2 * Performance counter core code
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/sysfs.h>
19 #include <linux/ptrace.h>
20 #include <linux/percpu.h>
21 #include <linux/vmstat.h>
22 #include <linux/hardirq.h>
23 #include <linux/rculist.h>
24 #include <linux/uaccess.h>
25 #include <linux/syscalls.h>
26 #include <linux/anon_inodes.h>
27 #include <linux/kernel_stat.h>
28 #include <linux/perf_counter.h>
29 #include <linux/dcache.h>
31 #include <asm/irq_regs.h>
34 * Each CPU has a list of per CPU counters:
36 DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
38 int perf_max_counters __read_mostly
= 1;
39 static int perf_reserved_percpu __read_mostly
;
40 static int perf_overcommit __read_mostly
= 1;
42 static atomic_t nr_counters __read_mostly
;
43 static atomic_t nr_mmap_tracking __read_mostly
;
44 static atomic_t nr_munmap_tracking __read_mostly
;
45 static atomic_t nr_comm_tracking __read_mostly
;
47 int sysctl_perf_counter_priv __read_mostly
; /* do we need to be privileged */
48 int sysctl_perf_counter_mlock __read_mostly
= 128; /* 'free' kb per counter */
51 * Lock for (sysadmin-configurable) counter reservations:
53 static DEFINE_SPINLOCK(perf_resource_lock
);
56 * Architecture provided APIs - weak aliases:
58 extern __weak
const struct pmu
*hw_perf_counter_init(struct perf_counter
*counter
)
63 u64 __weak
hw_perf_save_disable(void) { return 0; }
64 void __weak
hw_perf_restore(u64 ctrl
) { barrier(); }
65 void __weak
hw_perf_counter_setup(int cpu
) { barrier(); }
66 int __weak
hw_perf_group_sched_in(struct perf_counter
*group_leader
,
67 struct perf_cpu_context
*cpuctx
,
68 struct perf_counter_context
*ctx
, int cpu
)
73 void __weak
perf_counter_print_debug(void) { }
76 list_add_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
78 struct perf_counter
*group_leader
= counter
->group_leader
;
81 * Depending on whether it is a standalone or sibling counter,
82 * add it straight to the context's counter list, or to the group
83 * leader's sibling list:
85 if (counter
->group_leader
== counter
)
86 list_add_tail(&counter
->list_entry
, &ctx
->counter_list
);
88 list_add_tail(&counter
->list_entry
, &group_leader
->sibling_list
);
89 group_leader
->nr_siblings
++;
92 list_add_rcu(&counter
->event_entry
, &ctx
->event_list
);
96 list_del_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
98 struct perf_counter
*sibling
, *tmp
;
100 list_del_init(&counter
->list_entry
);
101 list_del_rcu(&counter
->event_entry
);
103 if (counter
->group_leader
!= counter
)
104 counter
->group_leader
->nr_siblings
--;
107 * If this was a group counter with sibling counters then
108 * upgrade the siblings to singleton counters by adding them
109 * to the context list directly:
111 list_for_each_entry_safe(sibling
, tmp
,
112 &counter
->sibling_list
, list_entry
) {
114 list_move_tail(&sibling
->list_entry
, &ctx
->counter_list
);
115 sibling
->group_leader
= sibling
;
120 counter_sched_out(struct perf_counter
*counter
,
121 struct perf_cpu_context
*cpuctx
,
122 struct perf_counter_context
*ctx
)
124 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
127 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
128 counter
->tstamp_stopped
= ctx
->time
;
129 counter
->pmu
->disable(counter
);
132 if (!is_software_counter(counter
))
133 cpuctx
->active_oncpu
--;
135 if (counter
->hw_event
.exclusive
|| !cpuctx
->active_oncpu
)
136 cpuctx
->exclusive
= 0;
140 group_sched_out(struct perf_counter
*group_counter
,
141 struct perf_cpu_context
*cpuctx
,
142 struct perf_counter_context
*ctx
)
144 struct perf_counter
*counter
;
146 if (group_counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
149 counter_sched_out(group_counter
, cpuctx
, ctx
);
152 * Schedule out siblings (if any):
154 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
)
155 counter_sched_out(counter
, cpuctx
, ctx
);
157 if (group_counter
->hw_event
.exclusive
)
158 cpuctx
->exclusive
= 0;
162 * Cross CPU call to remove a performance counter
164 * We disable the counter on the hardware level first. After that we
165 * remove it from the context list.
167 static void __perf_counter_remove_from_context(void *info
)
169 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
170 struct perf_counter
*counter
= info
;
171 struct perf_counter_context
*ctx
= counter
->ctx
;
176 * If this is a task context, we need to check whether it is
177 * the current task context of this cpu. If not it has been
178 * scheduled out before the smp call arrived.
180 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
183 spin_lock_irqsave(&ctx
->lock
, flags
);
185 counter_sched_out(counter
, cpuctx
, ctx
);
187 counter
->task
= NULL
;
191 * Protect the list operation against NMI by disabling the
192 * counters on a global level. NOP for non NMI based counters.
194 perf_flags
= hw_perf_save_disable();
195 list_del_counter(counter
, ctx
);
196 hw_perf_restore(perf_flags
);
200 * Allow more per task counters with respect to the
203 cpuctx
->max_pertask
=
204 min(perf_max_counters
- ctx
->nr_counters
,
205 perf_max_counters
- perf_reserved_percpu
);
208 spin_unlock_irqrestore(&ctx
->lock
, flags
);
213 * Remove the counter from a task's (or a CPU's) list of counters.
215 * Must be called with counter->mutex and ctx->mutex held.
217 * CPU counters are removed with a smp call. For task counters we only
218 * call when the task is on a CPU.
220 static void perf_counter_remove_from_context(struct perf_counter
*counter
)
222 struct perf_counter_context
*ctx
= counter
->ctx
;
223 struct task_struct
*task
= ctx
->task
;
227 * Per cpu counters are removed via an smp call and
228 * the removal is always sucessful.
230 smp_call_function_single(counter
->cpu
,
231 __perf_counter_remove_from_context
,
237 task_oncpu_function_call(task
, __perf_counter_remove_from_context
,
240 spin_lock_irq(&ctx
->lock
);
242 * If the context is active we need to retry the smp call.
244 if (ctx
->nr_active
&& !list_empty(&counter
->list_entry
)) {
245 spin_unlock_irq(&ctx
->lock
);
250 * The lock prevents that this context is scheduled in so we
251 * can remove the counter safely, if the call above did not
254 if (!list_empty(&counter
->list_entry
)) {
256 list_del_counter(counter
, ctx
);
257 counter
->task
= NULL
;
259 spin_unlock_irq(&ctx
->lock
);
262 static inline u64
perf_clock(void)
264 return cpu_clock(smp_processor_id());
268 * Update the record of the current time in a context.
