set_bpf_prog(event
, arg
);
5214 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
5215 struct ring_buffer
*rb
;
5218 rb
= rcu_dereference(event
->rb
);
5219 if (!rb
|| !rb
->nr_pages
) {
5223 rb_toggle_paused(rb
, !!arg
);
5228 case PERF_EVENT_IOC_QUERY_BPF
:
5229 return perf_event_query_prog_array(event
, (void __user
*)arg
);
5231 case PERF_EVENT_IOC_MODIFY_ATTRIBUTES
: {
5232 struct perf_event_attr new_attr
;
5233 int err
= perf_copy_attr((struct perf_event_attr __user
*)arg
,
5239 return perf_event_modify_attr(event
, &new_attr
);
5245 if (flags
& PERF_IOC_FLAG_GROUP
)
5246 perf_event_for_each(event
, func
);
5248 perf_event_for_each_child(event
, func
);
5253 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
5255 struct perf_event
*event
= file
->private_data
;
5256 struct perf_event_context
*ctx
;
5259 ctx
= perf_event_ctx_lock(event
);
5260 ret
= _perf_ioctl(event
, cmd
, arg
);
5261 perf_event_ctx_unlock(event
, ctx
);
5266 #ifdef CONFIG_COMPAT
5267 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
5270 switch (_IOC_NR(cmd
)) {
5271 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
5272 case _IOC_NR(PERF_EVENT_IOC_ID
):
5273 case _IOC_NR(PERF_EVENT_IOC_QUERY_BPF
):
5274 case _IOC_NR(PERF_EVENT_IOC_MODIFY_ATTRIBUTES
):
5275 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
5276 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
5277 cmd
&= ~IOCSIZE_MASK
;
5278 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
5282 return perf_ioctl(file
, cmd
, arg
);
5285 # define perf_compat_ioctl NULL
5288 int perf_event_task_enable(void)
5290 struct perf_event_context
*ctx
;
5291 struct perf_event
*event
;
5293 mutex_lock(¤t
->perf_event_mutex
);
5294 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5295 ctx
= perf_event_ctx_lock(event
);
5296 perf_event_for_each_child(event
, _perf_event_enable
);
5297 perf_event_ctx_unlock(event
, ctx
);
5299 mutex_unlock(¤t
->perf_event_mutex
);
5304 int perf_event_task_disable(void)
5306 struct perf_event_context
*ctx
;
5307 struct perf_event
*event
;
5309 mutex_lock(¤t
->perf_event_mutex
);
5310 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
5311 ctx
= perf_event_ctx_lock(event
);
5312 perf_event_for_each_child(event
, _perf_event_disable
);
5313 perf_event_ctx_unlock(event
, ctx
);
5315 mutex_unlock(¤t
->perf_event_mutex
);
5320 static int perf_event_index(struct perf_event
*event
)
5322 if (event
->hw
.state
& PERF_HES_STOPPED
)
5325 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5328 return event
->pmu
->event_idx(event
);
5331 static void calc_timer_values(struct perf_event
*event
,
5338 *now
= perf_clock();
5339 ctx_time
= event
->shadow_ctx_time
+ *now
;
5340 __perf_update_times(event
, ctx_time
, enabled
, running
);
5343 static void perf_event_init_userpage(struct perf_event
*event
)
5345 struct perf_event_mmap_page
*userpg
;
5346 struct ring_buffer
*rb
;
5349 rb
= rcu_dereference(event
->rb
);
5353 userpg
= rb
->user_page
;
5355 /* Allow new userspace to detect that bit 0 is deprecated */
5356 userpg
->cap_bit0_is_deprecated
= 1;
5357 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
5358 userpg
->data_offset
= PAGE_SIZE
;
5359 userpg
->data_size
= perf_data_size(rb
);
5365 void __weak
arch_perf_update_userpage(
5366 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
5371 * Callers need to ensure there can be no nesting of this function, otherwise
5372 * the seqlock logic goes bad. We can not serialize this because the arch
5373 * code calls this from NMI context.
5375 void perf_event_update_userpage(struct perf_event
*event
)
5377 struct perf_event_mmap_page
*userpg
;
5378 struct ring_buffer
*rb
;
5379 u64 enabled
, running
, now
;
5382 rb
= rcu_dereference(event
->rb
);
5387 * compute total_time_enabled, total_time_running
5388 * based on snapshot values taken when the event
5389 * was last scheduled in.
5391 * we cannot simply called update_context_time()
5392 * because of locking issue as we can be called in
5395 calc_timer_values(event
, &now
, &enabled
, &running
);
5397 userpg
= rb
->user_page
;
5399 * Disable preemption to guarantee consistent time stamps are stored to
5405 userpg
->index
= perf_event_index(event
);
5406 userpg
->offset
= perf_event_count(event
);
5408 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
5410 userpg
->time_enabled
= enabled
+
5411 atomic64_read(&event
->child_total_time_enabled
);
5413 userpg
->time_running
= running
+
5414 atomic64_read(&event
->child_total_time_running
);
5416 arch_perf_update_userpage(event
, userpg
, now
);
5424 EXPORT_SYMBOL_GPL(perf_event_update_userpage
);
5426 static vm_fault_t
perf_mmap_fault(struct vm_fault
*vmf
)
5428 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5429 struct ring_buffer
*rb
;
5430 vm_fault_t ret
= VM_FAULT_SIGBUS
;
5432 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5433 if (vmf
->pgoff
== 0)
5439 rb
= rcu_dereference(event
->rb
);
5443 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5446 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5450 get_page(vmf
->page
);
5451 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5452 vmf
->page
->index
= vmf
->pgoff
;
5461 static void ring_buffer_attach(struct perf_event
*event
,
5462 struct ring_buffer
*rb
)
5464 struct ring_buffer
*old_rb
= NULL
;
5465 unsigned long flags
;
5469 * Should be impossible, we set this when removing
5470 * event->rb_entry and wait/clear when adding event->rb_entry.
5472 WARN_ON_ONCE(event
->rcu_pending
);
5475 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5476 list_del_rcu(&event
->rb_entry
);
5477 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5479 event
->rcu_batches
= get_state_synchronize_rcu();
5480 event
->rcu_pending
= 1;
5484 if (event
->rcu_pending
) {
5485 cond_synchronize_rcu(event
->rcu_batches
);
5486 event
->rcu_pending
= 0;
5489 spin_lock_irqsave(&rb
->event_lock
, flags
);
5490 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5491 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5495 * Avoid racing with perf_mmap_close(AUX): stop the event
5496 * before swizzling the event::rb pointer; if it's getting
5497 * unmapped, its aux_mmap_count will be 0 and it won't
5498 * restart. See the comment in __perf_pmu_output_stop().
5500 * Data will inevitably be lost when set_output is done in
5501 * mid-air, but then again, whoever does it like this is
5502 * not in for the data anyway.
5505 perf_event_stop(event
, 0);
5507 rcu_assign_pointer(event
->rb
, rb
);
5510 ring_buffer_put(old_rb
);
5512 * Since we detached before setting the new rb, so that we
5513 * could attach the new rb, we could have missed a wakeup.
5516 wake_up_all(&event
->waitq
);
5520 static void ring_buffer_wakeup(struct perf_event
*event
)
5522 struct ring_buffer
*rb
;
5525 rb
= rcu_dereference(event
->rb
);
5527 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5528 wake_up_all(&event
->waitq
);
5533 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5535 struct ring_buffer
*rb
;
5538 rb
= rcu_dereference(event
->rb
);
5540 if (!refcount_inc_not_zero(&rb
->refcount
))
5548 void ring_buffer_put(struct ring_buffer
*rb
)
5550 if (!refcount_dec_and_test(&rb
->refcount
))
5553 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5555 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5558 static void perf_mmap_open(struct vm_area_struct
*vma
)
5560 struct perf_event
*event
= vma
->vm_file
->private_data
;
5562 atomic_inc(&event
->mmap_count
);
5563 atomic_inc(&event
->rb
->mmap_count
);
5566 atomic_inc(&event
->rb
->aux_mmap_count
);
5568 if (event
->pmu
->event_mapped
)
5569 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5572 static void perf_pmu_output_stop(struct perf_event
*event
);
5575 * A buffer can be mmap()ed multiple times; either directly through the same
5576 * event, or through other events by use of perf_event_set_output().
5578 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5579 * the buffer here, where we still have a VM context. This means we need
5580 * to detach all events redirecting to us.
5582 static void perf_mmap_close(struct vm_area_struct
*vma
)
5584 struct perf_event
*event
= vma
->vm_file
->private_data
;
5586 struct ring_buffer
*rb
= ring_buffer_get(event
);
5587 struct user_struct
*mmap_user
= rb
->mmap_user
;
5588 int mmap_locked
= rb
->mmap_locked
;
5589 unsigned long size
= perf_data_size(rb
);
5591 if (event
->pmu
->event_unmapped
)
5592 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5595 * rb->aux_mmap_count will always drop before rb->mmap_count and
5596 * event->mmap_count, so it is ok to use event->mmap_mutex to
5597 * serialize with perf_mmap here.
5599 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5600 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5602 * Stop all AUX events that are writing to this buffer,
5603 * so that we can free its AUX pages and corresponding PMU
5604 * data. Note that after rb::aux_mmap_count dropped to zero,
5605 * they won't start any more (see perf_aux_output_begin()).
5607 perf_pmu_output_stop(event
);
5609 /* now it's safe to free the pages */
5610 if (!rb
->aux_mmap_locked
)
5611 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5613 atomic64_sub(rb
->aux_mmap_locked
, &vma
->vm_mm
->pinned_vm
);
5615 /* this has to be the last one */
5617 WARN_ON_ONCE(refcount_read(&rb
->aux_refcount
));
5619 mutex_unlock(&event
->mmap_mutex
);
5622 atomic_dec(&rb
->mmap_count
);
5624 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5627 ring_buffer_attach(event
, NULL
);
5628 mutex_unlock(&event
->mmap_mutex
);
5630 /* If there's still other mmap()s of this buffer, we're done. */
5631 if (atomic_read(&rb
->mmap_count
))
5635 * No other mmap()s, detach from all other events that might redirect
5636 * into the now unreachable buffer. Somewhat complicated by the
5637 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5641 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5642 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5644 * This event is en-route to free_event() which will
5645 * detach it and remove it from the list.
5651 mutex_lock(&event
->mmap_mutex
);
5653 * Check we didn't race with perf_event_set_output() which can
5654 * swizzle the rb from under us while we were waiting to
5655 * acquire mmap_mutex.
5657 * If we find a different rb; ignore this event, a next
5658 * iteration will no longer find it on the list. We have to
5659 * still restart the iteration to make sure we're not now
5660 * iterating the wrong list.
5662 if (event
->rb
== rb
)
5663 ring_buffer_attach(event
, NULL
);
5665 mutex_unlock(&event
->mmap_mutex
);
5669 * Restart the iteration; either we're on the wrong list or
5670 * destroyed its integrity by doing a deletion.
5677 * It could be there's still a few 0-ref events on the list; they'll
5678 * get cleaned up by free_event() -- they'll also still have their
5679 * ref on the rb and will free it whenever they are done with it.
5681 * Aside from that, this buffer is 'fully' detached and unmapped,
5682 * undo the VM accounting.
5685 atomic_long_sub((size
>> PAGE_SHIFT
) + 1 - mmap_locked
,
5686 &mmap_user
->locked_vm
);
5687 atomic64_sub(mmap_locked
, &vma
->vm_mm
->pinned_vm
);
5688 free_uid(mmap_user
);
5691 ring_buffer_put(rb
); /* could be last */
5694 static const struct vm_operations_struct perf_mmap_vmops
= {
5695 .open
= perf_mmap_open
,
5696 .close
= perf_mmap_close
, /* non mergeable */
5697 .fault
= perf_mmap_fault
,
5698 .page_mkwrite
= perf_mmap_fault
,
5701 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5703 struct perf_event
*event
= file
->private_data
;
5704 unsigned long user_locked
, user_lock_limit
;
5705 struct user_struct
*user
= current_user();
5706 unsigned long locked
, lock_limit
;
5707 struct ring_buffer
*rb
= NULL
;
5708 unsigned long vma_size
;
5709 unsigned long nr_pages
;
5710 long user_extra
= 0, extra
= 0;
5711 int ret
= 0, flags
= 0;
5714 * Don't allow mmap() of inherited per-task counters. This would
5715 * create a performance issue due to all children writing to the
5718 if (event
->cpu
== -1 && event
->attr
.inherit
)
5721 if (!(vma
->vm_flags
& VM_SHARED
))
5724 vma_size
= vma
->vm_end
- vma
->vm_start
;
5726 if (vma
->vm_pgoff
== 0) {
5727 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5730 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5731 * mapped, all subsequent mappings should have the same size
5732 * and offset. Must be above the normal perf buffer.
5734 u64 aux_offset
, aux_size
;
5739 nr_pages
= vma_size
/ PAGE_SIZE
;
5741 mutex_lock(&event
->mmap_mutex
);
5748 aux_offset
= READ_ONCE(rb
->user_page
->aux_offset
);
5749 aux_size
= READ_ONCE(rb
->user_page
->aux_size
);
5751 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5754 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5757 /* already mapped with a different offset */
5758 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5761 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5764 /* already mapped with a different size */
5765 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5768 if (!is_power_of_2(nr_pages
))
5771 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5774 if (rb_has_aux(rb
)) {
5775 atomic_inc(&rb
->aux_mmap_count
);
5780 atomic_set(&rb
->aux_mmap_count
, 1);
5781 user_extra
= nr_pages
;
5787 * If we have rb pages ensure they're a power-of-two number, so we
5788 * can do bitmasks instead of modulo.
5790 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5793 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5796 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5798 mutex_lock(&event
->mmap_mutex
);
5800 if (event
->rb
->nr_pages
!= nr_pages
) {
5805 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5807 * Raced against perf_mmap_close() through
5808 * perf_event_set_output(). Try again, hope for better
5811 mutex_unlock(&event
->mmap_mutex
);
5818 user_extra
= nr_pages
+ 1;
5821 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5824 * Increase the limit linearly with more CPUs:
5826 user_lock_limit
*= num_online_cpus();
5828 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5830 if (user_locked
<= user_lock_limit
) {
5831 /* charge all to locked_vm */
5832 } else if (atomic_long_read(&user
->locked_vm
) >= user_lock_limit
) {
5833 /* charge all to pinned_vm */
5838 * charge locked_vm until it hits user_lock_limit;
5839 * charge the rest from pinned_vm
5841 extra
= user_locked
- user_lock_limit
;
5842 user_extra
-= extra
;
5845 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5846 lock_limit
>>= PAGE_SHIFT
;
5847 locked
= atomic64_read(&vma
->vm_mm
->pinned_vm
) + extra
;
5849 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5850 !capable(CAP_IPC_LOCK
)) {
5855 WARN_ON(!rb
&& event
->rb
);
5857 if (vma
->vm_flags
& VM_WRITE
)
5858 flags
|= RING_BUFFER_WRITABLE
;
5861 rb
= rb_alloc(nr_pages
,
5862 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5870 atomic_set(&rb
->mmap_count
, 1);
5871 rb
->mmap_user
= get_current_user();
5872 rb
->mmap_locked
= extra
;
5874 ring_buffer_attach(event
, rb
);
5876 perf_event_init_userpage(event
);
5877 perf_event_update_userpage(event
);
5879 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5880 event
->attr
.aux_watermark
, flags
);
5882 rb
->aux_mmap_locked
= extra
;
5887 atomic_long_add(user_extra
, &user
->locked_vm
);
5888 atomic64_add(extra
, &vma
->vm_mm
->pinned_vm
);
5890 atomic_inc(&event
->mmap_count
);
5892 atomic_dec(&rb
->mmap_count
);
5895 mutex_unlock(&event
->mmap_mutex
);
5898 * Since pinned accounting is per vm we cannot allow fork() to copy our
5901 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5902 vma
->vm_ops
= &perf_mmap_vmops
;
5904 if (event
->pmu
->event_mapped
)
5905 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5910 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5912 struct inode
*inode
= file_inode(filp
);
5913 struct perf_event
*event
= filp
->private_data
;
5917 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5918 inode_unlock(inode
);
5926 static const struct file_operations perf_fops
= {
5927 .llseek
= no_llseek
,
5928 .release
= perf_release
,
5931 .unlocked_ioctl
= perf_ioctl
,
5932 .compat_ioctl
= perf_compat_ioctl
,
5934 .fasync
= perf_fasync
,
5940 * If there's data, ensure we set the poll() state and publish everything
5941 * to user-space before waking everybody up.
5944 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5946 /* only the parent has fasync state */
5948 event
= event
->parent
;
5949 return &event
->fasync
;
5952 void perf_event_wakeup(struct perf_event
*event
)
5954 ring_buffer_wakeup(event
);
5956 if (event
->pending_kill
) {
5957 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5958 event
->pending_kill
= 0;
5962 static void perf_pending_event_disable(struct perf_event
*event
)
5964 int cpu
= READ_ONCE(event
->pending_disable
);
5969 if (cpu
== smp_processor_id()) {
5970 WRITE_ONCE(event
->pending_disable
, -1);
5971 perf_event_disable_local(event
);
5978 * perf_event_disable_inatomic()
5979 * @pending_disable = CPU-A;
5983 * @pending_disable = -1;
5986 * perf_event_disable_inatomic()
5987 * @pending_disable = CPU-B;
5988 * irq_work_queue(); // FAILS
5991 * perf_pending_event()
5993 * But the event runs on CPU-B and wants disabling there.
5995 irq_work_queue_on(&event
->pending
, cpu
);
5998 static void perf_pending_event(struct irq_work
*entry
)
6000 struct perf_event
*event
= container_of(entry
, struct perf_event
, pending
);
6003 rctx
= perf_swevent_get_recursion_context();
6005 * If we 'fail' here, that's OK, it means recursion is already disabled
6006 * and we won't recurse 'further'.
6009 perf_pending_event_disable(event
);
6011 if (event
->pending_wakeup
) {
6012 event
->pending_wakeup
= 0;
6013 perf_event_wakeup(event
);
6017 perf_swevent_put_recursion_context(rctx
);
6021 * We assume there is only KVM supporting the callbacks.
6022 * Later on, we might change it to a list if there is
6023 * another virtualization implementation supporting the callbacks.
6025 struct perf_guest_info_callbacks
*perf_guest_cbs
;
6027 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6029 perf_guest_cbs
= cbs
;
6032 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
6034 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
6036 perf_guest_cbs
= NULL
;
6039 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
6042 perf_output_sample_regs(struct perf_output_handle
*handle
,
6043 struct pt_regs
*regs
, u64 mask
)
6046 DECLARE_BITMAP(_mask
, 64);
6048 bitmap_from_u64(_mask
, mask
);
6049 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
6052 val
= perf_reg_value(regs
, bit
);
6053 perf_output_put(handle
, val
);
6057 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
6058 struct pt_regs
*regs
,
6059 struct pt_regs
*regs_user_copy
)
6061 if (user_mode(regs
)) {
6062 regs_user
->abi
= perf_reg_abi(current
);
6063 regs_user
->regs
= regs
;
6064 } else if (!(current
->flags
& PF_KTHREAD
)) {
6065 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
6067 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
6068 regs_user
->regs
= NULL
;
6072 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
6073 struct pt_regs
*regs
)
6075 regs_intr
->regs
= regs
;
6076 regs_intr
->abi
= perf_reg_abi(current
);
6081 * Get remaining task size from user stack pointer.
6083 * It'd be better to take stack vma map and limit this more
6084 * precisely, but there's no way to get it safely under interrupt,
6085 * so using TASK_SIZE as limit.