270 static void update_context_time(struct perf_counter_context
*ctx
)
272 u64 now
= perf_clock();
274 ctx
->time
+= now
- ctx
->timestamp
;
275 ctx
->timestamp
= now
;
279 * Update the total_time_enabled and total_time_running fields for a counter.
281 static void update_counter_times(struct perf_counter
*counter
)
283 struct perf_counter_context
*ctx
= counter
->ctx
;
286 if (counter
->state
< PERF_COUNTER_STATE_INACTIVE
)
289 counter
->total_time_enabled
= ctx
->time
- counter
->tstamp_enabled
;
291 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
)
292 run_end
= counter
->tstamp_stopped
;
296 counter
->total_time_running
= run_end
- counter
->tstamp_running
;
300 * Update total_time_enabled and total_time_running for all counters in a group.
302 static void update_group_times(struct perf_counter
*leader
)
304 struct perf_counter
*counter
;
306 update_counter_times(leader
);
307 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
308 update_counter_times(counter
);
312 * Cross CPU call to disable a performance counter
314 static void __perf_counter_disable(void *info
)
316 struct perf_counter
*counter
= info
;
317 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
318 struct perf_counter_context
*ctx
= counter
->ctx
;
322 * If this is a per-task counter, need to check whether this
323 * counter's task is the current task on this cpu.
325 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
328 spin_lock_irqsave(&ctx
->lock
, flags
);
331 * If the counter is on, turn it off.
332 * If it is in error state, leave it in error state.
334 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
) {
335 update_context_time(ctx
);
336 update_counter_times(counter
);
337 if (counter
== counter
->group_leader
)
338 group_sched_out(counter
, cpuctx
, ctx
);
340 counter_sched_out(counter
, cpuctx
, ctx
);
341 counter
->state
= PERF_COUNTER_STATE_OFF
;
344 spin_unlock_irqrestore(&ctx
->lock
, flags
);
350 static void perf_counter_disable(struct perf_counter
*counter
)
352 struct perf_counter_context
*ctx
= counter
->ctx
;
353 struct task_struct
*task
= ctx
->task
;
357 * Disable the counter on the cpu that it's on
359 smp_call_function_single(counter
->cpu
, __perf_counter_disable
,
365 task_oncpu_function_call(task
, __perf_counter_disable
, counter
);
367 spin_lock_irq(&ctx
->lock
);
369 * If the counter is still active, we need to retry the cross-call.
371 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
372 spin_unlock_irq(&ctx
->lock
);
377 * Since we have the lock this context can't be scheduled
378 * in, so we can change the state safely.
380 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
381 update_counter_times(counter
);
382 counter
->state
= PERF_COUNTER_STATE_OFF
;
385 spin_unlock_irq(&ctx
->lock
);
389 * Disable a counter and all its children.
391 static void perf_counter_disable_family(struct perf_counter
*counter
)
393 struct perf_counter
*child
;
395 perf_counter_disable(counter
);
398 * Lock the mutex to protect the list of children
400 mutex_lock(&counter
->mutex
);
401 list_for_each_entry(child
, &counter
->child_list
, child_list
)
402 perf_counter_disable(child
);
403 mutex_unlock(&counter
->mutex
);
407 counter_sched_in(struct perf_counter
*counter
,
408 struct perf_cpu_context
*cpuctx
,
409 struct perf_counter_context
*ctx
,
412 if (counter
->state
<= PERF_COUNTER_STATE_OFF
)
415 counter
->state
= PERF_COUNTER_STATE_ACTIVE
;
416 counter
->oncpu
= cpu
; /* TODO: put 'cpu' into cpuctx->cpu */
418 * The new state must be visible before we turn it on in the hardware:
422 if (counter
->pmu
->enable(counter
)) {
423 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
428 counter
->tstamp_running
+= ctx
->time
- counter
->tstamp_stopped
;
430 if (!is_software_counter(counter
))
431 cpuctx
->active_oncpu
++;
434 if (counter
->hw_event
.exclusive
)
435 cpuctx
->exclusive
= 1;
441 * Return 1 for a group consisting entirely of software counters,
442 * 0 if the group contains any hardware counters.
444 static int is_software_only_group(struct perf_counter
*leader
)
446 struct perf_counter
*counter
;
448 if (!is_software_counter(leader
))
451 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
452 if (!is_software_counter(counter
))
459 * Work out whether we can put this counter group on the CPU now.
461 static int group_can_go_on(struct perf_counter
*counter
,
462 struct perf_cpu_context
*cpuctx
,
466 * Groups consisting entirely of software counters can always go on.
468 if (is_software_only_group(counter
))
471 * If an exclusive group is already on, no other hardware
472 * counters can go on.
474 if (cpuctx
->exclusive
)
477 * If this group is exclusive and there are already
478 * counters on the CPU, it can't go on.
480 if (counter
->hw_event
.exclusive
&& cpuctx
->active_oncpu
)
483 * Otherwise, try to add it if all previous groups were able
489 static void add_counter_to_ctx(struct perf_counter
*counter
,
490 struct perf_counter_context
*ctx
)
492 list_add_counter(counter
, ctx
);
494 counter
->prev_state
= PERF_COUNTER_STATE_OFF
;
495 counter
->tstamp_enabled
= ctx
->time
;
496 counter
->tstamp_running
= ctx
->time
;
497 counter
->tstamp_stopped
= ctx
->time
;
501 * Cross CPU call to install and enable a performance counter
503 static void __perf_install_in_context(void *info
)
505 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
506 struct perf_counter
*counter
= info
;
507 struct perf_counter_context
*ctx
= counter
->ctx
;
508 struct perf_counter
*leader
= counter
->group_leader
;
509 int cpu
= smp_processor_id();
515 * If this is a task context, we need to check whether it is
516 * the current task context of this cpu. If not it has been
517 * scheduled out before the smp call arrived.
519 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
522 spin_lock_irqsave(&ctx
->lock
, flags
);
523 update_context_time(ctx
);
526 * Protect the list operation against NMI by disabling the
527 * counters on a global level. NOP for non NMI based counters.
529 perf_flags
= hw_perf_save_disable();
531 add_counter_to_ctx(counter
, ctx
);
534 * Don't put the counter on if it is disabled or if
535 * it is in a group and the group isn't on.