6087 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
6089 unsigned long addr
= perf_user_stack_pointer(regs
);
6091 if (!addr
|| addr
>= TASK_SIZE
)
6094 return TASK_SIZE
- addr
;
6098 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
6099 struct pt_regs
*regs
)
6103 /* No regs, no stack pointer, no dump. */
6108 * Check if we fit in with the requested stack size into the:
6110 * If we don't, we limit the size to the TASK_SIZE.
6112 * - remaining sample size
6113 * If we don't, we customize the stack size to
6114 * fit in to the remaining sample size.
6117 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
6118 stack_size
= min(stack_size
, (u16
) task_size
);
6120 /* Current header size plus static size and dynamic size. */
6121 header_size
+= 2 * sizeof(u64
);
6123 /* Do we fit in with the current stack dump size? */
6124 if ((u16
) (header_size
+ stack_size
) < header_size
) {
6126 * If we overflow the maximum size for the sample,
6127 * we customize the stack dump size to fit in.
6129 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
6130 stack_size
= round_up(stack_size
, sizeof(u64
));
6137 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
6138 struct pt_regs
*regs
)
6140 /* Case of a kernel thread, nothing to dump */
6143 perf_output_put(handle
, size
);
6153 * - the size requested by user or the best one we can fit
6154 * in to the sample max size
6156 * - user stack dump data
6158 * - the actual dumped size
6162 perf_output_put(handle
, dump_size
);
6165 sp
= perf_user_stack_pointer(regs
);
6168 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
6170 dyn_size
= dump_size
- rem
;
6172 perf_output_skip(handle
, rem
);
6175 perf_output_put(handle
, dyn_size
);
6179 static void __perf_event_header__init_id(struct perf_event_header
*header
,
6180 struct perf_sample_data
*data
,
6181 struct perf_event
*event
)
6183 u64 sample_type
= event
->attr
.sample_type
;
6185 data
->type
= sample_type
;
6186 header
->size
+= event
->id_header_size
;
6188 if (sample_type
& PERF_SAMPLE_TID
) {
6189 /* namespace issues */
6190 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
6191 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
6194 if (sample_type
& PERF_SAMPLE_TIME
)
6195 data
->time
= perf_event_clock(event
);
6197 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
6198 data
->id
= primary_event_id(event
);
6200 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6201 data
->stream_id
= event
->id
;
6203 if (sample_type
& PERF_SAMPLE_CPU
) {
6204 data
->cpu_entry
.cpu
= raw_smp_processor_id();
6205 data
->cpu_entry
.reserved
= 0;
6209 void perf_event_header__init_id(struct perf_event_header
*header
,
6210 struct perf_sample_data
*data
,
6211 struct perf_event
*event
)
6213 if (event
->attr
.sample_id_all
)
6214 __perf_event_header__init_id(header
, data
, event
);
6217 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
6218 struct perf_sample_data
*data
)
6220 u64 sample_type
= data
->type
;
6222 if (sample_type
& PERF_SAMPLE_TID
)
6223 perf_output_put(handle
, data
->tid_entry
);
6225 if (sample_type
& PERF_SAMPLE_TIME
)
6226 perf_output_put(handle
, data
->time
);
6228 if (sample_type
& PERF_SAMPLE_ID
)
6229 perf_output_put(handle
, data
->id
);
6231 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6232 perf_output_put(handle
, data
->stream_id
);
6234 if (sample_type
& PERF_SAMPLE_CPU
)
6235 perf_output_put(handle
, data
->cpu_entry
);
6237 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6238 perf_output_put(handle
, data
->id
);
6241 void perf_event__output_id_sample(struct perf_event
*event
,
6242 struct perf_output_handle
*handle
,
6243 struct perf_sample_data
*sample
)
6245 if (event
->attr
.sample_id_all
)
6246 __perf_event__output_id_sample(handle
, sample
);
6249 static void perf_output_read_one(struct perf_output_handle
*handle
,
6250 struct perf_event
*event
,
6251 u64 enabled
, u64 running
)
6253 u64 read_format
= event
->attr
.read_format
;
6257 values
[n
++] = perf_event_count(event
);
6258 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
6259 values
[n
++] = enabled
+
6260 atomic64_read(&event
->child_total_time_enabled
);
6262 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
6263 values
[n
++] = running
+
6264 atomic64_read(&event
->child_total_time_running
);
6266 if (read_format
& PERF_FORMAT_ID
)
6267 values
[n
++] = primary_event_id(event
);
6269 __output_copy(handle
, values
, n
* sizeof(u64
));
6272 static void perf_output_read_group(struct perf_output_handle
*handle
,
6273 struct perf_event
*event
,
6274 u64 enabled
, u64 running
)
6276 struct perf_event
*leader
= event
->group_leader
, *sub
;
6277 u64 read_format
= event
->attr
.read_format
;
6281 values
[n
++] = 1 + leader
->nr_siblings
;
6283 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
6284 values
[n
++] = enabled
;
6286 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
6287 values
[n
++] = running
;
6289 if ((leader
!= event
) &&
6290 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
6291 leader
->pmu
->read(leader
);
6293 values
[n
++] = perf_event_count(leader
);
6294 if (read_format
& PERF_FORMAT_ID
)
6295 values
[n
++] = primary_event_id(leader
);
6297 __output_copy(handle
, values
, n
* sizeof(u64
));
6299 for_each_sibling_event(sub
, leader
) {
6302 if ((sub
!= event
) &&
6303 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
6304 sub
->pmu
->read(sub
);
6306 values
[n
++] = perf_event_count(sub
);
6307 if (read_format
& PERF_FORMAT_ID
)
6308 values
[n
++] = primary_event_id(sub
);
6310 __output_copy(handle
, values
, n
* sizeof(u64
));
6314 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
6315 PERF_FORMAT_TOTAL_TIME_RUNNING)
6318 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
6320 * The problem is that its both hard and excessively expensive to iterate the
6321 * child list, not to mention that its impossible to IPI the children running
6322 * on another CPU, from interrupt/NMI context.
6324 static void perf_output_read(struct perf_output_handle
*handle
,
6325 struct perf_event
*event
)
6327 u64 enabled
= 0, running
= 0, now
;
6328 u64 read_format
= event
->attr
.read_format
;
6331 * compute total_time_enabled, total_time_running
6332 * based on snapshot values taken when the event
6333 * was last scheduled in.
6335 * we cannot simply called update_context_time()
6336 * because of locking issue as we are called in
6339 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
6340 calc_timer_values(event
, &now
, &enabled
, &running
);
6342 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
6343 perf_output_read_group(handle
, event
, enabled
, running
);
6345 perf_output_read_one(handle
, event
, enabled
, running
);
6348 void perf_output_sample(struct perf_output_handle
*handle
,
6349 struct perf_event_header
*header
,
6350 struct perf_sample_data
*data
,
6351 struct perf_event
*event
)
6353 u64 sample_type
= data
->type
;
6355 perf_output_put(handle
, *header
);
6357 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
6358 perf_output_put(handle
, data
->id
);
6360 if (sample_type
& PERF_SAMPLE_IP
)
6361 perf_output_put(handle
, data
->ip
);
6363 if (sample_type
& PERF_SAMPLE_TID
)
6364 perf_output_put(handle
, data
->tid_entry
);
6366 if (sample_type
& PERF_SAMPLE_TIME
)
6367 perf_output_put(handle
, data
->time
);
6369 if (sample_type
& PERF_SAMPLE_ADDR
)
6370 perf_output_put(handle
, data
->addr
);
6372 if (sample_type
& PERF_SAMPLE_ID
)
6373 perf_output_put(handle
, data
->id
);
6375 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
6376 perf_output_put(handle
, data
->stream_id
);
6378 if (sample_type
& PERF_SAMPLE_CPU
)
6379 perf_output_put(handle
, data
->cpu_entry
);
6381 if (sample_type
& PERF_SAMPLE_PERIOD
)
6382 perf_output_put(handle
, data
->period
);
6384 if (sample_type
& PERF_SAMPLE_READ
)
6385 perf_output_read(handle
, event
);
6387 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6390 size
+= data
->callchain
->nr
;
6391 size
*= sizeof(u64
);
6392 __output_copy(handle
, data
->callchain
, size
);
6395 if (sample_type
& PERF_SAMPLE_RAW
) {
6396 struct perf_raw_record
*raw
= data
->raw
;
6399 struct perf_raw_frag
*frag
= &raw
->frag
;
6401 perf_output_put(handle
, raw
->size
);
6404 __output_custom(handle
, frag
->copy
,
6405 frag
->data
, frag
->size
);
6407 __output_copy(handle
, frag
->data
,
6410 if (perf_raw_frag_last(frag
))
6415 __output_skip(handle
, NULL
, frag
->pad
);
6421 .size
= sizeof(u32
),
6424 perf_output_put(handle
, raw
);
6428 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6429 if (data
->br_stack
) {
6432 size
= data
->br_stack
->nr
6433 * sizeof(struct perf_branch_entry
);
6435 perf_output_put(handle
, data
->br_stack
->nr
);
6436 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
6439 * we always store at least the value of nr
6442 perf_output_put(handle
, nr
);
6446 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6447 u64 abi
= data
->regs_user
.abi
;
6450 * If there are no regs to dump, notice it through
6451 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6453 perf_output_put(handle
, abi
);
6456 u64 mask
= event
->attr
.sample_regs_user
;
6457 perf_output_sample_regs(handle
,
6458 data
->regs_user
.regs
,
6463 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6464 perf_output_sample_ustack(handle
,
6465 data
->stack_user_size
,
6466 data
->regs_user
.regs
);
6469 if (sample_type
& PERF_SAMPLE_WEIGHT
)
6470 perf_output_put(handle
, data
->weight
);
6472 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
6473 perf_output_put(handle
, data
->data_src
.val
);
6475 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
6476 perf_output_put(handle
, data
->txn
);
6478 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6479 u64 abi
= data
->regs_intr
.abi
;
6481 * If there are no regs to dump, notice it through
6482 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6484 perf_output_put(handle
, abi
);
6487 u64 mask
= event
->attr
.sample_regs_intr
;
6489 perf_output_sample_regs(handle
,
6490 data
->regs_intr
.regs
,
6495 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6496 perf_output_put(handle
, data
->phys_addr
);
6498 if (!event
->attr
.watermark
) {
6499 int wakeup_events
= event
->attr
.wakeup_events
;
6501 if (wakeup_events
) {
6502 struct ring_buffer
*rb
= handle
->rb
;
6503 int events
= local_inc_return(&rb
->events
);
6505 if (events
>= wakeup_events
) {
6506 local_sub(wakeup_events
, &rb
->events
);
6507 local_inc(&rb
->wakeup
);
6513 static u64
perf_virt_to_phys(u64 virt
)
6516 struct page
*p
= NULL
;
6521 if (virt
>= TASK_SIZE
) {
6522 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6523 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6524 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6525 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6528 * Walking the pages tables for user address.
6529 * Interrupts are disabled, so it prevents any tear down
6530 * of the page tables.
6531 * Try IRQ-safe __get_user_pages_fast first.
6532 * If failed, leave phys_addr as 0.
6534 if ((current
->mm
!= NULL
) &&
6535 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
6536 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6545 static struct perf_callchain_entry __empty_callchain
= { .nr
= 0, };
6547 struct perf_callchain_entry
*
6548 perf_callchain(struct perf_event
*event
, struct pt_regs
*regs
)
6550 bool kernel
= !event
->attr
.exclude_callchain_kernel
;
6551 bool user
= !event
->attr
.exclude_callchain_user
;
6552 /* Disallow cross-task user callchains. */
6553 bool crosstask
= event
->ctx
->task
&& event
->ctx
->task
!= current
;
6554 const u32 max_stack
= event
->attr
.sample_max_stack
;
6555 struct perf_callchain_entry
*callchain
;
6557 if (!kernel
&& !user
)
6558 return &__empty_callchain
;
6560 callchain
= get_perf_callchain(regs
, 0, kernel
, user
,
6561 max_stack
, crosstask
, true);
6562 return callchain
?: &__empty_callchain
;
6565 void perf_prepare_sample(struct perf_event_header
*header
,
6566 struct perf_sample_data
*data
,
6567 struct perf_event
*event
,
6568 struct pt_regs
*regs
)
6570 u64 sample_type
= event
->attr
.sample_type
;
6572 header
->type
= PERF_RECORD_SAMPLE
;
6573 header
->size
= sizeof(*header
) + event
->header_size
;
6576 header
->misc
|= perf_misc_flags(regs
);
6578 __perf_event_header__init_id(header
, data
, event
);
6580 if (sample_type
& PERF_SAMPLE_IP
)
6581 data
->ip
= perf_instruction_pointer(regs
);
6583 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6586 if (!(sample_type
& __PERF_SAMPLE_CALLCHAIN_EARLY
))
6587 data
->callchain
= perf_callchain(event
, regs
);
6589 size
+= data
->callchain
->nr
;
6591 header
->size
+= size
* sizeof(u64
);
6594 if (sample_type
& PERF_SAMPLE_RAW
) {
6595 struct perf_raw_record
*raw
= data
->raw
;
6599 struct perf_raw_frag
*frag
= &raw
->frag
;
6604 if (perf_raw_frag_last(frag
))
6609 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6610 raw
->size
= size
- sizeof(u32
);
6611 frag
->pad
= raw
->size
- sum
;
6616 header
->size
+= size
;
6619 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6620 int size
= sizeof(u64
); /* nr */
6621 if (data
->br_stack
) {
6622 size
+= data
->br_stack
->nr
6623 * sizeof(struct perf_branch_entry
);
6625 header
->size
+= size
;
6628 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6629 perf_sample_regs_user(&data
->regs_user
, regs
,
6630 &data
->regs_user_copy
);
6632 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6633 /* regs dump ABI info */
6634 int size
= sizeof(u64
);
6636 if (data
->regs_user
.regs
) {
6637 u64 mask
= event
->attr
.sample_regs_user
;
6638 size
+= hweight64(mask
) * sizeof(u64
);
6641 header
->size
+= size
;
6644 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6646 * Either we need PERF_SAMPLE_STACK_USER bit to be always
6647 * processed as the last one or have additional check added
6648 * in case new sample type is added, because we could eat
6649 * up the rest of the sample size.
6651 u16 stack_size
= event
->attr
.sample_stack_user
;
6652 u16 size
= sizeof(u64
);
6654 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6655 data
->regs_user
.regs
);
6658 * If there is something to dump, add space for the dump
6659 * itself and for the field that tells the dynamic size,
6660 * which is how many have been actually dumped.
6663 size
+= sizeof(u64
) + stack_size
;
6665 data
->stack_user_size
= stack_size
;
6666 header
->size
+= size
;
6669 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6670 /* regs dump ABI info */
6671 int size
= sizeof(u64
);
6673 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6675 if (data
->regs_intr
.regs
) {
6676 u64 mask
= event
->attr
.sample_regs_intr
;
6678 size
+= hweight64(mask
) * sizeof(u64
);
6681 header
->size
+= size
;
6684 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6685 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6688 static __always_inline
int
6689 __perf_event_output(struct perf_event
*event
,
6690 struct perf_sample_data
*data
,
6691 struct pt_regs
*regs
,
6692 int (*output_begin
)(struct perf_output_handle
*,
6693 struct perf_event
*,
6696 struct perf_output_handle handle
;
6697 struct perf_event_header header
;
6700 /* protect the callchain buffers */
6703 perf_prepare_sample(&header
, data
, event
, regs
);
6705 err
= output_begin(&handle
, event
, header
.size
);
6709 perf_output_sample(&handle
, &header
, data
, event
);
6711 perf_output_end(&handle
);
6719 perf_event_output_forward(struct perf_event
*event
,
6720 struct perf_sample_data
*data
,
6721 struct pt_regs
*regs
)
6723 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6727 perf_event_output_backward(struct perf_event
*event
,
6728 struct perf_sample_data
*data
,
6729 struct pt_regs
*regs
)
6731 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6735 perf_event_output(struct perf_event
*event
,
6736 struct perf_sample_data
*data
,
6737 struct pt_regs
*regs
)
6739 return __perf_event_output(event
, data
, regs
, perf_output_begin
);
6746 struct perf_read_event
{
6747 struct perf_event_header header
;
6754 perf_event_read_event(struct perf_event
*event
,
6755 struct task_struct
*task
)
6757 struct perf_output_handle handle
;
6758 struct perf_sample_data sample
;
6759 struct perf_read_event read_event
= {
6761 .type
= PERF_RECORD_READ
,
6763 .size
= sizeof(read_event
) + event
->read_size
,
6765 .pid
= perf_event_pid(event
, task
),
6766 .tid
= perf_event_tid(event
, task
),
6770 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6771 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6775 perf_output_put(&handle
, read_event
);
6776 perf_output_read(&handle
, event
);
6777 perf_event__output_id_sample(event
, &handle
, &sample
);
6779 perf_output_end(&handle
);
6782 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6785 perf_iterate_ctx(struct perf_event_context
*ctx
,
6786 perf_iterate_f output
,
6787 void *data
, bool all
)
6789 struct perf_event
*event
;
6791 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6793 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6795 if (!event_filter_match(event
))
6799 output(event
, data
);
6803 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6805 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6806 struct perf_event
*event
;
6808 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6810 * Skip events that are not fully formed yet; ensure that
6811 * if we observe event->ctx, both event and ctx will be
6812 * complete enough. See perf_install_in_context().
6814 if (!smp_load_acquire(&event
->ctx
))
6817 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6819 if (!event_filter_match(event
))
6821 output(event
, data
);
6826 * Iterate all events that need to receive side-band events.
6828 * For new callers; ensure that account_pmu_sb_event() includes
6829 * your event, otherwise it might not get delivered.
6832 perf_iterate_sb(perf_iterate_f output
, void *data
,
6833 struct perf_event_context
*task_ctx
)
6835 struct perf_event_context
*ctx
;
6842 * If we have task_ctx != NULL we only notify the task context itself.
6843 * The task_ctx is set only for EXIT events before releasing task
6847 perf_iterate_ctx(task_ctx
, output
, data
, false);
6851 perf_iterate_sb_cpu(output
, data
);
6853 for_each_task_context_nr(ctxn
) {
6854 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6856 perf_iterate_ctx(ctx
, output
, data
, false);
6864 * Clear all file-based filters at exec, they'll have to be
6865 * re-instated when/if these objects are mmapped again.
6867 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6869 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6870 struct perf_addr_filter
*filter
;
6871 unsigned int restart
= 0, count
= 0;
6872 unsigned long flags
;
6874 if (!has_addr_filter(event
))
6877 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6878 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6879 if (filter
->path
.dentry
) {
6880 event
->addr_filter_ranges
[count
].start
= 0;
6881 event
->addr_filter_ranges
[count
].size
= 0;
6889 event
->addr_filters_gen
++;
6890 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6893 perf_event_stop(event
, 1);
6896 void perf_event_exec(void)
6898 struct perf_event_context
*ctx
;
6902 for_each_task_context_nr(ctxn
) {
6903 ctx
= current
->perf_event_ctxp
[ctxn
];
6907 perf_event_enable_on_exec(ctxn
);
6909 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6915 struct remote_output
{
6916 struct ring_buffer
*rb
;
6920 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6922 struct perf_event
*parent
= event
->parent
;
6923 struct remote_output
*ro
= data
;
6924 struct ring_buffer
*rb
= ro
->rb
;
6925 struct stop_event_data sd
= {
6929 if (!has_aux(event
))
6936 * In case of inheritance, it will be the parent that links to the
6937 * ring-buffer, but it will be the child that's actually using it.
6939 * We are using event::rb to determine if the event should be stopped,
6940 * however this may race with ring_buffer_attach() (through set_output),
6941 * which will make us skip the event that actually needs to be stopped.
6942 * So ring_buffer_attach() has to stop an aux event before re-assigning
6945 if (rcu_dereference(parent
->rb
) == rb
)
6946 ro
->err
= __perf_event_stop(&sd
);
6949 static int __perf_pmu_output_stop(void *info
)
6951 struct perf_event
*event
= info
;
6952 struct pmu
*pmu
= event
->ctx
->pmu
;
6953 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6954 struct remote_output ro
= {
6959 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6960 if (cpuctx
->task_ctx
)
6961 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6968 static void perf_pmu_output_stop(struct perf_event
*event
)
6970 struct perf_event
*iter
;
6975 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6977 * For per-CPU events, we need to make sure that neither they
6978 * nor their children are running; for cpu==-1 events it's
6979 * sufficient to stop the event itself if it's active, since
6980 * it can't have children.
6984 cpu
= READ_ONCE(iter
->oncpu
);
6989 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6990 if (err
== -EAGAIN
) {
6999 * task tracking -- fork/exit
7001 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
7004 struct perf_task_event
{
7005 struct task_struct
*task
;
7006 struct perf_event_context
*task_ctx
;
7009 struct perf_event_header header
;
7019 static int perf_event_task_match(struct perf_event
*event
)
7021 return event
->attr
.comm
|| event
->attr
.mmap
||
7022 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
7026 static void perf_event_task_output(struct perf_event
*event
,
7029 struct perf_task_event
*task_event
= data
;
7030 struct perf_output_handle handle
;
7031 struct perf_sample_data sample
;
7032 struct task_struct
*task
= task_event
->task
;
7033 int ret
, size
= task_event
->event_id
.header
.size
;
7035 if (!perf_event_task_match(event
))
7038 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
7040 ret
= perf_output_begin(&handle
, event
,
7041 task_event
->event_id
.header
.size
);
7045 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
7046 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
7048 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
7049 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
7051 task_event
->event_id
.time
= perf_event_clock(event
);
7053 perf_output_put(&handle
, task_event
->event_id
);
7055 perf_event__output_id_sample(event
, &handle
, &sample
);
7057 perf_output_end(&handle
);
7059 task_event
->event_id
.header
.size
= size
;
7062 static void perf_event_task(struct task_struct
*task
,
7063 struct perf_event_context
*task_ctx
,
7066 struct perf_task_event task_event
;
7068 if (!atomic_read(&nr_comm_events
) &&
7069 !atomic_read(&nr_mmap_events
) &&
7070 !atomic_read(&nr_task_events
))
7073 task_event
= (struct perf_task_event
){
7075 .task_ctx
= task_ctx
,
7078 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
7080 .size
= sizeof(task_event
.event_id
),
7090 perf_iterate_sb(perf_event_task_output
,
7095 void perf_event_fork(struct task_struct
*task
)
7097 perf_event_task(task
, NULL
, 1);
7098 perf_event_namespaces(task
);
7105 struct perf_comm_event
{
7106 struct task_struct
*task
;
7111 struct perf_event_header header
;
7118 static int perf_event_comm_match(struct perf_event
*event
)
7120 return event
->attr
.comm
;
7123 static void perf_event_comm_output(struct perf_event
*event
,
7126 struct perf_comm_event
*comm_event
= data
;
7127 struct perf_output_handle handle
;
7128 struct perf_sample_data sample
;
7129 int size
= comm_event
->event_id
.header
.size
;
7132 if (!perf_event_comm_match(event
))
7135 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
7136 ret
= perf_output_begin(&handle
, event
,
7137 comm_event
->event_id
.header
.size
);
7142 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
7143 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
7145 perf_output_put(&handle
, comm_event
->event_id
);
7146 __output_copy(&handle
, comm_event
->comm
,
7147 comm_event
->comm_size
);
7149 perf_event__output_id_sample(event
, &handle
, &sample
);
7151 perf_output_end(&handle
);
7153 comm_event
->event_id
.header
.size
= size
;
7156 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
7158 char comm
[TASK_COMM_LEN
];
7161 memset(comm
, 0, sizeof(comm
));
7162 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
7163 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
7165 comm_event
->comm
= comm
;
7166 comm_event
->comm_size
= size
;
7168 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
7170 perf_iterate_sb(perf_event_comm_output
,
7175 void perf_event_comm(struct task_struct
*task
, bool exec
)
7177 struct perf_comm_event comm_event
;
7179 if (!atomic_read(&nr_comm_events
))
7182 comm_event
= (struct perf_comm_event
){
7188 .type
= PERF_RECORD_COMM
,
7189 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
7197 perf_event_comm_event(&comm_event
);
7201 * namespaces tracking
7204 struct perf_namespaces_event
{
7205 struct task_struct
*task
;
7208 struct perf_event_header header
;
7213 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
7217 static int perf_event_namespaces_match(struct perf_event
*event
)
7219 return event
->attr
.namespaces
;
7222 static void perf_event_namespaces_output(struct perf_event
*event
,
7225 struct perf_namespaces_event
*namespaces_event
= data
;
7226 struct perf_output_handle handle
;
7227 struct perf_sample_data sample
;
7228 u16 header_size
= namespaces_event
->event_id
.header
.size
;
7231 if (!perf_event_namespaces_match(event
))
7234 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
7236 ret
= perf_output_begin(&handle
, event
,
7237 namespaces_event
->event_id
.header
.size
);
7241 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
7242 namespaces_event
->task
);
7243 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
7244 namespaces_event
->task
);
7246 perf_output_put(&handle
, namespaces_event
->event_id
);
7248 perf_event__output_id_sample(event
, &handle
, &sample
);
7250 perf_output_end(&handle
);
7252 namespaces_event
->event_id
.header
.size
= header_size
;
7255 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
7256 struct task_struct
*task
,
7257 const struct proc_ns_operations
*ns_ops
)
7259 struct path ns_path
;
7260 struct inode
*ns_inode
;
7263 error
= ns_get_path(&ns_path
, task
, ns_ops
);
7265 ns_inode
= ns_path
.dentry
->d_inode
;
7266 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
7267 ns_link_info
->ino
= ns_inode
->i_ino
;
7272 void perf_event_namespaces(struct task_struct
*task
)
7274 struct perf_namespaces_event namespaces_event
;
7275 struct perf_ns_link_info
*ns_link_info
;
7277 if (!atomic_read(&nr_namespaces_events
))
7280 namespaces_event
= (struct perf_namespaces_event
){
7284 .type
= PERF_RECORD_NAMESPACES
,
7286 .size
= sizeof(namespaces_event
.event_id
),
7290 .nr_namespaces
= NR_NAMESPACES
,
7291 /* .link_info[NR_NAMESPACES] */
7295 ns_link_info
= namespaces_event
.event_id
.link_info
;
7297 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
7298 task
, &mntns_operations
);
7300 #ifdef CONFIG_USER_NS
7301 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
7302 task
, &userns_operations
);
7304 #ifdef CONFIG_NET_NS
7305 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
7306 task
, &netns_operations
);
7308 #ifdef CONFIG_UTS_NS
7309 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
7310 task
, &utsns_operations
);
7312 #ifdef CONFIG_IPC_NS
7313 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
7314 task
, &ipcns_operations
);
7316 #ifdef CONFIG_PID_NS
7317 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
7318 task
, &pidns_operations
);
7320 #ifdef CONFIG_CGROUPS
7321 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
7322 task
, &cgroupns_operations
);
7325 perf_iterate_sb(perf_event_namespaces_output
,
7334 struct perf_mmap_event
{
7335 struct vm_area_struct
*vma
;
7337 const char *file_name
;
7345 struct perf_event_header header
;
7355 static int perf_event_mmap_match(struct perf_event
*event
,
7358 struct perf_mmap_event
*mmap_event
= data
;
7359 struct vm_area_struct
*vma
= mmap_event
->vma
;
7360 int executable
= vma
->vm_flags
& VM_EXEC
;
7362 return (!executable
&& event
->attr
.mmap_data
) ||
7363 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
7366 static void perf_event_mmap_output(struct perf_event
*event
,
7369 struct perf_mmap_event
*mmap_event
= data
;
7370 struct perf_output_handle handle
;
7371 struct perf_sample_data sample
;
7372 int size
= mmap_event
->event_id
.header
.size
;
7373 u32 type
= mmap_event
->event_id
.header
.type
;
7376 if (!perf_event_mmap_match(event
, data
))
7379 if (event
->attr
.mmap2
) {
7380 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
7381 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
7382 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
7383 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
7384 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
7385 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
7386 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
7389 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
7390 ret
= perf_output_begin(&handle
, event
,
7391 mmap_event
->event_id
.header
.size
);
7395 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
7396 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
7398 perf_output_put(&handle
, mmap_event
->event_id
);
7400 if (event
->attr
.mmap2
) {
7401 perf_output_put(&handle
, mmap_event
->maj
);
7402 perf_output_put(&handle
, mmap_event
->min
);
7403 perf_output_put(&handle
, mmap_event
->ino
);
7404 perf_output_put(&handle
, mmap_event
->ino_generation
);
7405 perf_output_put(&handle
, mmap_event
->prot
);
7406 perf_output_put(&handle
, mmap_event
->flags
);
7409 __output_copy(&handle
, mmap_event
->file_name
,
7410 mmap_event
->file_size
);
7412 perf_event__output_id_sample(event
, &handle
, &sample
);
7414 perf_output_end(&handle
);
7416 mmap_event
->event_id
.header
.size
= size
;
7417 mmap_event
->event_id
.header
.type
= type
;
7420 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
7422 struct vm_area_struct
*vma
= mmap_event
->vma
;
7423 struct file
*file
= vma
->vm_file
;
7424 int maj
= 0, min
= 0;
7425 u64 ino
= 0, gen
= 0;
7426 u32 prot
= 0, flags
= 0;
7432 if (vma
->vm_flags
& VM_READ
)
7434 if (vma
->vm_flags
& VM_WRITE
)
7436 if (vma
->vm_flags
& VM_EXEC
)
7439 if (vma
->vm_flags
& VM_MAYSHARE
)
7442 flags
= MAP_PRIVATE
;
7444 if (vma
->vm_flags
& VM_DENYWRITE
)
7445 flags
|= MAP_DENYWRITE
;
7446 if (vma
->vm_flags
& VM_MAYEXEC
)
7447 flags
|= MAP_EXECUTABLE
;
7448 if (vma
->vm_flags
& VM_LOCKED
)
7449 flags
|= MAP_LOCKED
;
7450 if (vma
->vm_flags
& VM_HUGETLB
)
7451 flags
|= MAP_HUGETLB
;
7454 struct inode
*inode
;
7457 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
7463 * d_path() works from the end of the rb backwards, so we
7464 * need to add enough zero bytes after the string to handle
7465 * the 64bit alignment we do later.
7467 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
7472 inode
= file_inode(vma
->vm_file
);
7473 dev
= inode
->i_sb
->s_dev
;
7475 gen
= inode
->i_generation
;
7481 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
7482 name
= (char *) vma
->vm_ops
->name(vma
);
7487 name
= (char *)arch_vma_name(vma
);
7491 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
7492 vma
->vm_end
>= vma
->vm_mm
->brk
) {
7496 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
7497 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
7507 strlcpy(tmp
, name
, sizeof(tmp
));
7511 * Since our buffer works in 8 byte units we need to align our string
7512 * size to a multiple of 8. However, we must guarantee the tail end is
7513 * zero'd out to avoid leaking random bits to userspace.
7515 size
= strlen(name
)+1;
7516 while (!IS_ALIGNED(size
, sizeof(u64
)))
7517 name
[size
++] = '\0';
7519 mmap_event
->file_name
= name
;
7520 mmap_event
->file_size
= size
;
7521 mmap_event
->maj
= maj
;
7522 mmap_event
->min
= min
;
7523 mmap_event
->ino
= ino
;
7524 mmap_event
->ino_generation
= gen
;
7525 mmap_event
->prot
= prot
;
7526 mmap_event
->flags
= flags
;
7528 if (!(vma
->vm_flags
& VM_EXEC
))
7529 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
7531 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
7533 perf_iterate_sb(perf_event_mmap_output
,
7541 * Check whether inode and address range match filter criteria.
7543 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
7544 struct file
*file
, unsigned long offset
,
7547 /* d_inode(NULL) won't be equal to any mapped user-space file */
7548 if (!filter
->path
.dentry
)
7551 if (d_inode(filter
->path
.dentry
) != file_inode(file
))
7554 if (filter
->offset
> offset
+ size
)
7557 if (filter
->offset
+ filter
->size
< offset
)
7563 static bool perf_addr_filter_vma_adjust(struct perf_addr_filter
*filter
,
7564 struct vm_area_struct
*vma
,
7565 struct perf_addr_filter_range
*fr
)
7567 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
7568 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
7569 struct file
*file
= vma
->vm_file
;
7571 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
7574 if (filter
->offset
< off
) {
7575 fr
->start
= vma
->vm_start
;
7576 fr
->size
= min(vma_size
, filter
->size
- (off
- filter
->offset
));
7578 fr
->start
= vma
->vm_start
+ filter
->offset
- off
;
7579 fr
->size
= min(vma
->vm_end
- fr
->start
, filter
->size
);
7585 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7587 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7588 struct vm_area_struct
*vma
= data
;
7589 struct perf_addr_filter
*filter
;
7590 unsigned int restart
= 0, count
= 0;
7591 unsigned long flags
;
7593 if (!has_addr_filter(event
))
7599 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7600 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7601 if (perf_addr_filter_vma_adjust(filter
, vma
,
7602 &event
->addr_filter_ranges
[count
]))
7609 event
->addr_filters_gen
++;
7610 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7613 perf_event_stop(event
, 1);
7617 * Adjust all task's events' filters to the new vma
7619 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7621 struct perf_event_context
*ctx
;
7625 * Data tracing isn't supported yet and as such there is no need
7626 * to keep track of anything that isn't related to executable code:
7628 if (!(vma
->vm_flags
& VM_EXEC
))
7632 for_each_task_context_nr(ctxn
) {
7633 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7637 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7642 void perf_event_mmap(struct vm_area_struct
*vma
)
7644 struct perf_mmap_event mmap_event
;
7646 if (!atomic_read(&nr_mmap_events
))
7649 mmap_event
= (struct perf_mmap_event
){
7655 .type
= PERF_RECORD_MMAP
,
7656 .misc
= PERF_RECORD_MISC_USER
,
7661 .start
= vma
->vm_start
,
7662 .len
= vma
->vm_end
- vma
->vm_start
,
7663 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7665 /* .maj (attr_mmap2 only) */
7666 /* .min (attr_mmap2 only) */
7667 /* .ino (attr_mmap2 only) */
7668 /* .ino_generation (attr_mmap2 only) */
7669 /* .prot (attr_mmap2 only) */
7670 /* .flags (attr_mmap2 only) */
7673 perf_addr_filters_adjust(vma
);
7674 perf_event_mmap_event(&mmap_event
);
7677 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7678 unsigned long size
, u64 flags
)
7680 struct perf_output_handle handle
;
7681 struct perf_sample_data sample
;
7682 struct perf_aux_event
{
7683 struct perf_event_header header
;
7689 .type
= PERF_RECORD_AUX
,
7691 .size
= sizeof(rec
),
7699 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7700 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7705 perf_output_put(&handle
, rec
);
7706 perf_event__output_id_sample(event
, &handle
, &sample
);
7708 perf_output_end(&handle
);
7712 * Lost/dropped samples logging
7714 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7716 struct perf_output_handle handle
;
7717 struct perf_sample_data sample
;
7721 struct perf_event_header header
;
7723 } lost_samples_event
= {
7725 .type
= PERF_RECORD_LOST_SAMPLES
,
7727 .size
= sizeof(lost_samples_event
),
7732 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7734 ret
= perf_output_begin(&handle
, event
,
7735 lost_samples_event
.header
.size
);
7739 perf_output_put(&handle
, lost_samples_event
);
7740 perf_event__output_id_sample(event
, &handle
, &sample
);
7741 perf_output_end(&handle
);
7745 * context_switch tracking
7748 struct perf_switch_event
{
7749 struct task_struct
*task
;
7750 struct task_struct
*next_prev
;
7753 struct perf_event_header header
;
7759 static int perf_event_switch_match(struct perf_event
*event
)
7761 return event
->attr
.context_switch
;
7764 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7766 struct perf_switch_event
*se
= data
;
7767 struct perf_output_handle handle
;
7768 struct perf_sample_data sample
;
7771 if (!perf_event_switch_match(event
))
7774 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7775 if (event
->ctx
->task
) {
7776 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7777 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7779 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7780 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7781 se
->event_id
.next_prev_pid
=
7782 perf_event_pid(event
, se
->next_prev
);
7783 se
->event_id
.next_prev_tid
=
7784 perf_event_tid(event
, se
->next_prev
);
7787 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7789 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7793 if (event
->ctx
->task
)
7794 perf_output_put(&handle
, se
->event_id
.header
);
7796 perf_output_put(&handle
, se
->event_id
);
7798 perf_event__output_id_sample(event
, &handle
, &sample
);
7800 perf_output_end(&handle
);
7803 static void perf_event_switch(struct task_struct
*task
,
7804 struct task_struct
*next_prev
, bool sched_in
)
7806 struct perf_switch_event switch_event
;
7808 /* N.B. caller checks nr_switch_events != 0 */
7810 switch_event
= (struct perf_switch_event
){
7812 .next_prev
= next_prev
,
7816 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7819 /* .next_prev_pid */
7820 /* .next_prev_tid */
7824 if (!sched_in
&& task
->state
== TASK_RUNNING
)
7825 switch_event
.event_id
.header
.misc
|=
7826 PERF_RECORD_MISC_SWITCH_OUT_PREEMPT
;
7828 perf_iterate_sb(perf_event_switch_output
,
7834 * IRQ throttle logging
7837 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7839 struct perf_output_handle handle
;
7840 struct perf_sample_data sample
;
7844 struct perf_event_header header
;
7848 } throttle_event
= {
7850 .type
= PERF_RECORD_THROTTLE
,
7852 .size
= sizeof(throttle_event
),
7854 .time
= perf_event_clock(event
),
7855 .id
= primary_event_id(event
),
7856 .stream_id
= event
->id
,
7860 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7862 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7864 ret
= perf_output_begin(&handle
, event
,
7865 throttle_event
.header
.size
);
7869 perf_output_put(&handle
, throttle_event
);
7870 perf_event__output_id_sample(event
, &handle
, &sample
);
7871 perf_output_end(&handle
);
7875 * ksymbol register/unregister tracking
7878 struct perf_ksymbol_event
{