537 if (counter
->state
!= PERF_COUNTER_STATE_INACTIVE
||
538 (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
))
542 * An exclusive counter can't go on if there are already active
543 * hardware counters, and no hardware counter can go on if there
544 * is already an exclusive counter on.
546 if (!group_can_go_on(counter
, cpuctx
, 1))
549 err
= counter_sched_in(counter
, cpuctx
, ctx
, cpu
);
553 * This counter couldn't go on. If it is in a group
554 * then we have to pull the whole group off.
555 * If the counter group is pinned then put it in error state.
557 if (leader
!= counter
)
558 group_sched_out(leader
, cpuctx
, ctx
);
559 if (leader
->hw_event
.pinned
) {
560 update_group_times(leader
);
561 leader
->state
= PERF_COUNTER_STATE_ERROR
;
565 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
566 cpuctx
->max_pertask
--;
569 hw_perf_restore(perf_flags
);
571 spin_unlock_irqrestore(&ctx
->lock
, flags
);
575 * Attach a performance counter to a context
577 * First we add the counter to the list with the hardware enable bit
578 * in counter->hw_config cleared.
580 * If the counter is attached to a task which is on a CPU we use a smp
581 * call to enable it in the task context. The task might have been
582 * scheduled away, but we check this in the smp call again.
584 * Must be called with ctx->mutex held.
587 perf_install_in_context(struct perf_counter_context
*ctx
,
588 struct perf_counter
*counter
,
591 struct task_struct
*task
= ctx
->task
;
595 * Per cpu counters are installed via an smp call and
596 * the install is always sucessful.
598 smp_call_function_single(cpu
, __perf_install_in_context
,
603 counter
->task
= task
;
605 task_oncpu_function_call(task
, __perf_install_in_context
,
608 spin_lock_irq(&ctx
->lock
);
610 * we need to retry the smp call.
612 if (ctx
->is_active
&& list_empty(&counter
->list_entry
)) {
613 spin_unlock_irq(&ctx
->lock
);
618 * The lock prevents that this context is scheduled in so we
619 * can add the counter safely, if it the call above did not
622 if (list_empty(&counter
->list_entry
))
623 add_counter_to_ctx(counter
, ctx
);
624 spin_unlock_irq(&ctx
->lock
);
628 * Cross CPU call to enable a performance counter
630 static void __perf_counter_enable(void *info
)
632 struct perf_counter
*counter
= info
;
633 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
634 struct perf_counter_context
*ctx
= counter
->ctx
;
635 struct perf_counter
*leader
= counter
->group_leader
;
640 * If this is a per-task counter, need to check whether this
641 * counter's task is the current task on this cpu.
643 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
646 spin_lock_irqsave(&ctx
->lock
, flags
);
647 update_context_time(ctx
);
649 counter
->prev_state
= counter
->state
;
650 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
652 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
653 counter
->tstamp_enabled
= ctx
->time
- counter
->total_time_enabled
;
656 * If the counter is in a group and isn't the group leader,
657 * then don't put it on unless the group is on.
659 if (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
)
662 if (!group_can_go_on(counter
, cpuctx
, 1))
665 err
= counter_sched_in(counter
, cpuctx
, ctx
,
670 * If this counter can't go on and it's part of a
671 * group, then the whole group has to come off.
673 if (leader
!= counter
)
674 group_sched_out(leader
, cpuctx
, ctx
);
675 if (leader
->hw_event
.pinned
) {
676 update_group_times(leader
);
677 leader
->state
= PERF_COUNTER_STATE_ERROR
;
682 spin_unlock_irqrestore(&ctx
->lock
, flags
);
688 static void perf_counter_enable(struct perf_counter
*counter
)
690 struct perf_counter_context
*ctx
= counter
->ctx
;
691 struct task_struct
*task
= ctx
->task
;
695 * Enable the counter on the cpu that it's on
697 smp_call_function_single(counter
->cpu
, __perf_counter_enable
,
702 spin_lock_irq(&ctx
->lock
);
703 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
707 * If the counter is in error state, clear that first.
708 * That way, if we see the counter in error state below, we
709 * know that it has gone back into error state, as distinct
710 * from the task having been scheduled away before the
711 * cross-call arrived.
713 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
714 counter
->state
= PERF_COUNTER_STATE_OFF
;
717 spin_unlock_irq(&ctx
->lock
);
718 task_oncpu_function_call(task
, __perf_counter_enable
, counter
);
720 spin_lock_irq(&ctx
->lock
);
723 * If the context is active and the counter is still off,
724 * we need to retry the cross-call.
726 if (ctx
->is_active
&& counter
->state
== PERF_COUNTER_STATE_OFF
)
730 * Since we have the lock this context can't be scheduled
731 * in, so we can change the state safely.
733 if (counter
->state
== PERF_COUNTER_STATE_OFF
) {
734 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
735 counter
->tstamp_enabled
=
736 ctx
->time
- counter
->total_time_enabled
;
739 spin_unlock_irq(&ctx
->lock
);
742 static int perf_counter_refresh(struct perf_counter
*counter
, int refresh
)
745 * not supported on inherited counters
747 if (counter
->hw_event
.inherit
)
750 atomic_add(refresh
, &counter
->event_limit
);
751 perf_counter_enable(counter
);
757 * Enable a counter and all its children.
759 static void perf_counter_enable_family(struct perf_counter
*counter
)
761 struct perf_counter
*child
;
763 perf_counter_enable(counter
);
766 * Lock the mutex to protect the list of children
768 mutex_lock(&counter
->mutex
);
769 list_for_each_entry(child
, &counter
->child_list
, child_list
)
770 perf_counter_enable(child
);
771 mutex_unlock(&counter
->mutex
);
774 void __perf_counter_sched_out(struct perf_counter_context
*ctx
,
775 struct perf_cpu_context
*cpuctx
)
777 struct perf_counter
*counter
;
780 spin_lock(&ctx
->lock
);
782 if (likely(!ctx
->nr_counters
))
784 update_context_time(ctx
);
786 flags
= hw_perf_save_disable();
787 if (ctx
->nr_active
) {
788 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
)
789 group_sched_out(counter
, cpuctx
, ctx
);
791 hw_perf_restore(flags
);
793 spin_unlock(&ctx
->lock
);
797 * Called from scheduler to remove the counters of the current task,
798 * with interrupts disabled.
800 * We stop each counter and update the counter value in counter->count.
802 * This does not protect us against NMI, but disable()
803 * sets the disabled bit in the control field of counter _before_
804 * accessing the counter control register. If a NMI hits, then it will
805 * not restart the counter.