7882 struct perf_event_header header
;
7890 static int perf_event_ksymbol_match(struct perf_event
*event
)
7892 return event
->attr
.ksymbol
;
7895 static void perf_event_ksymbol_output(struct perf_event
*event
, void *data
)
7897 struct perf_ksymbol_event
*ksymbol_event
= data
;
7898 struct perf_output_handle handle
;
7899 struct perf_sample_data sample
;
7902 if (!perf_event_ksymbol_match(event
))
7905 perf_event_header__init_id(&ksymbol_event
->event_id
.header
,
7907 ret
= perf_output_begin(&handle
, event
,
7908 ksymbol_event
->event_id
.header
.size
);
7912 perf_output_put(&handle
, ksymbol_event
->event_id
);
7913 __output_copy(&handle
, ksymbol_event
->name
, ksymbol_event
->name_len
);
7914 perf_event__output_id_sample(event
, &handle
, &sample
);
7916 perf_output_end(&handle
);
7919 void perf_event_ksymbol(u16 ksym_type
, u64 addr
, u32 len
, bool unregister
,
7922 struct perf_ksymbol_event ksymbol_event
;
7923 char name
[KSYM_NAME_LEN
];
7927 if (!atomic_read(&nr_ksymbol_events
))
7930 if (ksym_type
>= PERF_RECORD_KSYMBOL_TYPE_MAX
||
7931 ksym_type
== PERF_RECORD_KSYMBOL_TYPE_UNKNOWN
)
7934 strlcpy(name
, sym
, KSYM_NAME_LEN
);
7935 name_len
= strlen(name
) + 1;
7936 while (!IS_ALIGNED(name_len
, sizeof(u64
)))
7937 name
[name_len
++] = '\0';
7938 BUILD_BUG_ON(KSYM_NAME_LEN
% sizeof(u64
));
7941 flags
|= PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER
;
7943 ksymbol_event
= (struct perf_ksymbol_event
){
7945 .name_len
= name_len
,
7948 .type
= PERF_RECORD_KSYMBOL
,
7949 .size
= sizeof(ksymbol_event
.event_id
) +
7954 .ksym_type
= ksym_type
,
7959 perf_iterate_sb(perf_event_ksymbol_output
, &ksymbol_event
, NULL
);
7962 WARN_ONCE(1, "%s: Invalid KSYMBOL type 0x%x\n", __func__
, ksym_type
);
7966 * bpf program load/unload tracking
7969 struct perf_bpf_event
{
7970 struct bpf_prog
*prog
;
7972 struct perf_event_header header
;
7976 u8 tag
[BPF_TAG_SIZE
];
7980 static int perf_event_bpf_match(struct perf_event
*event
)
7982 return event
->attr
.bpf_event
;
7985 static void perf_event_bpf_output(struct perf_event
*event
, void *data
)
7987 struct perf_bpf_event
*bpf_event
= data
;
7988 struct perf_output_handle handle
;
7989 struct perf_sample_data sample
;
7992 if (!perf_event_bpf_match(event
))
7995 perf_event_header__init_id(&bpf_event
->event_id
.header
,
7997 ret
= perf_output_begin(&handle
, event
,
7998 bpf_event
->event_id
.header
.size
);
8002 perf_output_put(&handle
, bpf_event
->event_id
);
8003 perf_event__output_id_sample(event
, &handle
, &sample
);
8005 perf_output_end(&handle
);
8008 static void perf_event_bpf_emit_ksymbols(struct bpf_prog
*prog
,
8009 enum perf_bpf_event_type type
)
8011 bool unregister
= type
== PERF_BPF_EVENT_PROG_UNLOAD
;
8012 char sym
[KSYM_NAME_LEN
];
8015 if (prog
->aux
->func_cnt
== 0) {
8016 bpf_get_prog_name(prog
, sym
);
8017 perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF
,
8018 (u64
)(unsigned long)prog
->bpf_func
,
8019 prog
->jited_len
, unregister
, sym
);
8021 for (i
= 0; i
< prog
->aux
->func_cnt
; i
++) {
8022 struct bpf_prog
*subprog
= prog
->aux
->func
[i
];
8024 bpf_get_prog_name(subprog
, sym
);
8026 PERF_RECORD_KSYMBOL_TYPE_BPF
,
8027 (u64
)(unsigned long)subprog
->bpf_func
,
8028 subprog
->jited_len
, unregister
, sym
);
8033 void perf_event_bpf_event(struct bpf_prog
*prog
,
8034 enum perf_bpf_event_type type
,
8037 struct perf_bpf_event bpf_event
;
8039 if (type
<= PERF_BPF_EVENT_UNKNOWN
||
8040 type
>= PERF_BPF_EVENT_MAX
)
8044 case PERF_BPF_EVENT_PROG_LOAD
:
8045 case PERF_BPF_EVENT_PROG_UNLOAD
:
8046 if (atomic_read(&nr_ksymbol_events
))
8047 perf_event_bpf_emit_ksymbols(prog
, type
);
8053 if (!atomic_read(&nr_bpf_events
))
8056 bpf_event
= (struct perf_bpf_event
){
8060 .type
= PERF_RECORD_BPF_EVENT
,
8061 .size
= sizeof(bpf_event
.event_id
),
8065 .id
= prog
->aux
->id
,
8069 BUILD_BUG_ON(BPF_TAG_SIZE
% sizeof(u64
));
8071 memcpy(bpf_event
.event_id
.tag
, prog
->tag
, BPF_TAG_SIZE
);
8072 perf_iterate_sb(perf_event_bpf_output
, &bpf_event
, NULL
);
8075 void perf_event_itrace_started(struct perf_event
*event
)
8077 event
->attach_state
|= PERF_ATTACH_ITRACE
;
8080 static void perf_log_itrace_start(struct perf_event
*event
)
8082 struct perf_output_handle handle
;
8083 struct perf_sample_data sample
;
8084 struct perf_aux_event
{
8085 struct perf_event_header header
;
8092 event
= event
->parent
;
8094 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
8095 event
->attach_state
& PERF_ATTACH_ITRACE
)
8098 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
8099 rec
.header
.misc
= 0;
8100 rec
.header
.size
= sizeof(rec
);
8101 rec
.pid
= perf_event_pid(event
, current
);
8102 rec
.tid
= perf_event_tid(event
, current
);
8104 perf_event_header__init_id(&rec
.header
, &sample
, event
);
8105 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
8110 perf_output_put(&handle
, rec
);
8111 perf_event__output_id_sample(event
, &handle
, &sample
);
8113 perf_output_end(&handle
);
8117 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
8119 struct hw_perf_event
*hwc
= &event
->hw
;
8123 seq
= __this_cpu_read(perf_throttled_seq
);
8124 if (seq
!= hwc
->interrupts_seq
) {
8125 hwc
->interrupts_seq
= seq
;
8126 hwc
->interrupts
= 1;
8129 if (unlikely(throttle
8130 && hwc
->interrupts
>= max_samples_per_tick
)) {
8131 __this_cpu_inc(perf_throttled_count
);
8132 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
8133 hwc
->interrupts
= MAX_INTERRUPTS
;
8134 perf_log_throttle(event
, 0);
8139 if (event
->attr
.freq
) {
8140 u64 now
= perf_clock();
8141 s64 delta
= now
- hwc
->freq_time_stamp
;
8143 hwc
->freq_time_stamp
= now
;
8145 if (delta
> 0 && delta
< 2*TICK_NSEC
)
8146 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
8152 int perf_event_account_interrupt(struct perf_event
*event
)
8154 return __perf_event_account_interrupt(event
, 1);
8158 * Generic event overflow handling, sampling.
8161 static int __perf_event_overflow(struct perf_event
*event
,
8162 int throttle
, struct perf_sample_data
*data
,
8163 struct pt_regs
*regs
)
8165 int events
= atomic_read(&event
->event_limit
);
8169 * Non-sampling counters might still use the PMI to fold short
8170 * hardware counters, ignore those.
8172 if (unlikely(!is_sampling_event(event
)))
8175 ret
= __perf_event_account_interrupt(event
, throttle
);
8178 * XXX event_limit might not quite work as expected on inherited
8182 event
->pending_kill
= POLL_IN
;
8183 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
8185 event
->pending_kill
= POLL_HUP
;
8187 perf_event_disable_inatomic(event
);
8190 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
8192 if (*perf_event_fasync(event
) && event
->pending_kill
) {
8193 event
->pending_wakeup
= 1;
8194 irq_work_queue(&event
->pending
);
8200 int perf_event_overflow(struct perf_event
*event
,
8201 struct perf_sample_data
*data
,
8202 struct pt_regs
*regs
)
8204 return __perf_event_overflow(event
, 1, data
, regs
);
8208 * Generic software event infrastructure
8211 struct swevent_htable
{
8212 struct swevent_hlist
*swevent_hlist
;
8213 struct mutex hlist_mutex
;
8216 /* Recursion avoidance in each contexts */
8217 int recursion
[PERF_NR_CONTEXTS
];
8220 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
8223 * We directly increment event->count and keep a second value in
8224 * event->hw.period_left to count intervals. This period event
8225 * is kept in the range [-sample_period, 0] so that we can use the
8229 u64
perf_swevent_set_period(struct perf_event
*event
)
8231 struct hw_perf_event
*hwc
= &event
->hw
;
8232 u64 period
= hwc
->last_period
;
8236 hwc
->last_period
= hwc
->sample_period
;
8239 old
= val
= local64_read(&hwc
->period_left
);
8243 nr
= div64_u64(period
+ val
, period
);
8244 offset
= nr
* period
;
8246 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
8252 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
8253 struct perf_sample_data
*data
,
8254 struct pt_regs
*regs
)
8256 struct hw_perf_event
*hwc
= &event
->hw
;
8260 overflow
= perf_swevent_set_period(event
);
8262 if (hwc
->interrupts
== MAX_INTERRUPTS
)
8265 for (; overflow
; overflow
--) {
8266 if (__perf_event_overflow(event
, throttle
,
8269 * We inhibit the overflow from happening when
8270 * hwc->interrupts == MAX_INTERRUPTS.
8278 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
8279 struct perf_sample_data
*data
,
8280 struct pt_regs
*regs
)
8282 struct hw_perf_event
*hwc
= &event
->hw
;
8284 local64_add(nr
, &event
->count
);
8289 if (!is_sampling_event(event
))
8292 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
8294 return perf_swevent_overflow(event
, 1, data
, regs
);
8296 data
->period
= event
->hw
.last_period
;
8298 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
8299 return perf_swevent_overflow(event
, 1, data
, regs
);
8301 if (local64_add_negative(nr
, &hwc
->period_left
))
8304 perf_swevent_overflow(event
, 0, data
, regs
);
8307 static int perf_exclude_event(struct perf_event
*event
,
8308 struct pt_regs
*regs
)
8310 if (event
->hw
.state
& PERF_HES_STOPPED
)
8314 if (event
->attr
.exclude_user
&& user_mode(regs
))
8317 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
8324 static int perf_swevent_match(struct perf_event
*event
,
8325 enum perf_type_id type
,
8327 struct perf_sample_data
*data
,
8328 struct pt_regs
*regs
)
8330 if (event
->attr
.type
!= type
)
8333 if (event
->attr
.config
!= event_id
)
8336 if (perf_exclude_event(event
, regs
))
8342 static inline u64
swevent_hash(u64 type
, u32 event_id
)
8344 u64 val
= event_id
| (type
<< 32);
8346 return hash_64(val
, SWEVENT_HLIST_BITS
);
8349 static inline struct hlist_head
*
8350 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
8352 u64 hash
= swevent_hash(type
, event_id
);
8354 return &hlist
->heads
[hash
];
8357 /* For the read side: events when they trigger */
8358 static inline struct hlist_head
*
8359 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
8361 struct swevent_hlist
*hlist
;
8363 hlist
= rcu_dereference(swhash
->swevent_hlist
);
8367 return __find_swevent_head(hlist
, type
, event_id
);
8370 /* For the event head insertion and removal in the hlist */
8371 static inline struct hlist_head
*
8372 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
8374 struct swevent_hlist
*hlist
;
8375 u32 event_id
= event
->attr
.config
;
8376 u64 type
= event
->attr
.type
;
8379 * Event scheduling is always serialized against hlist allocation
8380 * and release. Which makes the protected version suitable here.
8381 * The context lock guarantees that.
8383 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
8384 lockdep_is_held(&event
->ctx
->lock
));
8388 return __find_swevent_head(hlist
, type
, event_id
);
8391 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
8393 struct perf_sample_data
*data
,
8394 struct pt_regs
*regs
)
8396 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8397 struct perf_event
*event
;
8398 struct hlist_head
*head
;
8401 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
8405 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8406 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
8407 perf_swevent_event(event
, nr
, data
, regs
);
8413 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
8415 int perf_swevent_get_recursion_context(void)
8417 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8419 return get_recursion_context(swhash
->recursion
);
8421 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
8423 void perf_swevent_put_recursion_context(int rctx
)
8425 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8427 put_recursion_context(swhash
->recursion
, rctx
);
8430 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8432 struct perf_sample_data data
;
8434 if (WARN_ON_ONCE(!regs
))
8437 perf_sample_data_init(&data
, addr
, 0);
8438 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
8441 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
8445 preempt_disable_notrace();
8446 rctx
= perf_swevent_get_recursion_context();
8447 if (unlikely(rctx
< 0))
8450 ___perf_sw_event(event_id
, nr
, regs
, addr
);
8452 perf_swevent_put_recursion_context(rctx
);
8454 preempt_enable_notrace();
8457 static void perf_swevent_read(struct perf_event
*event
)
8461 static int perf_swevent_add(struct perf_event
*event
, int flags
)
8463 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
8464 struct hw_perf_event
*hwc
= &event
->hw
;
8465 struct hlist_head
*head
;
8467 if (is_sampling_event(event
)) {
8468 hwc
->last_period
= hwc
->sample_period
;
8469 perf_swevent_set_period(event
);
8472 hwc
->state
= !(flags
& PERF_EF_START
);
8474 head
= find_swevent_head(swhash
, event
);
8475 if (WARN_ON_ONCE(!head
))
8478 hlist_add_head_rcu(&event
->hlist_entry
, head
);
8479 perf_event_update_userpage(event
);
8484 static void perf_swevent_del(struct perf_event
*event
, int flags
)
8486 hlist_del_rcu(&event
->hlist_entry
);
8489 static void perf_swevent_start(struct perf_event
*event
, int flags
)
8491 event
->hw
.state
= 0;
8494 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
8496 event
->hw
.state
= PERF_HES_STOPPED
;
8499 /* Deref the hlist from the update side */
8500 static inline struct swevent_hlist
*
8501 swevent_hlist_deref(struct swevent_htable
*swhash
)
8503 return rcu_dereference_protected(swhash
->swevent_hlist
,
8504 lockdep_is_held(&swhash
->hlist_mutex
));
8507 static void swevent_hlist_release(struct swevent_htable
*swhash
)
8509 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
8514 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
8515 kfree_rcu(hlist
, rcu_head
);
8518 static void swevent_hlist_put_cpu(int cpu
)
8520 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8522 mutex_lock(&swhash
->hlist_mutex
);
8524 if (!--swhash
->hlist_refcount
)
8525 swevent_hlist_release(swhash
);
8527 mutex_unlock(&swhash
->hlist_mutex
);
8530 static void swevent_hlist_put(void)
8534 for_each_possible_cpu(cpu
)
8535 swevent_hlist_put_cpu(cpu
);
8538 static int swevent_hlist_get_cpu(int cpu
)
8540 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8543 mutex_lock(&swhash
->hlist_mutex
);
8544 if (!swevent_hlist_deref(swhash
) &&
8545 cpumask_test_cpu(cpu
, perf_online_mask
)) {
8546 struct swevent_hlist
*hlist
;
8548 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
8553 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
8555 swhash
->hlist_refcount
++;
8557 mutex_unlock(&swhash
->hlist_mutex
);
8562 static int swevent_hlist_get(void)
8564 int err
, cpu
, failed_cpu
;
8566 mutex_lock(&pmus_lock
);
8567 for_each_possible_cpu(cpu
) {
8568 err
= swevent_hlist_get_cpu(cpu
);
8574 mutex_unlock(&pmus_lock
);
8577 for_each_possible_cpu(cpu
) {
8578 if (cpu
== failed_cpu
)
8580 swevent_hlist_put_cpu(cpu
);
8582 mutex_unlock(&pmus_lock
);
8586 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
8588 static void sw_perf_event_destroy(struct perf_event
*event
)
8590 u64 event_id
= event
->attr
.config
;
8592 WARN_ON(event
->parent
);
8594 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
8595 swevent_hlist_put();
8598 static int perf_swevent_init(struct perf_event
*event
)
8600 u64 event_id
= event
->attr
.config
;
8602 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8606 * no branch sampling for software events
8608 if (has_branch_stack(event
))
8612 case PERF_COUNT_SW_CPU_CLOCK
:
8613 case PERF_COUNT_SW_TASK_CLOCK
:
8620 if (event_id
>= PERF_COUNT_SW_MAX
)
8623 if (!event
->parent
) {
8626 err
= swevent_hlist_get();
8630 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
8631 event
->destroy
= sw_perf_event_destroy
;
8637 static struct pmu perf_swevent
= {
8638 .task_ctx_nr
= perf_sw_context
,
8640 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8642 .event_init
= perf_swevent_init
,
8643 .add
= perf_swevent_add
,
8644 .del
= perf_swevent_del
,
8645 .start
= perf_swevent_start
,
8646 .stop
= perf_swevent_stop
,
8647 .read
= perf_swevent_read
,
8650 #ifdef CONFIG_EVENT_TRACING
8652 static int perf_tp_filter_match(struct perf_event
*event
,
8653 struct perf_sample_data
*data
)
8655 void *record
= data
->raw
->frag
.data
;
8657 /* only top level events have filters set */
8659 event
= event
->parent
;
8661 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
8666 static int perf_tp_event_match(struct perf_event
*event
,
8667 struct perf_sample_data
*data
,
8668 struct pt_regs
*regs
)
8670 if (event
->hw
.state
& PERF_HES_STOPPED
)
8673 * If exclude_kernel, only trace user-space tracepoints (uprobes)
8675 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
8678 if (!perf_tp_filter_match(event
, data
))
8684 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
8685 struct trace_event_call
*call
, u64 count
,
8686 struct pt_regs
*regs
, struct hlist_head
*head
,
8687 struct task_struct
*task
)
8689 if (bpf_prog_array_valid(call
)) {
8690 *(struct pt_regs
**)raw_data
= regs
;
8691 if (!trace_call_bpf(call
, raw_data
) || hlist_empty(head
)) {
8692 perf_swevent_put_recursion_context(rctx
);
8696 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
8699 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
8701 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
8702 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
8703 struct task_struct
*task
)
8705 struct perf_sample_data data
;
8706 struct perf_event
*event
;
8708 struct perf_raw_record raw
= {
8715 perf_sample_data_init(&data
, 0, 0);
8718 perf_trace_buf_update(record
, event_type
);
8720 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8721 if (perf_tp_event_match(event
, &data
, regs
))
8722 perf_swevent_event(event
, count
, &data
, regs
);
8726 * If we got specified a target task, also iterate its context and
8727 * deliver this event there too.
8729 if (task
&& task
!= current
) {
8730 struct perf_event_context
*ctx
;
8731 struct trace_entry
*entry
= record
;
8734 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
8738 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
8739 if (event
->cpu
!= smp_processor_id())
8741 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8743 if (event
->attr
.config
!= entry
->type
)
8745 if (perf_tp_event_match(event
, &data
, regs
))
8746 perf_swevent_event(event
, count
, &data
, regs
);
8752 perf_swevent_put_recursion_context(rctx
);
8754 EXPORT_SYMBOL_GPL(perf_tp_event
);
8756 static void tp_perf_event_destroy(struct perf_event
*event
)
8758 perf_trace_destroy(event
);
8761 static int perf_tp_event_init(struct perf_event
*event
)
8765 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8769 * no branch sampling for tracepoint events
8771 if (has_branch_stack(event
))
8774 err
= perf_trace_init(event
);
8778 event
->destroy
= tp_perf_event_destroy
;
8783 static struct pmu perf_tracepoint
= {
8784 .task_ctx_nr
= perf_sw_context
,
8786 .event_init
= perf_tp_event_init
,
8787 .add
= perf_trace_add
,
8788 .del
= perf_trace_del
,
8789 .start
= perf_swevent_start
,
8790 .stop
= perf_swevent_stop
,
8791 .read
= perf_swevent_read
,
8794 #if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
8796 * Flags in config, used by dynamic PMU kprobe and uprobe
8797 * The flags should match following PMU_FORMAT_ATTR().