807 void perf_counter_task_sched_out(struct task_struct
*task
, int cpu
)
809 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
810 struct perf_counter_context
*ctx
= &task
->perf_counter_ctx
;
811 struct pt_regs
*regs
;
813 if (likely(!cpuctx
->task_ctx
))
816 update_context_time(ctx
);
818 regs
= task_pt_regs(task
);
819 perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES
, 1, 1, regs
, 0);
820 __perf_counter_sched_out(ctx
, cpuctx
);
822 cpuctx
->task_ctx
= NULL
;
825 static void perf_counter_cpu_sched_out(struct perf_cpu_context
*cpuctx
)
827 __perf_counter_sched_out(&cpuctx
->ctx
, cpuctx
);
831 group_sched_in(struct perf_counter
*group_counter
,
832 struct perf_cpu_context
*cpuctx
,
833 struct perf_counter_context
*ctx
,
836 struct perf_counter
*counter
, *partial_group
;
839 if (group_counter
->state
== PERF_COUNTER_STATE_OFF
)
842 ret
= hw_perf_group_sched_in(group_counter
, cpuctx
, ctx
, cpu
);
844 return ret
< 0 ? ret
: 0;
846 group_counter
->prev_state
= group_counter
->state
;
847 if (counter_sched_in(group_counter
, cpuctx
, ctx
, cpu
))
851 * Schedule in siblings as one group (if any):
853 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
854 counter
->prev_state
= counter
->state
;
855 if (counter_sched_in(counter
, cpuctx
, ctx
, cpu
)) {
856 partial_group
= counter
;
865 * Groups can be scheduled in as one unit only, so undo any
866 * partial group before returning:
868 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
869 if (counter
== partial_group
)
871 counter_sched_out(counter
, cpuctx
, ctx
);
873 counter_sched_out(group_counter
, cpuctx
, ctx
);
879 __perf_counter_sched_in(struct perf_counter_context
*ctx
,
880 struct perf_cpu_context
*cpuctx
, int cpu
)
882 struct perf_counter
*counter
;
886 spin_lock(&ctx
->lock
);
888 if (likely(!ctx
->nr_counters
))
891 ctx
->timestamp
= perf_clock();
893 flags
= hw_perf_save_disable();
896 * First go through the list and put on any pinned groups
897 * in order to give them the best chance of going on.
899 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
900 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
901 !counter
->hw_event
.pinned
)
903 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
906 if (group_can_go_on(counter
, cpuctx
, 1))
907 group_sched_in(counter
, cpuctx
, ctx
, cpu
);
910 * If this pinned group hasn't been scheduled,
911 * put it in error state.
913 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
914 update_group_times(counter
);
915 counter
->state
= PERF_COUNTER_STATE_ERROR
;
919 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
921 * Ignore counters in OFF or ERROR state, and
922 * ignore pinned counters since we did them already.
924 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
925 counter
->hw_event
.pinned
)
929 * Listen to the 'cpu' scheduling filter constraint
932 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
935 if (group_can_go_on(counter
, cpuctx
, can_add_hw
)) {
936 if (group_sched_in(counter
, cpuctx
, ctx
, cpu
))
940 hw_perf_restore(flags
);
942 spin_unlock(&ctx
->lock
);
946 * Called from scheduler to add the counters of the current task
947 * with interrupts disabled.
949 * We restore the counter value and then enable it.
951 * This does not protect us against NMI, but enable()
952 * sets the enabled bit in the control field of counter _before_
953 * accessing the counter control register. If a NMI hits, then it will
954 * keep the counter running.
956 void perf_counter_task_sched_in(struct task_struct
*task
, int cpu
)
958 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
959 struct perf_counter_context
*ctx
= &task
->perf_counter_ctx
;
961 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
962 cpuctx
->task_ctx
= ctx
;
965 static void perf_counter_cpu_sched_in(struct perf_cpu_context
*cpuctx
, int cpu
)
967 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
969 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
972 int perf_counter_task_disable(void)
974 struct task_struct
*curr
= current
;
975 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
976 struct perf_counter
*counter
;
981 if (likely(!ctx
->nr_counters
))
984 local_irq_save(flags
);
985 cpu
= smp_processor_id();
987 perf_counter_task_sched_out(curr
, cpu
);
989 spin_lock(&ctx
->lock
);
992 * Disable all the counters:
994 perf_flags
= hw_perf_save_disable();
996 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
997 if (counter
->state
!= PERF_COUNTER_STATE_ERROR
) {
998 update_group_times(counter
);
999 counter
->state
= PERF_COUNTER_STATE_OFF
;
1003 hw_perf_restore(perf_flags
);
1005 spin_unlock_irqrestore(&ctx
->lock
, flags
);
1010 int perf_counter_task_enable(void)
1012 struct task_struct
*curr
= current
;
1013 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
1014 struct perf_counter
*counter
;
1015 unsigned long flags
;
1019 if (likely(!ctx
->nr_counters
))
1022 local_irq_save(flags
);
1023 cpu
= smp_processor_id();
1025 perf_counter_task_sched_out(curr
, cpu
);
1027 spin_lock(&ctx
->lock
);
1030 * Disable all the counters:
1032 perf_flags
= hw_perf_save_disable();
1034 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1035 if (counter
->state
> PERF_COUNTER_STATE_OFF
)
1037 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
1038 counter
->tstamp_enabled
=
1039 ctx
->time
- counter
->total_time_enabled
;
1040 counter
->hw_event
.disabled
= 0;
1042 hw_perf_restore(perf_flags
);
1044 spin_unlock(&ctx
->lock
);
1046 perf_counter_task_sched_in(curr
, cpu
);
1048 local_irq_restore(flags
);
1054 * Round-robin a context's counters:
1056 static void rotate_ctx(struct perf_counter_context
*ctx
)
1058 struct perf_counter
*counter
;
1061 if (!ctx
->nr_counters
)
1064 spin_lock(&ctx
->lock
);
1066 * Rotate the first entry last (works just fine for group counters too):
1068 perf_flags
= hw_perf_save_disable();
1069 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1070 list_move_tail(&counter
->list_entry
, &ctx
->counter_list
);
1073 hw_perf_restore(perf_flags
);
1075 spin_unlock(&ctx
->lock
);
1078 void perf_counter_task_tick(struct task_struct
*curr
, int cpu
)
1080 struct perf_cpu_context
*cpuctx
;
1081 struct perf_counter_context
*ctx
;
1083 if (!atomic_read(&nr_counters
))
1086 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1087 ctx
= &curr
->perf_counter_ctx
;
1089 perf_counter_cpu_sched_out(cpuctx
);
1090 perf_counter_task_sched_out(curr
, cpu
);
1092 rotate_ctx(&cpuctx
->ctx
);
1095 perf_counter_cpu_sched_in(cpuctx
, cpu
);
1096 perf_counter_task_sched_in(curr
, cpu
);
1100 * Cross CPU call to read the hardware counter
1102 static void __read(void *info
)
1104 struct perf_counter
*counter
= info
;
1105 struct perf_counter_context
*ctx
= counter
->ctx
;
1106 unsigned long flags
;
1108 local_irq_save(flags
);
1110 update_context_time(ctx
);
1111 counter
->pmu
->read(counter
);
1112 update_counter_times(counter
);
1113 local_irq_restore(flags
);
1116 static u64
perf_counter_read(struct perf_counter
*counter
)
1119 * If counter is enabled and currently active on a CPU, update the
1120 * value in the counter structure:
1122 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
1123 smp_call_function_single(counter
->oncpu
,
1124 __read
, counter
, 1);
1125 } else if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
1126 update_counter_times(counter
);
1129 return atomic64_read(&counter
->count
);
1132 static void put_context(struct perf_counter_context
*ctx
)
1135 put_task_struct(ctx
->task
);
1138 static struct perf_counter_context
*find_get_context(pid_t pid
, int cpu
)
1140 struct perf_cpu_context
*cpuctx
;
1141 struct perf_counter_context
*ctx
;
1142 struct task_struct
*task
;
1145 * If cpu is not a wildcard then this is a percpu counter:
1148 /* Must be root to operate on a CPU counter: */
1149 if (sysctl_perf_counter_priv
&& !capable(CAP_SYS_ADMIN
))
1150 return ERR_PTR(-EACCES
);
1152 if (cpu
< 0 || cpu
> num_possible_cpus())
1153 return ERR_PTR(-EINVAL
);
1156 * We could be clever and allow to attach a counter to an
1157 * offline CPU and activate it when the CPU comes up, but
1160 if (!cpu_isset(cpu
, cpu_online_map
))
1161 return ERR_PTR(-ENODEV
);
1163 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1173 task
= find_task_by_vpid(pid
);
1175 get_task_struct(task
);
1179 return ERR_PTR(-ESRCH
);
1181 ctx
= &task
->perf_counter_ctx
;
1184 /* Reuse ptrace permission checks for now. */
1185 if (!ptrace_may_access(task
, PTRACE_MODE_READ
)) {
1187 return ERR_PTR(-EACCES
);
1193 static void free_counter_rcu(struct rcu_head
*head
)
1195 struct perf_counter
*counter
;
1197 counter
= container_of(head
, struct perf_counter
, rcu_head
);
1201 static void perf_pending_sync(struct perf_counter
*counter
);
1203 static void free_counter(struct perf_counter
*counter
)
1205 perf_pending_sync(counter
);
1207 atomic_dec(&nr_counters
);
1208 if (counter
->hw_event
.mmap
)
1209 atomic_dec(&nr_mmap_tracking
);
1210 if (counter
->hw_event
.munmap
)
1211 atomic_dec(&nr_munmap_tracking
);
1212 if (counter
->hw_event
.comm
)
1213 atomic_dec(&nr_comm_tracking
);
1215 if (counter
->destroy
)
1216 counter
->destroy(counter
);
1218 call_rcu(&counter
->rcu_head
, free_counter_rcu
);
1222 * Called when the last reference to the file is gone.
1224 static int perf_release(struct inode
*inode
, struct file
*file
)
1226 struct perf_counter
*counter
= file
->private_data
;
1227 struct perf_counter_context
*ctx
= counter
->ctx
;
1229 file
->private_data
= NULL
;
1231 mutex_lock(&ctx
->mutex
);
1232 mutex_lock(&counter
->mutex
);
1234 perf_counter_remove_from_context(counter
);
1236 mutex_unlock(&counter
->mutex
);
1237 mutex_unlock(&ctx
->mutex
);
1239 free_counter(counter
);
1246 * Read the performance counter - simple non blocking version for now
1249 perf_read_hw(struct perf_counter
*counter
, char __user
*buf
, size_t count
)
1255 * Return end-of-file for a read on a counter that is in
1256 * error state (i.e. because it was pinned but it couldn't be
1257 * scheduled on to the CPU at some point).
1259 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
1262 mutex_lock(&counter
->mutex
);
1263 values
[0] = perf_counter_read(counter
);
1265 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1266 values
[n
++] = counter
->total_time_enabled
+
1267 atomic64_read(&counter
->child_total_time_enabled
);
1268 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1269 values
[n
++] = counter
->total_time_running
+
1270 atomic64_read(&counter
->child_total_time_running
);
1271 mutex_unlock(&counter
->mutex
);
1273 if (count
< n
* sizeof(u64
))
1275 count
= n
* sizeof(u64
);
1277 if (copy_to_user(buf
, values
, count
))
1284 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
1286 struct perf_counter
*counter
= file
->private_data
;
1288 return perf_read_hw(counter
, buf
, count
);
1291 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
1293 struct perf_counter
*counter
= file
->private_data
;
1294 struct perf_mmap_data
*data
;
1295 unsigned int events
= POLL_HUP
;
1298 data
= rcu_dereference(counter
->data
);
1300 events
= atomic_xchg(&data
->poll
, 0);
1303 poll_wait(file
, &counter
->waitq
, wait
);
1308 static void perf_counter_reset(struct perf_counter
*counter
)
1310 atomic_set(&counter
->count
, 0);
1313 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
1315 struct perf_counter
*counter
= file
->private_data
;
1319 case PERF_COUNTER_IOC_ENABLE
:
1320 perf_counter_enable_family(counter
);
1322 case PERF_COUNTER_IOC_DISABLE
:
1323 perf_counter_disable_family(counter
);
1325 case PERF_COUNTER_IOC_REFRESH
:
1326 err
= perf_counter_refresh(counter
, arg
);
1328 case PERF_COUNTER_IOC_RESET
:
1329 perf_counter_reset(counter
);
1338 * Callers need to ensure there can be no nesting of this function, otherwise
1339 * the seqlock logic goes bad. We can not serialize this because the arch
1340 * code calls this from NMI context.
1342 void perf_counter_update_userpage(struct perf_counter
*counter
)
1344 struct perf_mmap_data
*data
;
1345 struct perf_counter_mmap_page
*userpg
;
1348 data
= rcu_dereference(counter
->data
);
1352 userpg
= data
->user_page
;
1355 * Disable preemption so as to not let the corresponding user-space
1356 * spin too long if we get preempted.