8799 * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
8800 * if not set, create kprobe/uprobe
8802 * The following values specify a reference counter (or semaphore in the
8803 * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
8804 * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
8806 * PERF_UPROBE_REF_CTR_OFFSET_BITS # of bits in config as th offset
8807 * PERF_UPROBE_REF_CTR_OFFSET_SHIFT # of bits to shift left
8809 enum perf_probe_config
{
8810 PERF_PROBE_CONFIG_IS_RETPROBE
= 1U << 0, /* [k,u]retprobe */
8811 PERF_UPROBE_REF_CTR_OFFSET_BITS
= 32,
8812 PERF_UPROBE_REF_CTR_OFFSET_SHIFT
= 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS
,
8815 PMU_FORMAT_ATTR(retprobe
, "config:0");
8818 #ifdef CONFIG_KPROBE_EVENTS
8819 static struct attribute
*kprobe_attrs
[] = {
8820 &format_attr_retprobe
.attr
,
8824 static struct attribute_group kprobe_format_group
= {
8826 .attrs
= kprobe_attrs
,
8829 static const struct attribute_group
*kprobe_attr_groups
[] = {
8830 &kprobe_format_group
,
8834 static int perf_kprobe_event_init(struct perf_event
*event
);
8835 static struct pmu perf_kprobe
= {
8836 .task_ctx_nr
= perf_sw_context
,
8837 .event_init
= perf_kprobe_event_init
,
8838 .add
= perf_trace_add
,
8839 .del
= perf_trace_del
,
8840 .start
= perf_swevent_start
,
8841 .stop
= perf_swevent_stop
,
8842 .read
= perf_swevent_read
,
8843 .attr_groups
= kprobe_attr_groups
,
8846 static int perf_kprobe_event_init(struct perf_event
*event
)
8851 if (event
->attr
.type
!= perf_kprobe
.type
)
8854 if (!capable(CAP_SYS_ADMIN
))
8858 * no branch sampling for probe events
8860 if (has_branch_stack(event
))
8863 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
8864 err
= perf_kprobe_init(event
, is_retprobe
);
8868 event
->destroy
= perf_kprobe_destroy
;
8872 #endif /* CONFIG_KPROBE_EVENTS */
8874 #ifdef CONFIG_UPROBE_EVENTS
8875 PMU_FORMAT_ATTR(ref_ctr_offset
, "config:32-63");
8877 static struct attribute
*uprobe_attrs
[] = {
8878 &format_attr_retprobe
.attr
,
8879 &format_attr_ref_ctr_offset
.attr
,
8883 static struct attribute_group uprobe_format_group
= {
8885 .attrs
= uprobe_attrs
,
8888 static const struct attribute_group
*uprobe_attr_groups
[] = {
8889 &uprobe_format_group
,
8893 static int perf_uprobe_event_init(struct perf_event
*event
);
8894 static struct pmu perf_uprobe
= {
8895 .task_ctx_nr
= perf_sw_context
,
8896 .event_init
= perf_uprobe_event_init
,
8897 .add
= perf_trace_add
,
8898 .del
= perf_trace_del
,
8899 .start
= perf_swevent_start
,
8900 .stop
= perf_swevent_stop
,
8901 .read
= perf_swevent_read
,
8902 .attr_groups
= uprobe_attr_groups
,
8905 static int perf_uprobe_event_init(struct perf_event
*event
)
8908 unsigned long ref_ctr_offset
;
8911 if (event
->attr
.type
!= perf_uprobe
.type
)
8914 if (!capable(CAP_SYS_ADMIN
))
8918 * no branch sampling for probe events
8920 if (has_branch_stack(event
))
8923 is_retprobe
= event
->attr
.config
& PERF_PROBE_CONFIG_IS_RETPROBE
;
8924 ref_ctr_offset
= event
->attr
.config
>> PERF_UPROBE_REF_CTR_OFFSET_SHIFT
;
8925 err
= perf_uprobe_init(event
, ref_ctr_offset
, is_retprobe
);
8929 event
->destroy
= perf_uprobe_destroy
;
8933 #endif /* CONFIG_UPROBE_EVENTS */
8935 static inline void perf_tp_register(void)
8937 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
8938 #ifdef CONFIG_KPROBE_EVENTS
8939 perf_pmu_register(&perf_kprobe
, "kprobe", -1);
8941 #ifdef CONFIG_UPROBE_EVENTS
8942 perf_pmu_register(&perf_uprobe
, "uprobe", -1);
8946 static void perf_event_free_filter(struct perf_event
*event
)
8948 ftrace_profile_free_filter(event
);
8951 #ifdef CONFIG_BPF_SYSCALL
8952 static void bpf_overflow_handler(struct perf_event
*event
,
8953 struct perf_sample_data
*data
,
8954 struct pt_regs
*regs
)
8956 struct bpf_perf_event_data_kern ctx
= {
8962 ctx
.regs
= perf_arch_bpf_user_pt_regs(regs
);
8964 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8967 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8970 __this_cpu_dec(bpf_prog_active
);
8975 event
->orig_overflow_handler(event
, data
, regs
);
8978 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8980 struct bpf_prog
*prog
;
8982 if (event
->overflow_handler_context
)
8983 /* hw breakpoint or kernel counter */
8989 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8991 return PTR_ERR(prog
);
8994 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8995 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8999 static void perf_event_free_bpf_handler(struct perf_event
*event
)
9001 struct bpf_prog
*prog
= event
->prog
;
9006 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
9011 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
9015 static void perf_event_free_bpf_handler(struct perf_event
*event
)
9021 * returns true if the event is a tracepoint, or a kprobe/upprobe created
9022 * with perf_event_open()
9024 static inline bool perf_event_is_tracing(struct perf_event
*event
)
9026 if (event
->pmu
== &perf_tracepoint
)
9028 #ifdef CONFIG_KPROBE_EVENTS
9029 if (event
->pmu
== &perf_kprobe
)
9032 #ifdef CONFIG_UPROBE_EVENTS
9033 if (event
->pmu
== &perf_uprobe
)
9039 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
9041 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
9042 struct bpf_prog
*prog
;
9045 if (!perf_event_is_tracing(event
))
9046 return perf_event_set_bpf_handler(event
, prog_fd
);
9048 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
9049 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
9050 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
9051 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
9052 /* bpf programs can only be attached to u/kprobe or tracepoint */
9055 prog
= bpf_prog_get(prog_fd
);
9057 return PTR_ERR(prog
);
9059 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
9060 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
9061 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
9062 /* valid fd, but invalid bpf program type */
9067 /* Kprobe override only works for kprobes, not uprobes. */
9068 if (prog
->kprobe_override
&&
9069 !(event
->tp_event
->flags
& TRACE_EVENT_FL_KPROBE
)) {
9074 if (is_tracepoint
|| is_syscall_tp
) {
9075 int off
= trace_event_get_offsets(event
->tp_event
);
9077 if (prog
->aux
->max_ctx_offset
> off
) {
9083 ret
= perf_event_attach_bpf_prog(event
, prog
);
9089 static void perf_event_free_bpf_prog(struct perf_event
*event
)
9091 if (!perf_event_is_tracing(event
)) {
9092 perf_event_free_bpf_handler(event
);
9095 perf_event_detach_bpf_prog(event
);
9100 static inline void perf_tp_register(void)
9104 static void perf_event_free_filter(struct perf_event
*event
)
9108 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
9113 static void perf_event_free_bpf_prog(struct perf_event
*event
)
9116 #endif /* CONFIG_EVENT_TRACING */
9118 #ifdef CONFIG_HAVE_HW_BREAKPOINT
9119 void perf_bp_event(struct perf_event
*bp
, void *data
)
9121 struct perf_sample_data sample
;
9122 struct pt_regs
*regs
= data
;
9124 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
9126 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
9127 perf_swevent_event(bp
, 1, &sample
, regs
);
9132 * Allocate a new address filter
9134 static struct perf_addr_filter
*
9135 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
9137 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
9138 struct perf_addr_filter
*filter
;
9140 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
9144 INIT_LIST_HEAD(&filter
->entry
);
9145 list_add_tail(&filter
->entry
, filters
);
9150 static void free_filters_list(struct list_head
*filters
)
9152 struct perf_addr_filter
*filter
, *iter
;
9154 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
9155 path_put(&filter
->path
);
9156 list_del(&filter
->entry
);
9162 * Free existing address filters and optionally install new ones
9164 static void perf_addr_filters_splice(struct perf_event
*event
,
9165 struct list_head
*head
)
9167 unsigned long flags
;
9170 if (!has_addr_filter(event
))
9173 /* don't bother with children, they don't have their own filters */
9177 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
9179 list_splice_init(&event
->addr_filters
.list
, &list
);
9181 list_splice(head
, &event
->addr_filters
.list
);
9183 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
9185 free_filters_list(&list
);
9189 * Scan through mm's vmas and see if one of them matches the
9190 * @filter; if so, adjust filter's address range.
9191 * Called with mm::mmap_sem down for reading.
9193 static void perf_addr_filter_apply(struct perf_addr_filter
*filter
,
9194 struct mm_struct
*mm
,
9195 struct perf_addr_filter_range
*fr
)
9197 struct vm_area_struct
*vma
;
9199 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
9203 if (perf_addr_filter_vma_adjust(filter
, vma
, fr
))
9209 * Update event's address range filters based on the
9210 * task's existing mappings, if any.
9212 static void perf_event_addr_filters_apply(struct perf_event
*event
)
9214 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
9215 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
9216 struct perf_addr_filter
*filter
;
9217 struct mm_struct
*mm
= NULL
;
9218 unsigned int count
= 0;
9219 unsigned long flags
;
9222 * We may observe TASK_TOMBSTONE, which means that the event tear-down
9223 * will stop on the parent's child_mutex that our caller is also holding
9225 if (task
== TASK_TOMBSTONE
)
9228 if (ifh
->nr_file_filters
) {
9229 mm
= get_task_mm(event
->ctx
->task
);
9233 down_read(&mm
->mmap_sem
);
9236 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
9237 list_for_each_entry(filter
, &ifh
->list
, entry
) {
9238 if (filter
->path
.dentry
) {
9240 * Adjust base offset if the filter is associated to a
9241 * binary that needs to be mapped:
9243 event
->addr_filter_ranges
[count
].start
= 0;
9244 event
->addr_filter_ranges
[count
].size
= 0;
9246 perf_addr_filter_apply(filter
, mm
, &event
->addr_filter_ranges
[count
]);
9248 event
->addr_filter_ranges
[count
].start
= filter
->offset
;
9249 event
->addr_filter_ranges
[count
].size
= filter
->size
;
9255 event
->addr_filters_gen
++;
9256 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
9258 if (ifh
->nr_file_filters
) {
9259 up_read(&mm
->mmap_sem
);
9265 perf_event_stop(event
, 1);
9269 * Address range filtering: limiting the data to certain
9270 * instruction address ranges. Filters are ioctl()ed to us from
9271 * userspace as ascii strings.
9273 * Filter string format:
9276 * where ACTION is one of the
9277 * * "filter": limit the trace to this region
9278 * * "start": start tracing from this address
9279 * * "stop": stop tracing at this address/region;
9281 * * for kernel addresses: <start address>[/<size>]
9282 * * for object files: <start address>[/<size>]@</path/to/object/file>
9284 * if <size> is not specified or is zero, the range is treated as a single
9285 * address; not valid for ACTION=="filter".
9299 IF_STATE_ACTION
= 0,
9304 static const match_table_t if_tokens
= {
9305 { IF_ACT_FILTER
, "filter" },
9306 { IF_ACT_START
, "start" },
9307 { IF_ACT_STOP
, "stop" },
9308 { IF_SRC_FILE
, "%u/%u@%s" },
9309 { IF_SRC_KERNEL
, "%u/%u" },
9310 { IF_SRC_FILEADDR
, "%u@%s" },
9311 { IF_SRC_KERNELADDR
, "%u" },
9312 { IF_ACT_NONE
, NULL
},
9316 * Address filter string parser
9319 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
9320 struct list_head
*filters
)
9322 struct perf_addr_filter
*filter
= NULL
;
9323 char *start
, *orig
, *filename
= NULL
;
9324 substring_t args
[MAX_OPT_ARGS
];
9325 int state
= IF_STATE_ACTION
, token
;
9326 unsigned int kernel
= 0;
9329 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
9333 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
9334 static const enum perf_addr_filter_action_t actions
[] = {
9335 [IF_ACT_FILTER
] = PERF_ADDR_FILTER_ACTION_FILTER
,
9336 [IF_ACT_START
] = PERF_ADDR_FILTER_ACTION_START
,
9337 [IF_ACT_STOP
] = PERF_ADDR_FILTER_ACTION_STOP
,
9344 /* filter definition begins */
9345 if (state
== IF_STATE_ACTION
) {
9346 filter
= perf_addr_filter_new(event
, filters
);
9351 token
= match_token(start
, if_tokens
, args
);
9356 if (state
!= IF_STATE_ACTION
)
9359 filter
->action
= actions
[token
];
9360 state
= IF_STATE_SOURCE
;
9363 case IF_SRC_KERNELADDR
:
9368 case IF_SRC_FILEADDR
:
9370 if (state
!= IF_STATE_SOURCE
)
9374 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
9378 if (token
== IF_SRC_KERNEL
|| token
== IF_SRC_FILE
) {
9380 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
9385 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
9386 int fpos
= token
== IF_SRC_FILE
? 2 : 1;
9388 filename
= match_strdup(&args
[fpos
]);
9395 state
= IF_STATE_END
;
9403 * Filter definition is fully parsed, validate and install it.
9404 * Make sure that it doesn't contradict itself or the event's
9407 if (state
== IF_STATE_END
) {
9409 if (kernel
&& event
->attr
.exclude_kernel
)
9413 * ACTION "filter" must have a non-zero length region
9416 if (filter
->action
== PERF_ADDR_FILTER_ACTION_FILTER
&&
9425 * For now, we only support file-based filters
9426 * in per-task events; doing so for CPU-wide
9427 * events requires additional context switching
9428 * trickery, since same object code will be
9429 * mapped at different virtual addresses in
9430 * different processes.
9433 if (!event
->ctx
->task
)
9434 goto fail_free_name
;
9436 /* look up the path and grab its inode */
9437 ret
= kern_path(filename
, LOOKUP_FOLLOW
,
9440 goto fail_free_name
;
9446 if (!filter
->path
.dentry
||
9447 !S_ISREG(d_inode(filter
->path
.dentry
)
9451 event
->addr_filters
.nr_file_filters
++;
9454 /* ready to consume more filters */
9455 state
= IF_STATE_ACTION
;
9460 if (state
!= IF_STATE_ACTION
)
9470 free_filters_list(filters
);
9477 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
9483 * Since this is called in perf_ioctl() path, we're already holding
9486 lockdep_assert_held(&event
->ctx
->mutex
);
9488 if (WARN_ON_ONCE(event
->parent
))
9491 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
9493 goto fail_clear_files
;
9495 ret
= event
->pmu
->addr_filters_validate(&filters
);
9497 goto fail_free_filters
;
9499 /* remove existing filters, if any */
9500 perf_addr_filters_splice(event
, &filters
);
9502 /* install new filters */
9503 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
9508 free_filters_list(&filters
);
9511 event
->addr_filters
.nr_file_filters
= 0;
9516 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
9521 filter_str
= strndup_user(arg
, PAGE_SIZE
);
9522 if (IS_ERR(filter_str
))
9523 return PTR_ERR(filter_str
);
9525 #ifdef CONFIG_EVENT_TRACING
9526 if (perf_event_is_tracing(event
)) {
9527 struct perf_event_context
*ctx
= event
->ctx
;
9530 * Beware, here be dragons!!
9532 * the tracepoint muck will deadlock against ctx->mutex, but
9533 * the tracepoint stuff does not actually need it. So
9534 * temporarily drop ctx->mutex. As per perf_event_ctx_lock() we
9535 * already have a reference on ctx.
9537 * This can result in event getting moved to a different ctx,
9538 * but that does not affect the tracepoint state.
9540 mutex_unlock(&ctx
->mutex
);
9541 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
9542 mutex_lock(&ctx
->mutex
);
9545 if (has_addr_filter(event
))
9546 ret
= perf_event_set_addr_filter(event
, filter_str
);
9553 * hrtimer based swevent callback
9556 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
9558 enum hrtimer_restart ret
= HRTIMER_RESTART
;
9559 struct perf_sample_data data
;
9560 struct pt_regs
*regs
;
9561 struct perf_event
*event
;
9564 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
9566 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
9567 return HRTIMER_NORESTART
;
9569 event
->pmu
->read(event
);
9571 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
9572 regs
= get_irq_regs();
9574 if (regs
&& !perf_exclude_event(event
, regs
)) {
9575 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
9576 if (__perf_event_overflow(event
, 1, &data
, regs
))
9577 ret
= HRTIMER_NORESTART
;
9580 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
9581 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
9586 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
9588 struct hw_perf_event
*hwc
= &event
->hw
;
9591 if (!is_sampling_event(event
))
9594 period
= local64_read(&hwc
->period_left
);
9599 local64_set(&hwc
->period_left
, 0);
9601 period
= max_t(u64
, 10000, hwc
->sample_period
);
9603 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
9604 HRTIMER_MODE_REL_PINNED_HARD
);
9607 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
9609 struct hw_perf_event
*hwc
= &event
->hw
;
9611 if (is_sampling_event(event
)) {
9612 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
9613 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
9615 hrtimer_cancel(&hwc
->hrtimer
);
9619 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
9621 struct hw_perf_event
*hwc
= &event
->hw
;
9623 if (!is_sampling_event(event
))
9626 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_HARD
);
9627 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
9630 * Since hrtimers have a fixed rate, we can do a static freq->period
9631 * mapping and avoid the whole period adjust feedback stuff.
9633 if (event
->attr
.freq
) {
9634 long freq
= event
->attr
.sample_freq
;
9636 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
9637 hwc
->sample_period
= event
->attr
.sample_period
;
9638 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9639 hwc
->last_period
= hwc
->sample_period
;
9640 event
->attr
.freq
= 0;
9645 * Software event: cpu wall time clock
9648 static void cpu_clock_event_update(struct perf_event
*event
)
9653 now
= local_clock();
9654 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
9655 local64_add(now
- prev
, &event
->count
);
9658 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
9660 local64_set(&event
->hw
.prev_count
, local_clock());
9661 perf_swevent_start_hrtimer(event
);
9664 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
9666 perf_swevent_cancel_hrtimer(event
);
9667 cpu_clock_event_update(event
);
9670 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
9672 if (flags
& PERF_EF_START
)
9673 cpu_clock_event_start(event
, flags
);
9674 perf_event_update_userpage(event
);
9679 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
9681 cpu_clock_event_stop(event
, flags
);
9684 static void cpu_clock_event_read(struct perf_event
*event
)
9686 cpu_clock_event_update(event
);
9689 static int cpu_clock_event_init(struct perf_event
*event
)
9691 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9694 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
9698 * no branch sampling for software events
9700 if (has_branch_stack(event
))
9703 perf_swevent_init_hrtimer(event
);
9708 static struct pmu perf_cpu_clock
= {
9709 .task_ctx_nr
= perf_sw_context
,
9711 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9713 .event_init
= cpu_clock_event_init
,
9714 .add
= cpu_clock_event_add
,
9715 .del
= cpu_clock_event_del
,
9716 .start
= cpu_clock_event_start
,
9717 .stop
= cpu_clock_event_stop
,
9718 .read
= cpu_clock_event_read
,
9722 * Software event: task time clock
9725 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
9730 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
9732 local64_add(delta
, &event
->count
);
9735 static void task_clock_event_start(struct perf_event
*event
, int flags
)
9737 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
9738 perf_swevent_start_hrtimer(event
);
9741 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
9743 perf_swevent_cancel_hrtimer(event
);
9744 task_clock_event_update(event
, event
->ctx
->time
);
9747 static int task_clock_event_add(struct perf_event
*event
, int flags
)
9749 if (flags
& PERF_EF_START
)
9750 task_clock_event_start(event
, flags
);
9751 perf_event_update_userpage(event
);
9756 static void task_clock_event_del(struct perf_event
*event
, int flags
)
9758 task_clock_event_stop(event
, PERF_EF_UPDATE
);
9761 static void task_clock_event_read(struct perf_event
*event
)
9763 u64 now
= perf_clock();
9764 u64 delta
= now
- event
->ctx
->timestamp
;
9765 u64 time
= event
->ctx
->time
+ delta
;
9767 task_clock_event_update(event
, time
);
9770 static int task_clock_event_init(struct perf_event
*event
)
9772 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
9775 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
9779 * no branch sampling for software events
9781 if (has_branch_stack(event
))
9784 perf_swevent_init_hrtimer(event
);
9789 static struct pmu perf_task_clock
= {
9790 .task_ctx_nr
= perf_sw_context
,
9792 .capabilities
= PERF_PMU_CAP_NO_NMI
,
9794 .event_init
= task_clock_event_init
,
9795 .add
= task_clock_event_add
,
9796 .del
= task_clock_event_del
,
9797 .start
= task_clock_event_start
,
9798 .stop
= task_clock_event_stop
,
9799 .read
= task_clock_event_read
,
9802 static void perf_pmu_nop_void(struct pmu
*pmu
)
9806 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
9810 static int perf_pmu_nop_int(struct pmu
*pmu
)
9815 static int perf_event_nop_int(struct perf_event
*event
, u64 value
)
9820 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
9822 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
9824 __this_cpu_write(nop_txn_flags
, flags
);
9826 if (flags
& ~PERF_PMU_TXN_ADD
)
9829 perf_pmu_disable(pmu
);
9832 static int perf_pmu_commit_txn(struct pmu
*pmu
)
9834 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
9836 __this_cpu_write(nop_txn_flags
, 0);
9838 if (flags
& ~PERF_PMU_TXN_ADD
)
9841 perf_pmu_enable(pmu
);
9845 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
9847 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
9849 __this_cpu_write(nop_txn_flags
, 0);
9851 if (flags
& ~PERF_PMU_TXN_ADD
)
9854 perf_pmu_enable(pmu
);
9857 static int perf_event_idx_default(struct perf_event
*event
)
9863 * Ensures all contexts with the same task_ctx_nr have the same
9864 * pmu_cpu_context too.
9866 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
9873 list_for_each_entry(pmu
, &pmus
, entry
) {
9874 if (pmu
->task_ctx_nr
== ctxn
)
9875 return pmu
->pmu_cpu_context
;
9881 static void free_pmu_context(struct pmu
*pmu
)
9884 * Static contexts such as perf_sw_context have a global lifetime
9885 * and may be shared between different PMUs. Avoid freeing them
9886 * when a single PMU is going away.
9888 if (pmu
->task_ctx_nr
> perf_invalid_context
)
9891 free_percpu(pmu
->pmu_cpu_context
);
9895 * Let userspace know that this PMU supports address range filtering:
9897 static ssize_t
nr_addr_filters_show(struct device
*dev
,
9898 struct device_attribute
*attr
,
9901 struct pmu
*pmu
= dev_get_drvdata(dev
);
9903 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
9905 DEVICE_ATTR_RO(nr_addr_filters
);
9907 static struct idr pmu_idr
;
9910 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
9912 struct pmu
*pmu
= dev_get_drvdata(dev
);
9914 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
9916 static DEVICE_ATTR_RO(type
);
9919 perf_event_mux_interval_ms_show(struct device
*dev
,
9920 struct device_attribute
*attr
,
9923 struct pmu
*pmu
= dev_get_drvdata(dev
);
9925 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
9928 static DEFINE_MUTEX(mux_interval_mutex
);
9931 perf_event_mux_interval_ms_store(struct device
*dev
,
9932 struct device_attribute
*attr
,
9933 const char *buf
, size_t count
)
9935 struct pmu
*pmu
= dev_get_drvdata(dev
);
9936 int timer
, cpu
, ret
;
9938 ret
= kstrtoint(buf
, 0, &timer
);
9945 /* same value, noting to do */
9946 if (timer
== pmu
->hrtimer_interval_ms
)
9949 mutex_lock(&mux_interval_mutex
);
9950 pmu
->hrtimer_interval_ms
= timer
;
9952 /* update all cpuctx for this PMU */
9954 for_each_online_cpu(cpu
) {
9955 struct perf_cpu_context
*cpuctx
;
9956 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9957 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
9959 cpu_function_call(cpu
,
9960 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
9963 mutex_unlock(&mux_interval_mutex
);
9967 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
9969 static struct attribute
*pmu_dev_attrs
[] = {
9970 &dev_attr_type
.attr
,
9971 &dev_attr_perf_event_mux_interval_ms
.attr
,
9974 ATTRIBUTE_GROUPS(pmu_dev
);
9976 static int pmu_bus_running
;
9977 static struct bus_type pmu_bus
= {
9978 .name
= "event_source",
9979 .dev_groups
= pmu_dev_groups
,
9982 static void pmu_dev_release(struct device
*dev
)
9987 static int pmu_dev_alloc(struct pmu
*pmu
)
9991 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9995 pmu
->dev
->groups
= pmu
->attr_groups
;
9996 device_initialize(pmu
->dev
);
9997 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
10001 dev_set_drvdata(pmu
->dev
, pmu
);
10002 pmu
->dev
->bus
= &pmu_bus
;
10003 pmu
->dev
->release
= pmu_dev_release
;
10004 ret
= device_add(pmu
->dev
);
10008 /* For PMUs with address filters, throw in an extra attribute: */
10009 if (pmu
->nr_addr_filters
)
10010 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
10015 if (pmu
->attr_update
)
10016 ret
= sysfs_update_groups(&pmu
->dev
->kobj
, pmu
->attr_update
);
10025 device_del(pmu
->dev
);
10028 put_device(pmu
->dev
);
10032 static struct lock_class_key cpuctx_mutex
;
10033 static struct lock_class_key cpuctx_lock
;
10035 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
10039 mutex_lock(&pmus_lock
);
10041 pmu
->pmu_disable_count
= alloc_percpu(int);
10042 if (!pmu
->pmu_disable_count
)
10051 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
10059 if (pmu_bus_running
) {
10060 ret
= pmu_dev_alloc(pmu
);
10066 if (pmu
->task_ctx_nr
== perf_hw_context
) {
10067 static int hw_context_taken
= 0;
10070 * Other than systems with heterogeneous CPUs, it never makes
10071 * sense for two PMUs to share perf_hw_context. PMUs which are
10072 * uncore must use perf_invalid_context.
10074 if (WARN_ON_ONCE(hw_context_taken
&&
10075 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
10076 pmu
->task_ctx_nr
= perf_invalid_context
;
10078 hw_context_taken
= 1;
10081 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
10082 if (pmu
->pmu_cpu_context
)
10083 goto got_cpu_context
;
10086 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
10087 if (!pmu
->pmu_cpu_context
)
10090 for_each_possible_cpu(cpu
) {
10091 struct perf_cpu_context
*cpuctx
;
10093 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
10094 __perf_event_init_context(&cpuctx
->ctx
);
10095 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
10096 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
10097 cpuctx
->ctx
.pmu
= pmu
;
10098 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
10100 __perf_mux_hrtimer_init(cpuctx
, cpu
);
10104 if (!pmu
->start_txn
) {
10105 if (pmu
->pmu_enable
) {
10107 * If we have pmu_enable/pmu_disable calls, install
10108 * transaction stubs that use that to try and batch
10109 * hardware accesses.
10111 pmu
->start_txn
= perf_pmu_start_txn
;
10112 pmu
->commit_txn
= perf_pmu_commit_txn
;
10113 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
10115 pmu
->start_txn
= perf_pmu_nop_txn
;
10116 pmu
->commit_txn
= perf_pmu_nop_int
;
10117 pmu
->cancel_txn
= perf_pmu_nop_void
;
10121 if (!pmu
->pmu_enable
) {
10122 pmu
->pmu_enable
= perf_pmu_nop_void
;
10123 pmu
->pmu_disable
= perf_pmu_nop_void
;
10126 if (!pmu
->check_period
)
10127 pmu
->check_period
= perf_event_nop_int
;
10129 if (!pmu
->event_idx
)
10130 pmu
->event_idx
= perf_event_idx_default
;
10132 list_add_rcu(&pmu
->entry
, &pmus
);
10133 atomic_set(&pmu
->exclusive_cnt
, 0);
10136 mutex_unlock(&pmus_lock
);
10141 device_del(pmu
->dev
);
10142 put_device(pmu
->dev
);
10145 if (pmu
->type
>= PERF_TYPE_MAX
)
10146 idr_remove(&pmu_idr
, pmu
->type
);
10149 free_percpu(pmu
->pmu_disable_count
);
10152 EXPORT_SYMBOL_GPL(perf_pmu_register
);
10154 void perf_pmu_unregister(struct pmu
*pmu
)
10156 mutex_lock(&pmus_lock
);
10157 list_del_rcu(&pmu
->entry
);
10160 * We dereference the pmu list under both SRCU and regular RCU, so
10161 * synchronize against both of those.
10163 synchronize_srcu(&pmus_srcu
);
10166 free_percpu(pmu
->pmu_disable_count
);
10167 if (pmu
->type
>= PERF_TYPE_MAX
)
10168 idr_remove(&pmu_idr
, pmu
->type
);
10169 if (pmu_bus_running
) {
10170 if (pmu
->nr_addr_filters
)
10171 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
10172 device_del(pmu
->dev
);
10173 put_device(pmu
->dev
);
10175 free_pmu_context(pmu
);
10176 mutex_unlock(&pmus_lock
);
10178 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
10180 static inline bool has_extended_regs(struct perf_event
*event
)
10182 return (event
->attr
.sample_regs_user
& PERF_REG_EXTENDED_MASK
) ||
10183 (event
->attr
.sample_regs_intr
& PERF_REG_EXTENDED_MASK
);
10186 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
10188 struct perf_event_context
*ctx
= NULL
;
10191 if (!try_module_get(pmu
->module
))
10195 * A number of pmu->event_init() methods iterate the sibling_list to,
10196 * for example, validate if the group fits on the PMU. Therefore,
10197 * if this is a sibling event, acquire the ctx->mutex to protect
10198 * the sibling_list.
10200 if (event
->group_leader
!= event
&& pmu
->task_ctx_nr
!= perf_sw_context
) {
10202 * This ctx->mutex can nest when we're called through
10203 * inheritance. See the perf_event_ctx_lock_nested() comment.
10205 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
10206 SINGLE_DEPTH_NESTING
);
10211 ret
= pmu
->event_init(event
);
10214 perf_event_ctx_unlock(event
->group_leader
, ctx
);
10217 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXTENDED_REGS
) &&
10218 has_extended_regs(event
))
10221 if (pmu
->capabilities
& PERF_PMU_CAP_NO_EXCLUDE
&&
10222 event_has_any_exclude_flag(event
))
10225 if (ret
&& event
->destroy
)
10226 event
->destroy(event
);
10230 module_put(pmu
->module
);
10235 static struct pmu
*perf_init_event(struct perf_event
*event
)
10241 idx
= srcu_read_lock(&pmus_srcu
);
10243 /* Try parent's PMU first: */
10244 if (event
->parent
&& event
->parent
->pmu
) {
10245 pmu
= event
->parent
->pmu
;
10246 ret
= perf_try_init_event(pmu
, event
);
10252 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
10255 ret
= perf_try_init_event(pmu
, event
);
10257 pmu
= ERR_PTR(ret
);
10261 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10262 ret
= perf_try_init_event(pmu
, event
);
10266 if (ret
!= -ENOENT
) {
10267 pmu
= ERR_PTR(ret
);
10271 pmu
= ERR_PTR(-ENOENT
);
10273 srcu_read_unlock(&pmus_srcu
, idx
);
10278 static void attach_sb_event(struct perf_event
*event
)
10280 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
10282 raw_spin_lock(&pel
->lock
);
10283 list_add_rcu(&event
->sb_list
, &pel
->list
);
10284 raw_spin_unlock(&pel
->lock
);
10288 * We keep a list of all !task (and therefore per-cpu) events
10289 * that need to receive side-band records.
10291 * This avoids having to scan all the various PMU per-cpu contexts
10292 * looking for them.
10294 static void account_pmu_sb_event(struct perf_event
*event
)
10296 if (is_sb_event(event
))
10297 attach_sb_event(event
);
10300 static void account_event_cpu(struct perf_event
*event
, int cpu
)
10305 if (is_cgroup_event(event
))
10306 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
10309 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
10310 static void account_freq_event_nohz(void)
10312 #ifdef CONFIG_NO_HZ_FULL
10313 /* Lock so we don't race with concurrent unaccount */
10314 spin_lock(&nr_freq_lock
);
10315 if (atomic_inc_return(&nr_freq_events
) == 1)
10316 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
10317 spin_unlock(&nr_freq_lock
);
10321 static void account_freq_event(void)
10323 if (tick_nohz_full_enabled())
10324 account_freq_event_nohz();
10326 atomic_inc(&nr_freq_events
);
10330 static void account_event(struct perf_event
*event
)
10337 if (event
->attach_state
& PERF_ATTACH_TASK
)
10339 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
10340 atomic_inc(&nr_mmap_events
);
10341 if (event
->attr
.comm
)
10342 atomic_inc(&nr_comm_events
);
10343 if (event
->attr
.namespaces
)
10344 atomic_inc(&nr_namespaces_events
);
10345 if (event
->attr
.task
)
10346 atomic_inc(&nr_task_events
);
10347 if (event
->attr
.freq
)
10348 account_freq_event();
10349 if (event
->attr
.context_switch
) {
10350 atomic_inc(&nr_switch_events
);
10353 if (has_branch_stack(event
))
10355 if (is_cgroup_event(event
))
10357 if (event
->attr
.ksymbol
)
10358 atomic_inc(&nr_ksymbol_events
);
10359 if (event
->attr
.bpf_event
)
10360 atomic_inc(&nr_bpf_events
);
10364 * We need the mutex here because static_branch_enable()
10365 * must complete *before* the perf_sched_count increment
10368 if (atomic_inc_not_zero(&perf_sched_count
))
10371 mutex_lock(&perf_sched_mutex
);
10372 if (!atomic_read(&perf_sched_count
)) {
10373 static_branch_enable(&perf_sched_events
);
10375 * Guarantee that all CPUs observe they key change and
10376 * call the perf scheduling hooks before proceeding to
10377 * install events that need them.
10382 * Now that we have waited for the sync_sched(), allow further
10383 * increments to by-pass the mutex.
10385 atomic_inc(&perf_sched_count
);
10386 mutex_unlock(&perf_sched_mutex
);
10390 account_event_cpu(event
, event
->cpu
);
10392 account_pmu_sb_event(event
);
10396 * Allocate and initialize an event structure
10398 static struct perf_event
*
10399 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
10400 struct task_struct
*task
,
10401 struct perf_event
*group_leader
,
10402 struct perf_event
*parent_event
,
10403 perf_overflow_handler_t overflow_handler
,
10404 void *context
, int cgroup_fd
)
10407 struct perf_event
*event
;
10408 struct hw_perf_event
*hwc
;
10409 long err
= -EINVAL
;
10411 if ((unsigned)cpu
>= nr_cpu_ids
) {
10412 if (!task
|| cpu
!= -1)
10413 return ERR_PTR(-EINVAL
);
10416 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
10418 return ERR_PTR(-ENOMEM
);
10421 * Single events are their own group leaders, with an
10422 * empty sibling list:
10425 group_leader
= event
;
10427 mutex_init(&event
->child_mutex
);
10428 INIT_LIST_HEAD(&event
->child_list
);
10430 INIT_LIST_HEAD(&event
->event_entry
);
10431 INIT_LIST_HEAD(&event
->sibling_list
);
10432 INIT_LIST_HEAD(&event
->active_list
);
10433 init_event_group(event
);
10434 INIT_LIST_HEAD(&event
->rb_entry
);
10435 INIT_LIST_HEAD(&event
->active_entry
);
10436 INIT_LIST_HEAD(&event
->addr_filters
.list
);
10437 INIT_HLIST_NODE(&event
->hlist_entry
);
10440 init_waitqueue_head(&event
->waitq
);
10441 event
->pending_disable
= -1;
10442 init_irq_work(&event
->pending
, perf_pending_event
);
10444 mutex_init(&event
->mmap_mutex
);
10445 raw_spin_lock_init(&event
->addr_filters
.lock
);
10447 atomic_long_set(&event
->refcount
, 1);
10449 event
->attr
= *attr
;
10450 event
->group_leader
= group_leader
;
10454 event
->parent
= parent_event
;
10456 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
10457 event
->id
= atomic64_inc_return(&perf_event_id
);
10459 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10462 event
->attach_state
= PERF_ATTACH_TASK
;
10464 * XXX pmu::event_init needs to know what task to account to
10465 * and we cannot use the ctx information because we need the
10466 * pmu before we get a ctx.
10468 event
->hw
.target
= get_task_struct(task
);
10471 event
->clock
= &local_clock
;
10473 event
->clock
= parent_event
->clock
;
10475 if (!overflow_handler
&& parent_event
) {
10476 overflow_handler
= parent_event
->overflow_handler
;
10477 context
= parent_event
->overflow_handler_context
;
10478 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
10479 if (overflow_handler
== bpf_overflow_handler
) {
10480 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
10482 if (IS_ERR(prog
)) {
10483 err
= PTR_ERR(prog
);
10486 event
->prog
= prog
;
10487 event
->orig_overflow_handler
=
10488 parent_event
->orig_overflow_handler
;
10493 if (overflow_handler
) {
10494 event
->overflow_handler
= overflow_handler
;
10495 event
->overflow_handler_context
= context
;
10496 } else if (is_write_backward(event
)){
10497 event
->overflow_handler
= perf_event_output_backward
;
10498 event
->overflow_handler_context
= NULL
;
10500 event
->overflow_handler
= perf_event_output_forward
;
10501 event
->overflow_handler_context
= NULL
;
10504 perf_event__state_init(event
);
10509 hwc
->sample_period
= attr
->sample_period
;
10510 if (attr
->freq
&& attr
->sample_freq
)
10511 hwc
->sample_period
= 1;
10512 hwc
->last_period
= hwc
->sample_period
;
10514 local64_set(&hwc
->period_left
, hwc
->sample_period
);
10517 * We currently do not support PERF_SAMPLE_READ on inherited events.
10518 * See perf_output_read().
10520 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
10523 if (!has_branch_stack(event
))
10524 event
->attr
.branch_sample_type
= 0;
10526 if (cgroup_fd
!= -1) {
10527 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
10532 pmu
= perf_init_event(event
);
10534 err
= PTR_ERR(pmu
);
10539 * Disallow uncore-cgroup events, they don't make sense as the cgroup will
10540 * be different on other CPUs in the uncore mask.
10542 if (pmu
->task_ctx_nr
== perf_invalid_context
&& cgroup_fd
!= -1) {
10547 if (event
->attr
.aux_output
&&
10548 !(pmu
->capabilities
& PERF_PMU_CAP_AUX_OUTPUT
)) {
10553 err
= exclusive_event_init(event
);
10557 if (has_addr_filter(event
)) {
10558 event
->addr_filter_ranges
= kcalloc(pmu
->nr_addr_filters
,
10559 sizeof(struct perf_addr_filter_range
),
10561 if (!event
->addr_filter_ranges
) {
10567 * Clone the parent's vma offsets: they are valid until exec()
10568 * even if the mm is not shared with the parent.