1361 userpg
->index
= counter
->hw
.idx
;
1362 userpg
->offset
= atomic64_read(&counter
->count
);
1363 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
)
1364 userpg
->offset
-= atomic64_read(&counter
->hw
.prev_count
);
1373 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1375 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1376 struct perf_mmap_data
*data
;
1377 int ret
= VM_FAULT_SIGBUS
;
1380 data
= rcu_dereference(counter
->data
);
1384 if (vmf
->pgoff
== 0) {
1385 vmf
->page
= virt_to_page(data
->user_page
);
1387 int nr
= vmf
->pgoff
- 1;
1389 if ((unsigned)nr
> data
->nr_pages
)
1392 vmf
->page
= virt_to_page(data
->data_pages
[nr
]);
1394 get_page(vmf
->page
);
1402 static int perf_mmap_data_alloc(struct perf_counter
*counter
, int nr_pages
)
1404 struct perf_mmap_data
*data
;
1408 WARN_ON(atomic_read(&counter
->mmap_count
));
1410 size
= sizeof(struct perf_mmap_data
);
1411 size
+= nr_pages
* sizeof(void *);
1413 data
= kzalloc(size
, GFP_KERNEL
);
1417 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
1418 if (!data
->user_page
)
1419 goto fail_user_page
;
1421 for (i
= 0; i
< nr_pages
; i
++) {
1422 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
1423 if (!data
->data_pages
[i
])
1424 goto fail_data_pages
;
1427 data
->nr_pages
= nr_pages
;
1428 atomic_set(&data
->lock
, -1);
1430 rcu_assign_pointer(counter
->data
, data
);
1435 for (i
--; i
>= 0; i
--)
1436 free_page((unsigned long)data
->data_pages
[i
]);
1438 free_page((unsigned long)data
->user_page
);
1447 static void __perf_mmap_data_free(struct rcu_head
*rcu_head
)
1449 struct perf_mmap_data
*data
= container_of(rcu_head
,
1450 struct perf_mmap_data
, rcu_head
);
1453 free_page((unsigned long)data
->user_page
);
1454 for (i
= 0; i
< data
->nr_pages
; i
++)
1455 free_page((unsigned long)data
->data_pages
[i
]);
1459 static void perf_mmap_data_free(struct perf_counter
*counter
)
1461 struct perf_mmap_data
*data
= counter
->data
;
1463 WARN_ON(atomic_read(&counter
->mmap_count
));
1465 rcu_assign_pointer(counter
->data
, NULL
);
1466 call_rcu(&data
->rcu_head
, __perf_mmap_data_free
);
1469 static void perf_mmap_open(struct vm_area_struct
*vma
)
1471 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1473 atomic_inc(&counter
->mmap_count
);
1476 static void perf_mmap_close(struct vm_area_struct
*vma
)
1478 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1480 if (atomic_dec_and_mutex_lock(&counter
->mmap_count
,
1481 &counter
->mmap_mutex
)) {
1482 vma
->vm_mm
->locked_vm
-= counter
->data
->nr_locked
;
1483 perf_mmap_data_free(counter
);
1484 mutex_unlock(&counter
->mmap_mutex
);
1488 static struct vm_operations_struct perf_mmap_vmops
= {
1489 .open
= perf_mmap_open
,
1490 .close
= perf_mmap_close
,
1491 .fault
= perf_mmap_fault
,
1494 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1496 struct perf_counter
*counter
= file
->private_data
;
1497 unsigned long vma_size
;
1498 unsigned long nr_pages
;
1499 unsigned long locked
, lock_limit
;
1503 if (!(vma
->vm_flags
& VM_SHARED
) || (vma
->vm_flags
& VM_WRITE
))
1506 vma_size
= vma
->vm_end
- vma
->vm_start
;
1507 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
1510 * If we have data pages ensure they're a power-of-two number, so we
1511 * can do bitmasks instead of modulo.
1513 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
1516 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
1519 if (vma
->vm_pgoff
!= 0)
1522 mutex_lock(&counter
->mmap_mutex
);
1523 if (atomic_inc_not_zero(&counter
->mmap_count
)) {
1524 if (nr_pages
!= counter
->data
->nr_pages
)
1529 extra
= nr_pages
/* + 1 only account the data pages */;
1530 extra
-= sysctl_perf_counter_mlock
>> (PAGE_SHIFT
- 10);
1534 locked
= vma
->vm_mm
->locked_vm
+ extra
;
1536 lock_limit
= current
->signal
->rlim
[RLIMIT_MEMLOCK
].rlim_cur
;
1537 lock_limit
>>= PAGE_SHIFT
;
1539 if ((locked
> lock_limit
) && !capable(CAP_IPC_LOCK
)) {
1544 WARN_ON(counter
->data
);
1545 ret
= perf_mmap_data_alloc(counter
, nr_pages
);
1549 atomic_set(&counter
->mmap_count
, 1);
1550 vma
->vm_mm
->locked_vm
+= extra
;
1551 counter
->data
->nr_locked
= extra
;
1553 mutex_unlock(&counter
->mmap_mutex
);
1555 vma
->vm_flags
&= ~VM_MAYWRITE
;
1556 vma
->vm_flags
|= VM_RESERVED
;
1557 vma
->vm_ops
= &perf_mmap_vmops
;
1562 static int perf_fasync(int fd
, struct file
*filp
, int on
)
1564 struct perf_counter
*counter
= filp
->private_data
;
1565 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
1568 mutex_lock(&inode
->i_mutex
);
1569 retval
= fasync_helper(fd
, filp
, on
, &counter
->fasync
);
1570 mutex_unlock(&inode
->i_mutex
);
1578 static const struct file_operations perf_fops
= {
1579 .release
= perf_release
,
1582 .unlocked_ioctl
= perf_ioctl
,
1583 .compat_ioctl
= perf_ioctl
,
1585 .fasync
= perf_fasync
,
1589 * Perf counter wakeup
1591 * If there's data, ensure we set the poll() state and publish everything
1592 * to user-space before waking everybody up.
1595 void perf_counter_wakeup(struct perf_counter
*counter
)
1597 wake_up_all(&counter
->waitq
);
1599 if (counter
->pending_kill
) {
1600 kill_fasync(&counter
->fasync
, SIGIO
, counter
->pending_kill
);
1601 counter
->pending_kill
= 0;
1608 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
1610 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
1611 * single linked list and use cmpxchg() to add entries lockless.
1614 static void perf_pending_counter(struct perf_pending_entry
*entry
)
1616 struct perf_counter
*counter
= container_of(entry
,
1617 struct perf_counter
, pending
);
1619 if (counter
->pending_disable
) {
1620 counter
->pending_disable
= 0;
1621 perf_counter_disable(counter
);
1624 if (counter
->pending_wakeup
) {
1625 counter
->pending_wakeup
= 0;
1626 perf_counter_wakeup(counter
);
1630 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
1632 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
1636 static void perf_pending_queue(struct perf_pending_entry
*entry
,
1637 void (*func
)(struct perf_pending_entry
*))
1639 struct perf_pending_entry
**head
;
1641 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
1646 head
= &get_cpu_var(perf_pending_head
);
1649 entry
->next
= *head
;
1650 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
1652 set_perf_counter_pending();
1654 put_cpu_var(perf_pending_head
);
1657 static int __perf_pending_run(void)
1659 struct perf_pending_entry
*list
;
1662 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
1663 while (list
!= PENDING_TAIL
) {
1664 void (*func
)(struct perf_pending_entry
*);
1665 struct perf_pending_entry
*entry
= list
;
1672 * Ensure we observe the unqueue before we issue the wakeup,
1673 * so that we won't be waiting forever.
1674 * -- see perf_not_pending().
1685 static inline int perf_not_pending(struct perf_counter
*counter
)
1688 * If we flush on whatever cpu we run, there is a chance we don't
1692 __perf_pending_run();
1696 * Ensure we see the proper queue state before going to sleep
1697 * so that we do not miss the wakeup. -- see perf_pending_handle()
1700 return counter
->pending
.next
== NULL
;
1703 static void perf_pending_sync(struct perf_counter
*counter
)
1705 wait_event(counter
->waitq
, perf_not_pending(counter
));
1708 void perf_counter_do_pending(void)
1710 __perf_pending_run();
1714 * Callchain support -- arch specific
1717 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
1726 struct perf_output_handle
{
1727 struct perf_counter
*counter
;
1728 struct perf_mmap_data
*data
;
1729 unsigned int offset
;
1734 unsigned long flags
;
1737 static void perf_output_wakeup(struct perf_output_handle
*handle
)
1739 atomic_set(&handle
->data
->poll
, POLL_IN
);
1742 handle
->counter
->pending_wakeup
= 1;
1743 perf_pending_queue(&handle
->counter
->pending
,
1744 perf_pending_counter
);
1746 perf_counter_wakeup(handle
->counter
);
1750 * Curious locking construct.
1752 * We need to ensure a later event doesn't publish a head when a former
1753 * event isn't done writing. However since we need to deal with NMIs we
1754 * cannot fully serialize things.
1756 * What we do is serialize between CPUs so we only have to deal with NMI
1757 * nesting on a single CPU.
1759 * We only publish the head (and generate a wakeup) when the outer-most
1762 static void perf_output_lock(struct perf_output_handle
*handle
)
1764 struct perf_mmap_data
*data
= handle
->data
;
1769 local_irq_save(handle
->flags
);
1770 cpu
= smp_processor_id();
1772 if (in_nmi() && atomic_read(&data
->lock
) == cpu
)
1775 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
1781 static void perf_output_unlock(struct perf_output_handle
*handle
)
1783 struct perf_mmap_data
*data
= handle
->data
;
1786 data
->done_head
= data
->head
;
1788 if (!handle
->locked
)
1793 * The xchg implies a full barrier that ensures all writes are done
1794 * before we publish the new head, matched by a rmb() in userspace when
1795 * reading this position.
1797 while ((head
= atomic_xchg(&data
->done_head
, 0)))
1798 data
->user_page
->data_head
= head
;
1801 * NMI can happen here, which means we can miss a done_head update.
1804 cpu
= atomic_xchg(&data
->lock
, -1);
1805 WARN_ON_ONCE(cpu
!= smp_processor_id());
1808 * Therefore we have to validate we did not indeed do so.
1810 if (unlikely(atomic_read(&data
->done_head
))) {
1812 * Since we had it locked, we can lock it again.
1814 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
1820 if (atomic_xchg(&data
->wakeup
, 0))
1821 perf_output_wakeup(handle
);
1823 local_irq_restore(handle
->flags
);
1826 static int perf_output_begin(struct perf_output_handle
*handle
,
1827 struct perf_counter
*counter
, unsigned int size
,
1828 int nmi
, int overflow
)
1830 struct perf_mmap_data
*data
;
1831 unsigned int offset
, head
;
1834 * For inherited counters we send all the output towards the parent.
1836 if (counter
->parent
)
1837 counter
= counter
->parent
;
1840 data
= rcu_dereference(counter
->data
);
1844 handle
->data
= data
;
1845 handle
->counter
= counter
;
1847 handle
->overflow
= overflow
;
1849 if (!data
->nr_pages
)
1852 perf_output_lock(handle
);
1855 offset
= head
= atomic_read(&data
->head
);
1857 } while (atomic_cmpxchg(&data
->head
, offset
, head
) != offset
);
1859 handle
->offset
= offset
;
1860 handle
->head
= head
;
1862 if ((offset
>> PAGE_SHIFT
) != (head
>> PAGE_SHIFT
))
1863 atomic_set(&data
->wakeup
, 1);
1868 perf_output_wakeup(handle
);
1875 static void perf_output_copy(struct perf_output_handle
*handle
,
1876 void *buf
, unsigned int len
)
1878 unsigned int pages_mask
;
1879 unsigned int offset
;
1883 offset
= handle
->offset
;
1884 pages_mask
= handle
->data
->nr_pages
- 1;
1885 pages
= handle
->data
->data_pages
;
1888 unsigned int page_offset
;
1891 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
1892 page_offset
= offset
& (PAGE_SIZE
- 1);
1893 size
= min_t(unsigned int, PAGE_SIZE
- page_offset
, len
);
1895 memcpy(pages
[nr
] + page_offset
, buf
, size
);
1902 handle
->offset
= offset
;
1904 WARN_ON_ONCE(handle
->offset
> handle
->head
);
1907 #define perf_output_put(handle, x) \
1908 perf_output_copy((handle), &(x), sizeof(x))
1910 static void perf_output_end(struct perf_output_handle
*handle
)
1912 struct perf_counter
*counter
= handle
->counter
;
1913 struct perf_mmap_data
*data
= handle
->data
;
1915 int wakeup_events
= counter
->hw_event
.wakeup_events
;
1917 if (handle
->overflow
&& wakeup_events
) {
1918 int events
= atomic_inc_return(&data
->events
);
1919 if (events
>= wakeup_events
) {
1920 atomic_sub(wakeup_events
, &data
->events
);
1921 atomic_set(&data
->wakeup
, 1);
1925 perf_output_unlock(handle
);
1929 static void perf_counter_output(struct perf_counter
*counter
,
1930 int nmi
, struct pt_regs
*regs
, u64 addr
)
1933 u64 record_type
= counter
->hw_event
.record_type
;
1934 struct perf_output_handle handle
;
1935 struct perf_event_header header
;
1944 struct perf_callchain_entry
*callchain
= NULL
;
1945 int callchain_size
= 0;
1949 header
.size
= sizeof(header
);
1951 header
.misc
= PERF_EVENT_MISC_OVERFLOW
;
1952 header
.misc
|= user_mode(regs
) ?