10570 if (event
->parent
) {
10571 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
10573 raw_spin_lock_irq(&ifh
->lock
);
10574 memcpy(event
->addr_filter_ranges
,
10575 event
->parent
->addr_filter_ranges
,
10576 pmu
->nr_addr_filters
* sizeof(struct perf_addr_filter_range
));
10577 raw_spin_unlock_irq(&ifh
->lock
);
10580 /* force hw sync on the address filters */
10581 event
->addr_filters_gen
= 1;
10584 if (!event
->parent
) {
10585 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
10586 err
= get_callchain_buffers(attr
->sample_max_stack
);
10588 goto err_addr_filters
;
10592 /* symmetric to unaccount_event() in _free_event() */
10593 account_event(event
);
10598 kfree(event
->addr_filter_ranges
);
10601 exclusive_event_destroy(event
);
10604 if (event
->destroy
)
10605 event
->destroy(event
);
10606 module_put(pmu
->module
);
10608 if (is_cgroup_event(event
))
10609 perf_detach_cgroup(event
);
10611 put_pid_ns(event
->ns
);
10612 if (event
->hw
.target
)
10613 put_task_struct(event
->hw
.target
);
10616 return ERR_PTR(err
);
10619 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
10620 struct perf_event_attr
*attr
)
10625 /* Zero the full structure, so that a short copy will be nice. */
10626 memset(attr
, 0, sizeof(*attr
));
10628 ret
= get_user(size
, &uattr
->size
);
10632 /* ABI compatibility quirk: */
10634 size
= PERF_ATTR_SIZE_VER0
;
10635 if (size
< PERF_ATTR_SIZE_VER0
|| size
> PAGE_SIZE
)
10638 ret
= copy_struct_from_user(attr
, sizeof(*attr
), uattr
, size
);
10647 if (attr
->__reserved_1
|| attr
->__reserved_2
)
10650 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
10653 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
10656 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
10657 u64 mask
= attr
->branch_sample_type
;
10659 /* only using defined bits */
10660 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
10663 /* at least one branch bit must be set */
10664 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
10667 /* propagate priv level, when not set for branch */
10668 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
10670 /* exclude_kernel checked on syscall entry */
10671 if (!attr
->exclude_kernel
)
10672 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
10674 if (!attr
->exclude_user
)
10675 mask
|= PERF_SAMPLE_BRANCH_USER
;
10677 if (!attr
->exclude_hv
)
10678 mask
|= PERF_SAMPLE_BRANCH_HV
;
10680 * adjust user setting (for HW filter setup)
10682 attr
->branch_sample_type
= mask
;
10684 /* privileged levels capture (kernel, hv): check permissions */
10685 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
10686 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10690 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
10691 ret
= perf_reg_validate(attr
->sample_regs_user
);
10696 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
10697 if (!arch_perf_have_user_stack_dump())
10701 * We have __u32 type for the size, but so far
10702 * we can only use __u16 as maximum due to the
10703 * __u16 sample size limit.
10705 if (attr
->sample_stack_user
>= USHRT_MAX
)
10707 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
10711 if (!attr
->sample_max_stack
)
10712 attr
->sample_max_stack
= sysctl_perf_event_max_stack
;
10714 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
10715 ret
= perf_reg_validate(attr
->sample_regs_intr
);
10720 put_user(sizeof(*attr
), &uattr
->size
);
10726 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
10728 struct ring_buffer
*rb
= NULL
;
10734 /* don't allow circular references */
10735 if (event
== output_event
)
10739 * Don't allow cross-cpu buffers
10741 if (output_event
->cpu
!= event
->cpu
)
10745 * If its not a per-cpu rb, it must be the same task.
10747 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
10751 * Mixing clocks in the same buffer is trouble you don't need.
10753 if (output_event
->clock
!= event
->clock
)
10757 * Either writing ring buffer from beginning or from end.
10758 * Mixing is not allowed.
10760 if (is_write_backward(output_event
) != is_write_backward(event
))
10764 * If both events generate aux data, they must be on the same PMU
10766 if (has_aux(event
) && has_aux(output_event
) &&
10767 event
->pmu
!= output_event
->pmu
)
10771 mutex_lock(&event
->mmap_mutex
);
10772 /* Can't redirect output if we've got an active mmap() */
10773 if (atomic_read(&event
->mmap_count
))
10776 if (output_event
) {
10777 /* get the rb we want to redirect to */
10778 rb
= ring_buffer_get(output_event
);
10783 ring_buffer_attach(event
, rb
);
10787 mutex_unlock(&event
->mmap_mutex
);
10793 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
10799 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
10802 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
10804 bool nmi_safe
= false;
10807 case CLOCK_MONOTONIC
:
10808 event
->clock
= &ktime_get_mono_fast_ns
;
10812 case CLOCK_MONOTONIC_RAW
:
10813 event
->clock
= &ktime_get_raw_fast_ns
;
10817 case CLOCK_REALTIME
:
10818 event
->clock
= &ktime_get_real_ns
;
10821 case CLOCK_BOOTTIME
:
10822 event
->clock
= &ktime_get_boottime_ns
;
10826 event
->clock
= &ktime_get_clocktai_ns
;
10833 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
10840 * Variation on perf_event_ctx_lock_nested(), except we take two context
10843 static struct perf_event_context
*
10844 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
10845 struct perf_event_context
*ctx
)
10847 struct perf_event_context
*gctx
;
10851 gctx
= READ_ONCE(group_leader
->ctx
);
10852 if (!refcount_inc_not_zero(&gctx
->refcount
)) {
10858 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
10860 if (group_leader
->ctx
!= gctx
) {
10861 mutex_unlock(&ctx
->mutex
);
10862 mutex_unlock(&gctx
->mutex
);
10871 * sys_perf_event_open - open a performance event, associate it to a task/cpu
10873 * @attr_uptr: event_id type attributes for monitoring/sampling
10876 * @group_fd: group leader event fd
10878 SYSCALL_DEFINE5(perf_event_open
,
10879 struct perf_event_attr __user
*, attr_uptr
,
10880 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
10882 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
10883 struct perf_event
*event
, *sibling
;
10884 struct perf_event_attr attr
;
10885 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
10886 struct file
*event_file
= NULL
;
10887 struct fd group
= {NULL
, 0};
10888 struct task_struct
*task
= NULL
;
10891 int move_group
= 0;
10893 int f_flags
= O_RDWR
;
10894 int cgroup_fd
= -1;
10896 /* for future expandability... */
10897 if (flags
& ~PERF_FLAG_ALL
)
10900 err
= perf_copy_attr(attr_uptr
, &attr
);
10904 if (!attr
.exclude_kernel
) {
10905 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10909 if (attr
.namespaces
) {
10910 if (!capable(CAP_SYS_ADMIN
))
10915 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
10918 if (attr
.sample_period
& (1ULL << 63))
10922 /* Only privileged users can get physical addresses */
10923 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
10924 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10927 err
= security_locked_down(LOCKDOWN_PERF
);
10928 if (err
&& (attr
.sample_type
& PERF_SAMPLE_REGS_INTR
))
10929 /* REGS_INTR can leak data, lockdown must prevent this */
10935 * In cgroup mode, the pid argument is used to pass the fd
10936 * opened to the cgroup directory in cgroupfs. The cpu argument
10937 * designates the cpu on which to monitor threads from that
10940 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
10943 if (flags
& PERF_FLAG_FD_CLOEXEC
)
10944 f_flags
|= O_CLOEXEC
;
10946 event_fd
= get_unused_fd_flags(f_flags
);
10950 if (group_fd
!= -1) {
10951 err
= perf_fget_light(group_fd
, &group
);
10954 group_leader
= group
.file
->private_data
;
10955 if (flags
& PERF_FLAG_FD_OUTPUT
)
10956 output_event
= group_leader
;
10957 if (flags
& PERF_FLAG_FD_NO_GROUP
)
10958 group_leader
= NULL
;
10961 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
10962 task
= find_lively_task_by_vpid(pid
);
10963 if (IS_ERR(task
)) {
10964 err
= PTR_ERR(task
);
10969 if (task
&& group_leader
&&
10970 group_leader
->attr
.inherit
!= attr
.inherit
) {
10976 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
10981 * Reuse ptrace permission checks for now.
10983 * We must hold cred_guard_mutex across this and any potential
10984 * perf_install_in_context() call for this new event to
10985 * serialize against exec() altering our credentials (and the
10986 * perf_event_exit_task() that could imply).
10989 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
10993 if (flags
& PERF_FLAG_PID_CGROUP
)
10996 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
10997 NULL
, NULL
, cgroup_fd
);
10998 if (IS_ERR(event
)) {
10999 err
= PTR_ERR(event
);
11003 if (is_sampling_event(event
)) {
11004 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
11011 * Special case software events and allow them to be part of
11012 * any hardware group.
11016 if (attr
.use_clockid
) {
11017 err
= perf_event_set_clock(event
, attr
.clockid
);
11022 if (pmu
->task_ctx_nr
== perf_sw_context
)
11023 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
11025 if (group_leader
) {
11026 if (is_software_event(event
) &&
11027 !in_software_context(group_leader
)) {
11029 * If the event is a sw event, but the group_leader
11030 * is on hw context.
11032 * Allow the addition of software events to hw
11033 * groups, this is safe because software events
11034 * never fail to schedule.
11036 pmu
= group_leader
->ctx
->pmu
;
11037 } else if (!is_software_event(event
) &&
11038 is_software_event(group_leader
) &&
11039 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
11041 * In case the group is a pure software group, and we
11042 * try to add a hardware event, move the whole group to
11043 * the hardware context.
11050 * Get the target context (task or percpu):
11052 ctx
= find_get_context(pmu
, task
, event
);
11054 err
= PTR_ERR(ctx
);
11059 * Look up the group leader (we will attach this event to it):
11061 if (group_leader
) {
11065 * Do not allow a recursive hierarchy (this new sibling
11066 * becoming part of another group-sibling):
11068 if (group_leader
->group_leader
!= group_leader
)
11071 /* All events in a group should have the same clock */
11072 if (group_leader
->clock
!= event
->clock
)
11076 * Make sure we're both events for the same CPU;
11077 * grouping events for different CPUs is broken; since
11078 * you can never concurrently schedule them anyhow.
11080 if (group_leader
->cpu
!= event
->cpu
)
11084 * Make sure we're both on the same task, or both
11087 if (group_leader
->ctx
->task
!= ctx
->task
)
11091 * Do not allow to attach to a group in a different task
11092 * or CPU context. If we're moving SW events, we'll fix
11093 * this up later, so allow that.
11095 if (!move_group
&& group_leader
->ctx
!= ctx
)
11099 * Only a group leader can be exclusive or pinned
11101 if (attr
.exclusive
|| attr
.pinned
)
11105 if (output_event
) {
11106 err
= perf_event_set_output(event
, output_event
);
11111 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
11113 if (IS_ERR(event_file
)) {
11114 err
= PTR_ERR(event_file
);
11120 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
11122 if (gctx
->task
== TASK_TOMBSTONE
) {
11128 * Check if we raced against another sys_perf_event_open() call
11129 * moving the software group underneath us.
11131 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
11133 * If someone moved the group out from under us, check
11134 * if this new event wound up on the same ctx, if so
11135 * its the regular !move_group case, otherwise fail.
11141 perf_event_ctx_unlock(group_leader
, gctx
);
11147 * Failure to create exclusive events returns -EBUSY.
11150 if (!exclusive_event_installable(group_leader
, ctx
))
11153 for_each_sibling_event(sibling
, group_leader
) {
11154 if (!exclusive_event_installable(sibling
, ctx
))
11158 mutex_lock(&ctx
->mutex
);
11161 if (ctx
->task
== TASK_TOMBSTONE
) {
11166 if (!perf_event_validate_size(event
)) {
11173 * Check if the @cpu we're creating an event for is online.
11175 * We use the perf_cpu_context::ctx::mutex to serialize against
11176 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
11178 struct perf_cpu_context
*cpuctx
=
11179 container_of(ctx
, struct perf_cpu_context
, ctx
);
11181 if (!cpuctx
->online
) {
11187 if (event
->attr
.aux_output
&& !perf_get_aux_event(event
, group_leader
))
11191 * Must be under the same ctx::mutex as perf_install_in_context(),
11192 * because we need to serialize with concurrent event creation.
11194 if (!exclusive_event_installable(event
, ctx
)) {
11199 WARN_ON_ONCE(ctx
->parent_ctx
);
11202 * This is the point on no return; we cannot fail hereafter. This is
11203 * where we start modifying current state.
11208 * See perf_event_ctx_lock() for comments on the details
11209 * of swizzling perf_event::ctx.
11211 perf_remove_from_context(group_leader
, 0);
11214 for_each_sibling_event(sibling
, group_leader
) {
11215 perf_remove_from_context(sibling
, 0);
11220 * Wait for everybody to stop referencing the events through
11221 * the old lists, before installing it on new lists.
11226 * Install the group siblings before the group leader.
11228 * Because a group leader will try and install the entire group
11229 * (through the sibling list, which is still in-tact), we can
11230 * end up with siblings installed in the wrong context.
11232 * By installing siblings first we NO-OP because they're not
11233 * reachable through the group lists.
11235 for_each_sibling_event(sibling
, group_leader
) {
11236 perf_event__state_init(sibling
);
11237 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
11242 * Removing from the context ends up with disabled
11243 * event. What we want here is event in the initial
11244 * startup state, ready to be add into new context.
11246 perf_event__state_init(group_leader
);
11247 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
11252 * Precalculate sample_data sizes; do while holding ctx::mutex such
11253 * that we're serialized against further additions and before
11254 * perf_install_in_context() which is the point the event is active and
11255 * can use these values.
11257 perf_event__header_size(event
);
11258 perf_event__id_header_size(event
);
11260 event
->owner
= current
;
11262 perf_install_in_context(ctx
, event
, event
->cpu
);
11263 perf_unpin_context(ctx
);
11266 perf_event_ctx_unlock(group_leader
, gctx
);
11267 mutex_unlock(&ctx
->mutex
);
11270 mutex_unlock(&task
->signal
->cred_guard_mutex
);
11271 put_task_struct(task
);
11274 mutex_lock(¤t
->perf_event_mutex
);
11275 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
11276 mutex_unlock(¤t
->perf_event_mutex
);
11279 * Drop the reference on the group_event after placing the
11280 * new event on the sibling_list. This ensures destruction
11281 * of the group leader will find the pointer to itself in
11282 * perf_group_detach().
11285 fd_install(event_fd
, event_file
);
11290 perf_event_ctx_unlock(group_leader
, gctx
);
11291 mutex_unlock(&ctx
->mutex
);
11295 perf_unpin_context(ctx
);
11299 * If event_file is set, the fput() above will have called ->release()
11300 * and that will take care of freeing the event.
11306 mutex_unlock(&task
->signal
->cred_guard_mutex
);
11309 put_task_struct(task
);
11313 put_unused_fd(event_fd
);
11318 * perf_event_create_kernel_counter
11320 * @attr: attributes of the counter to create
11321 * @cpu: cpu in which the counter is bound
11322 * @task: task to profile (NULL for percpu)
11324 struct perf_event
*
11325 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
11326 struct task_struct
*task
,
11327 perf_overflow_handler_t overflow_handler
,
11330 struct perf_event_context
*ctx
;
11331 struct perf_event
*event
;
11335 * Get the target context (task or percpu):
11338 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
11339 overflow_handler
, context
, -1);
11340 if (IS_ERR(event
)) {
11341 err
= PTR_ERR(event
);
11345 /* Mark owner so we could distinguish it from user events. */
11346 event
->owner
= TASK_TOMBSTONE
;
11348 ctx
= find_get_context(event
->pmu
, task
, event
);
11350 err
= PTR_ERR(ctx
);
11354 WARN_ON_ONCE(ctx
->parent_ctx
);
11355 mutex_lock(&ctx
->mutex
);
11356 if (ctx
->task
== TASK_TOMBSTONE
) {
11363 * Check if the @cpu we're creating an event for is online.
11365 * We use the perf_cpu_context::ctx::mutex to serialize against
11366 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
11368 struct perf_cpu_context
*cpuctx
=
11369 container_of(ctx
, struct perf_cpu_context
, ctx
);
11370 if (!cpuctx
->online
) {
11376 if (!exclusive_event_installable(event
, ctx
)) {
11381 perf_install_in_context(ctx
, event
, event
->cpu
);
11382 perf_unpin_context(ctx
);
11383 mutex_unlock(&ctx
->mutex
);
11388 mutex_unlock(&ctx
->mutex
);
11389 perf_unpin_context(ctx
);
11394 return ERR_PTR(err
);
11396 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
11398 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
11400 struct perf_event_context
*src_ctx
;
11401 struct perf_event_context
*dst_ctx
;
11402 struct perf_event
*event
, *tmp
;
11405 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
11406 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
11409 * See perf_event_ctx_lock() for comments on the details
11410 * of swizzling perf_event::ctx.
11412 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
11413 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
11415 perf_remove_from_context(event
, 0);
11416 unaccount_event_cpu(event
, src_cpu
);
11418 list_add(&event
->migrate_entry
, &events
);
11422 * Wait for the events to quiesce before re-instating them.
11427 * Re-instate events in 2 passes.
11429 * Skip over group leaders and only install siblings on this first
11430 * pass, siblings will not get enabled without a leader, however a
11431 * leader will enable its siblings, even if those are still on the old
11434 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
11435 if (event
->group_leader
== event
)
11438 list_del(&event
->migrate_entry
);
11439 if (event
->state
>= PERF_EVENT_STATE_OFF
)
11440 event
->state
= PERF_EVENT_STATE_INACTIVE
;
11441 account_event_cpu(event
, dst_cpu
);
11442 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
11447 * Once all the siblings are setup properly, install the group leaders
11450 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
11451 list_del(&event
->migrate_entry
);
11452 if (event
->state
>= PERF_EVENT_STATE_OFF
)
11453 event
->state
= PERF_EVENT_STATE_INACTIVE
;
11454 account_event_cpu(event
, dst_cpu
);
11455 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
11458 mutex_unlock(&dst_ctx
->mutex
);
11459 mutex_unlock(&src_ctx
->mutex
);
11461 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
11463 static void sync_child_event(struct perf_event
*child_event
,
11464 struct task_struct
*child
)
11466 struct perf_event
*parent_event
= child_event
->parent
;
11469 if (child_event
->attr
.inherit_stat
)
11470 perf_event_read_event(child_event
, child
);
11472 child_val
= perf_event_count(child_event
);
11475 * Add back the child's count to the parent's count:
11477 atomic64_add(child_val
, &parent_event
->child_count
);
11478 atomic64_add(child_event
->total_time_enabled
,
11479 &parent_event
->child_total_time_enabled
);
11480 atomic64_add(child_event
->total_time_running
,
11481 &parent_event
->child_total_time_running
);
11485 perf_event_exit_event(struct perf_event
*child_event
,
11486 struct perf_event_context
*child_ctx
,
11487 struct task_struct
*child
)
11489 struct perf_event
*parent_event
= child_event
->parent
;
11492 * Do not destroy the 'original' grouping; because of the context
11493 * switch optimization the original events could've ended up in a
11494 * random child task.
11496 * If we were to destroy the original group, all group related
11497 * operations would cease to function properly after this random
11500 * Do destroy all inherited groups, we don't care about those
11501 * and being thorough is better.
11503 raw_spin_lock_irq(&child_ctx
->lock
);
11504 WARN_ON_ONCE(child_ctx
->is_active
);
11507 perf_group_detach(child_event
);
11508 list_del_event(child_event
, child_ctx
);
11509 perf_event_set_state(child_event
, PERF_EVENT_STATE_EXIT
); /* is_event_hup() */
11510 raw_spin_unlock_irq(&child_ctx
->lock
);
11513 * Parent events are governed by their filedesc, retain them.
11515 if (!parent_event
) {
11516 perf_event_wakeup(child_event
);
11520 * Child events can be cleaned up.
11523 sync_child_event(child_event
, child
);
11526 * Remove this event from the parent's list
11528 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
11529 mutex_lock(&parent_event
->child_mutex
);
11530 list_del_init(&child_event
->child_list
);
11531 mutex_unlock(&parent_event
->child_mutex
);
11534 * Kick perf_poll() for is_event_hup().
11536 perf_event_wakeup(parent_event
);
11537 free_event(child_event
);
11538 put_event(parent_event
);
11541 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
11543 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
11544 struct perf_event
*child_event
, *next
;
11546 WARN_ON_ONCE(child
!= current
);
11548 child_ctx
= perf_pin_task_context(child
, ctxn
);
11553 * In order to reduce the amount of tricky in ctx tear-down, we hold
11554 * ctx::mutex over the entire thing. This serializes against almost
11555 * everything that wants to access the ctx.
11557 * The exception is sys_perf_event_open() /
11558 * perf_event_create_kernel_count() which does find_get_context()
11559 * without ctx::mutex (it cannot because of the move_group double mutex
11560 * lock thing). See the comments in perf_install_in_context().
11562 mutex_lock(&child_ctx
->mutex
);
11565 * In a single ctx::lock section, de-schedule the events and detach the
11566 * context from the task such that we cannot ever get it scheduled back
11569 raw_spin_lock_irq(&child_ctx
->lock
);
11570 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
11573 * Now that the context is inactive, destroy the task <-> ctx relation
11574 * and mark the context dead.
11576 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
11577 put_ctx(child_ctx
); /* cannot be last */
11578 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
11579 put_task_struct(current
); /* cannot be last */
11581 clone_ctx
= unclone_ctx(child_ctx
);
11582 raw_spin_unlock_irq(&child_ctx
->lock
);
11585 put_ctx(clone_ctx
);
11588 * Report the task dead after unscheduling the events so that we
11589 * won't get any samples after PERF_RECORD_EXIT. We can however still
11590 * get a few PERF_RECORD_READ events.
11592 perf_event_task(child
, child_ctx
, 0);
11594 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
11595 perf_event_exit_event(child_event
, child_ctx
, child
);
11597 mutex_unlock(&child_ctx
->mutex
);
11599 put_ctx(child_ctx
);
11603 * When a child task exits, feed back event values to parent events.
11605 * Can be called with cred_guard_mutex held when called from
11606 * install_exec_creds().
11608 void perf_event_exit_task(struct task_struct
*child
)
11610 struct perf_event
*event
, *tmp
;
11613 mutex_lock(&child
->perf_event_mutex
);
11614 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
11616 list_del_init(&event
->owner_entry
);
11619 * Ensure the list deletion is visible before we clear
11620 * the owner, closes a race against perf_release() where
11621 * we need to serialize on the owner->perf_event_mutex.
11623 smp_store_release(&event
->owner
, NULL
);
11625 mutex_unlock(&child
->perf_event_mutex
);
11627 for_each_task_context_nr(ctxn
)
11628 perf_event_exit_task_context(child
, ctxn
);
11631 * The perf_event_exit_task_context calls perf_event_task
11632 * with child's task_ctx, which generates EXIT events for
11633 * child contexts and sets child->perf_event_ctxp[] to NULL.
11634 * At this point we need to send EXIT events to cpu contexts.
11636 perf_event_task(child
, NULL
, 0);
11639 static void perf_free_event(struct perf_event
*event
,
11640 struct perf_event_context
*ctx
)
11642 struct perf_event
*parent
= event
->parent
;
11644 if (WARN_ON_ONCE(!parent
))
11647 mutex_lock(&parent
->child_mutex
);
11648 list_del_init(&event
->child_list
);
11649 mutex_unlock(&parent
->child_mutex
);
11653 raw_spin_lock_irq(&ctx
->lock
);
11654 perf_group_detach(event
);
11655 list_del_event(event
, ctx
);
11656 raw_spin_unlock_irq(&ctx
->lock
);
11661 * Free a context as created by inheritance by perf_event_init_task() below,
11662 * used by fork() in case of fail.
11664 * Even though the task has never lived, the context and events have been
11665 * exposed through the child_list, so we must take care tearing it all down.
11667 void perf_event_free_task(struct task_struct
*task
)
11669 struct perf_event_context
*ctx
;
11670 struct perf_event
*event
, *tmp
;
11673 for_each_task_context_nr(ctxn
) {
11674 ctx
= task
->perf_event_ctxp
[ctxn
];
11678 mutex_lock(&ctx
->mutex
);
11679 raw_spin_lock_irq(&ctx
->lock
);
11681 * Destroy the task <-> ctx relation and mark the context dead.
11683 * This is important because even though the task hasn't been
11684 * exposed yet the context has been (through child_list).
11686 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
11687 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
11688 put_task_struct(task
); /* cannot be last */
11689 raw_spin_unlock_irq(&ctx
->lock
);
11691 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
11692 perf_free_event(event
, ctx
);
11694 mutex_unlock(&ctx
->mutex
);
11697 * perf_event_release_kernel() could've stolen some of our
11698 * child events and still have them on its free_list. In that
11699 * case we must wait for these events to have been freed (in
11700 * particular all their references to this task must've been
11703 * Without this copy_process() will unconditionally free this
11704 * task (irrespective of its reference count) and
11705 * _free_event()'s put_task_struct(event->hw.target) will be a
11708 * Wait for all events to drop their context reference.
11710 wait_var_event(&ctx
->refcount
, refcount_read(&ctx
->refcount
) == 1);
11711 put_ctx(ctx
); /* must be last */
11715 void perf_event_delayed_put(struct task_struct
*task
)
11719 for_each_task_context_nr(ctxn
)
11720 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
11723 struct file
*perf_event_get(unsigned int fd
)
11725 struct file
*file
= fget(fd
);
11727 return ERR_PTR(-EBADF
);
11729 if (file
->f_op
!= &perf_fops
) {
11731 return ERR_PTR(-EBADF
);
11737 const struct perf_event
*perf_get_event(struct file
*file
)
11739 if (file
->f_op
!= &perf_fops
)
11740 return ERR_PTR(-EINVAL
);
11742 return file
->private_data
;
11745 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
11748 return ERR_PTR(-EINVAL
);
11750 return &event
->attr
;
11754 * Inherit an event from parent task to child task.
11757 * - valid pointer on success
11758 * - NULL for orphaned events
11759 * - IS_ERR() on error
11761 static struct perf_event
*
11762 inherit_event(struct perf_event
*parent_event
,
11763 struct task_struct
*parent
,
11764 struct perf_event_context
*parent_ctx
,
11765 struct task_struct
*child
,
11766 struct perf_event
*group_leader
,
11767 struct perf_event_context
*child_ctx
)
11769 enum perf_event_state parent_state
= parent_event
->state
;
11770 struct perf_event
*child_event
;
11771 unsigned long flags
;
11774 * Instead of creating recursive hierarchies of events,
11775 * we link inherited events back to the original parent,
11776 * which has a filp for sure, which we use as the reference
11779 if (parent_event
->parent
)
11780 parent_event
= parent_event
->parent
;
11782 child_event
= perf_event_alloc(&parent_event
->attr
,
11785 group_leader
, parent_event
,
11787 if (IS_ERR(child_event
))
11788 return child_event
;
11791 if ((child_event
->attach_state
& PERF_ATTACH_TASK_DATA
) &&
11792 !child_ctx
->task_ctx_data
) {
11793 struct pmu
*pmu
= child_event
->pmu
;
11795 child_ctx
->task_ctx_data
= kzalloc(pmu
->task_ctx_size
,
11797 if (!child_ctx
->task_ctx_data
) {
11798 free_event(child_event
);
11804 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
11805 * must be under the same lock in order to serialize against
11806 * perf_event_release_kernel(), such that either we must observe
11807 * is_orphaned_event() or they will observe us on the child_list.
11809 mutex_lock(&parent_event
->child_mutex
);
11810 if (is_orphaned_event(parent_event
) ||
11811 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
11812 mutex_unlock(&parent_event
->child_mutex
);
11813 /* task_ctx_data is freed with child_ctx */
11814 free_event(child_event
);
11818 get_ctx(child_ctx
);
11821 * Make the child state follow the state of the parent event,
11822 * not its attr.disabled bit. We hold the parent's mutex,
11823 * so we won't race with perf_event_{en, dis}able_family.
11825 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
11826 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
11828 child_event
->state
= PERF_EVENT_STATE_OFF
;
11830 if (parent_event
->attr
.freq
) {
11831 u64 sample_period
= parent_event
->hw
.sample_period
;
11832 struct hw_perf_event
*hwc
= &child_event
->hw
;
11834 hwc
->sample_period
= sample_period
;
11835 hwc
->last_period
= sample_period
;
11837 local64_set(&hwc
->period_left
, sample_period
);
11840 child_event
->ctx
= child_ctx
;
11841 child_event
->overflow_handler
= parent_event
->overflow_handler
;
11842 child_event
->overflow_handler_context
11843 = parent_event
->overflow_handler_context
;
11846 * Precalculate sample_data sizes
11848 perf_event__header_size(child_event
);
11849 perf_event__id_header_size(child_event
);
11852 * Link it up in the child's context:
11854 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
11855 add_event_to_ctx(child_event
, child_ctx
);
11856 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
11859 * Link this into the parent event's child list
11861 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
11862 mutex_unlock(&parent_event
->child_mutex
);
11864 return child_event
;
11868 * Inherits an event group.
11870 * This will quietly suppress orphaned events; !inherit_event() is not an error.
11871 * This matches with perf_event_release_kernel() removing all child events.
11877 static int inherit_group(struct perf_event
*parent_event
,
11878 struct task_struct
*parent
,
11879 struct perf_event_context
*parent_ctx
,
11880 struct task_struct
*child
,
11881 struct perf_event_context
*child_ctx
)
11883 struct perf_event
*leader
;
11884 struct perf_event
*sub
;
11885 struct perf_event
*child_ctr
;
11887 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
11888 child
, NULL
, child_ctx
);
11889 if (IS_ERR(leader
))
11890 return PTR_ERR(leader
);
11892 * @leader can be NULL here because of is_orphaned_event(). In this
11893 * case inherit_event() will create individual events, similar to what
11894 * perf_group_detach() would do anyway.
11896 for_each_sibling_event(sub
, parent_event
) {
11897 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
11898 child
, leader
, child_ctx
);
11899 if (IS_ERR(child_ctr
))
11900 return PTR_ERR(child_ctr
);
11902 if (sub
->aux_event
== parent_event
&&
11903 !perf_get_aux_event(child_ctr
, leader
))
11910 * Creates the child task context and tries to inherit the event-group.
11912 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
11913 * inherited_all set when we 'fail' to inherit an orphaned event; this is
11914 * consistent with perf_event_release_kernel() removing all child events.
11921 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
11922 struct perf_event_context
*parent_ctx
,
11923 struct task_struct
*child
, int ctxn
,
11924 int *inherited_all
)
11927 struct perf_event_context
*child_ctx
;
11929 if (!event
->attr
.inherit
) {
11930 *inherited_all
= 0;
11934 child_ctx
= child
->perf_event_ctxp
[ctxn
];
11937 * This is executed from the parent task context, so
11938 * inherit events that have been marked for cloning.
11939 * First allocate and initialize a context for the
11942 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
11946 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
11949 ret
= inherit_group(event
, parent
, parent_ctx
,
11953 *inherited_all
= 0;
11959 * Initialize the perf_event context in task_struct
11961 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
11963 struct perf_event_context
*child_ctx
, *parent_ctx
;
11964 struct perf_event_context
*cloned_ctx
;
11965 struct perf_event
*event
;
11966 struct task_struct
*parent
= current
;
11967 int inherited_all
= 1;
11968 unsigned long flags
;
11971 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
11975 * If the parent's context is a clone, pin it so it won't get
11976 * swapped under us.
11978 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
11983 * No need to check if parent_ctx != NULL here; since we saw
11984 * it non-NULL earlier, the only reason for it to become NULL
11985 * is if we exit, and since we're currently in the middle of
11986 * a fork we can't be exiting at the same time.
11990 * Lock the parent list. No need to lock the child - not PID
11991 * hashed yet and not running, so nobody can access it.
11993 mutex_lock(&parent_ctx
->mutex
);
11996 * We dont have to disable NMIs - we are only looking at
11997 * the list, not manipulating it:
11999 perf_event_groups_for_each(event
, &parent_ctx
->pinned_groups
) {
12000 ret
= inherit_task_group(event
, parent
, parent_ctx
,
12001 child
, ctxn
, &inherited_all
);
12007 * We can't hold ctx->lock when iterating the ->flexible_group list due
12008 * to allocations, but we need to prevent rotation because
12009 * rotate_ctx() will change the list from interrupt context.
12011 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
12012 parent_ctx
->rotate_disable
= 1;
12013 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
12015 perf_event_groups_for_each(event
, &parent_ctx
->flexible_groups
) {
12016 ret
= inherit_task_group(event
, parent
, parent_ctx
,
12017 child
, ctxn
, &inherited_all
);
12022 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
12023 parent_ctx
->rotate_disable
= 0;
12025 child_ctx
= child
->perf_event_ctxp
[ctxn
];
12027 if (child_ctx
&& inherited_all
) {
12029 * Mark the child context as a clone of the parent
12030 * context, or of whatever the parent is a clone of.
12032 * Note that if the parent is a clone, the holding of
12033 * parent_ctx->lock avoids it from being uncloned.
12035 cloned_ctx
= parent_ctx
->parent_ctx
;
12037 child_ctx
->parent_ctx
= cloned_ctx
;
12038 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
12040 child_ctx
->parent_ctx
= parent_ctx
;
12041 child_ctx
->parent_gen
= parent_ctx
->generation
;
12043 get_ctx(child_ctx
->parent_ctx
);
12046 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
12048 mutex_unlock(&parent_ctx
->mutex
);
12050 perf_unpin_context(parent_ctx
);
12051 put_ctx(parent_ctx
);
12057 * Initialize the perf_event context in task_struct
12059 int perf_event_init_task(struct task_struct
*child
)
12063 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
12064 mutex_init(&child
->perf_event_mutex
);
12065 INIT_LIST_HEAD(&child
->perf_event_list
);
12067 for_each_task_context_nr(ctxn
) {
12068 ret
= perf_event_init_context(child
, ctxn
);
12070 perf_event_free_task(child
);
12078 static void __init
perf_event_init_all_cpus(void)
12080 struct swevent_htable
*swhash
;
12083 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
12085 for_each_possible_cpu(cpu
) {
12086 swhash
= &per_cpu(swevent_htable
, cpu
);
12087 mutex_init(&swhash
->hlist_mutex
);
12088 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
12090 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
12091 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
12093 #ifdef CONFIG_CGROUP_PERF
12094 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
12096 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
12100 static void perf_swevent_init_cpu(unsigned int cpu
)
12102 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
12104 mutex_lock(&swhash
->hlist_mutex
);
12105 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
12106 struct swevent_hlist
*hlist
;
12108 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
12110 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
12112 mutex_unlock(&swhash
->hlist_mutex
);
12115 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
12116 static void __perf_event_exit_context(void *__info
)
12118 struct perf_event_context
*ctx
= __info
;
12119 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
12120 struct perf_event
*event
;
12122 raw_spin_lock(&ctx
->lock
);
12123 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
12124 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
12125 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
12126 raw_spin_unlock(&ctx
->lock
);
12129 static void perf_event_exit_cpu_context(int cpu
)
12131 struct perf_cpu_context
*cpuctx
;
12132 struct perf_event_context
*ctx
;
12135 mutex_lock(&pmus_lock
);
12136 list_for_each_entry(pmu
, &pmus
, entry
) {
12137 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
12138 ctx
= &cpuctx
->ctx
;
12140 mutex_lock(&ctx
->mutex
);
12141 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
12142 cpuctx
->online
= 0;
12143 mutex_unlock(&ctx
->mutex
);
12145 cpumask_clear_cpu(cpu
, perf_online_mask
);
12146 mutex_unlock(&pmus_lock
);
12150 static void perf_event_exit_cpu_context(int cpu
) { }
12154 int perf_event_init_cpu(unsigned int cpu
)
12156 struct perf_cpu_context
*cpuctx
;
12157 struct perf_event_context
*ctx
;
12160 perf_swevent_init_cpu(cpu
);
12162 mutex_lock(&pmus_lock
);
12163 cpumask_set_cpu(cpu
, perf_online_mask
);
12164 list_for_each_entry(pmu
, &pmus
, entry
) {
12165 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
12166 ctx
= &cpuctx
->ctx
;
12168 mutex_lock(&ctx
->mutex
);
12169 cpuctx
->online
= 1;
12170 mutex_unlock(&ctx
->mutex
);
12172 mutex_unlock(&pmus_lock
);
12177 int perf_event_exit_cpu(unsigned int cpu
)
12179 perf_event_exit_cpu_context(cpu
);
12184 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
12188 for_each_online_cpu(cpu
)
12189 perf_event_exit_cpu(cpu
);
12195 * Run the perf reboot notifier at the very last possible moment so that
12196 * the generic watchdog code runs as long as possible.
12198 static struct notifier_block perf_reboot_notifier
= {
12199 .notifier_call
= perf_reboot
,
12200 .priority
= INT_MIN
,
12203 void __init
perf_event_init(void)
12207 idr_init(&pmu_idr
);
12209 perf_event_init_all_cpus();
12210 init_srcu_struct(&pmus_srcu
);
12211 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
12212 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
12213 perf_pmu_register(&perf_task_clock
, NULL
, -1);
12214 perf_tp_register();
12215 perf_event_init_cpu(smp_processor_id());
12216 register_reboot_notifier(&perf_reboot_notifier
);
12218 ret
= init_hw_breakpoint();
12219 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
12222 * Build time assertion that we keep the data_head at the intended
12223 * location. IOW, validation we got the __reserved[] size right.
12225 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
12229 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
12232 struct perf_pmu_events_attr
*pmu_attr
=
12233 container_of(attr
, struct perf_pmu_events_attr
, attr
);
12235 if (pmu_attr
->event_str
)
12236 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
12240 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
12242 static int __init
perf_event_sysfs_init(void)
12247 mutex_lock(&pmus_lock
);
12249 ret
= bus_register(&pmu_bus
);
12253 list_for_each_entry(pmu
, &pmus
, entry
) {
12254 if (!pmu
->name
|| pmu
->type
< 0)
12257 ret
= pmu_dev_alloc(pmu
);
12258 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
12260 pmu_bus_running
= 1;
12264 mutex_unlock(&pmus_lock
);
12268 device_initcall(perf_event_sysfs_init
);
12270 #ifdef CONFIG_CGROUP_PERF
12271 static struct cgroup_subsys_state
*
12272 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
12274 struct perf_cgroup
*jc
;
12276 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
12278 return ERR_PTR(-ENOMEM
);
12280 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
12283 return ERR_PTR(-ENOMEM
);
12289 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
12291 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
12293 free_percpu(jc
->info
);
12297 static int __perf_cgroup_move(void *info
)
12299 struct task_struct
*task
= info
;
12301 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
12306 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
12308 struct task_struct
*task
;
12309 struct cgroup_subsys_state
*css
;
12311 cgroup_taskset_for_each(task
, css
, tset
)
12312 task_function_call(task
, __perf_cgroup_move
, task
);
12315 struct cgroup_subsys perf_event_cgrp_subsys
= {
12316 .css_alloc
= perf_cgroup_css_alloc
,
12317 .css_free
= perf_cgroup_css_free
,
12318 .attach
= perf_cgroup_attach
,
12320 * Implicitly enable on dfl hierarchy so that perf events can
12321 * always be filtered by cgroup2 path as long as perf_event
12322 * controller is not mounted on a legacy hierarchy.
12324 .implicit_on_dfl
= true,
12327 #endif /* CONFIG_CGROUP_PERF */