1953 PERF_EVENT_MISC_USER
: PERF_EVENT_MISC_KERNEL
;
1955 if (record_type
& PERF_RECORD_IP
) {
1956 ip
= instruction_pointer(regs
);
1957 header
.type
|= PERF_RECORD_IP
;
1958 header
.size
+= sizeof(ip
);
1961 if (record_type
& PERF_RECORD_TID
) {
1962 /* namespace issues */
1963 tid_entry
.pid
= current
->group_leader
->pid
;
1964 tid_entry
.tid
= current
->pid
;
1966 header
.type
|= PERF_RECORD_TID
;
1967 header
.size
+= sizeof(tid_entry
);
1970 if (record_type
& PERF_RECORD_TIME
) {
1972 * Maybe do better on x86 and provide cpu_clock_nmi()
1974 time
= sched_clock();
1976 header
.type
|= PERF_RECORD_TIME
;
1977 header
.size
+= sizeof(u64
);
1980 if (record_type
& PERF_RECORD_ADDR
) {
1981 header
.type
|= PERF_RECORD_ADDR
;
1982 header
.size
+= sizeof(u64
);
1985 if (record_type
& PERF_RECORD_GROUP
) {
1986 header
.type
|= PERF_RECORD_GROUP
;
1987 header
.size
+= sizeof(u64
) +
1988 counter
->nr_siblings
* sizeof(group_entry
);
1991 if (record_type
& PERF_RECORD_CALLCHAIN
) {
1992 callchain
= perf_callchain(regs
);
1995 callchain_size
= (1 + callchain
->nr
) * sizeof(u64
);
1997 header
.type
|= PERF_RECORD_CALLCHAIN
;
1998 header
.size
+= callchain_size
;
2002 ret
= perf_output_begin(&handle
, counter
, header
.size
, nmi
, 1);
2006 perf_output_put(&handle
, header
);
2008 if (record_type
& PERF_RECORD_IP
)
2009 perf_output_put(&handle
, ip
);
2011 if (record_type
& PERF_RECORD_TID
)
2012 perf_output_put(&handle
, tid_entry
);
2014 if (record_type
& PERF_RECORD_TIME
)
2015 perf_output_put(&handle
, time
);
2017 if (record_type
& PERF_RECORD_ADDR
)
2018 perf_output_put(&handle
, addr
);
2021 * XXX PERF_RECORD_GROUP vs inherited counters seems difficult.
2023 if (record_type
& PERF_RECORD_GROUP
) {
2024 struct perf_counter
*leader
, *sub
;
2025 u64 nr
= counter
->nr_siblings
;
2027 perf_output_put(&handle
, nr
);
2029 leader
= counter
->group_leader
;
2030 list_for_each_entry(sub
, &leader
->sibling_list
, list_entry
) {
2032 sub
->pmu
->read(sub
);
2034 group_entry
.event
= sub
->hw_event
.config
;
2035 group_entry
.counter
= atomic64_read(&sub
->count
);
2037 perf_output_put(&handle
, group_entry
);
2042 perf_output_copy(&handle
, callchain
, callchain_size
);
2044 perf_output_end(&handle
);
2051 struct perf_comm_event
{
2052 struct task_struct
*task
;
2057 struct perf_event_header header
;
2064 static void perf_counter_comm_output(struct perf_counter
*counter
,
2065 struct perf_comm_event
*comm_event
)
2067 struct perf_output_handle handle
;
2068 int size
= comm_event
->event
.header
.size
;
2069 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
2074 perf_output_put(&handle
, comm_event
->event
);
2075 perf_output_copy(&handle
, comm_event
->comm
,
2076 comm_event
->comm_size
);
2077 perf_output_end(&handle
);
2080 static int perf_counter_comm_match(struct perf_counter
*counter
,
2081 struct perf_comm_event
*comm_event
)
2083 if (counter
->hw_event
.comm
&&
2084 comm_event
->event
.header
.type
== PERF_EVENT_COMM
)
2090 static void perf_counter_comm_ctx(struct perf_counter_context
*ctx
,
2091 struct perf_comm_event
*comm_event
)
2093 struct perf_counter
*counter
;
2095 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2099 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2100 if (perf_counter_comm_match(counter
, comm_event
))
2101 perf_counter_comm_output(counter
, comm_event
);
2106 static void perf_counter_comm_event(struct perf_comm_event
*comm_event
)
2108 struct perf_cpu_context
*cpuctx
;
2110 char *comm
= comm_event
->task
->comm
;
2112 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
2114 comm_event
->comm
= comm
;
2115 comm_event
->comm_size
= size
;
2117 comm_event
->event
.header
.size
= sizeof(comm_event
->event
) + size
;
2119 cpuctx
= &get_cpu_var(perf_cpu_context
);
2120 perf_counter_comm_ctx(&cpuctx
->ctx
, comm_event
);
2121 put_cpu_var(perf_cpu_context
);
2123 perf_counter_comm_ctx(¤t
->perf_counter_ctx
, comm_event
);
2126 void perf_counter_comm(struct task_struct
*task
)
2128 struct perf_comm_event comm_event
;
2130 if (!atomic_read(&nr_comm_tracking
))
2133 comm_event
= (struct perf_comm_event
){
2136 .header
= { .type
= PERF_EVENT_COMM
, },
2137 .pid
= task
->group_leader
->pid
,
2142 perf_counter_comm_event(&comm_event
);
2149 struct perf_mmap_event
{
2155 struct perf_event_header header
;
2165 static void perf_counter_mmap_output(struct perf_counter
*counter
,
2166 struct perf_mmap_event
*mmap_event
)
2168 struct perf_output_handle handle
;
2169 int size
= mmap_event
->event
.header
.size
;
2170 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
2175 perf_output_put(&handle
, mmap_event
->event
);
2176 perf_output_copy(&handle
, mmap_event
->file_name
,
2177 mmap_event
->file_size
);
2178 perf_output_end(&handle
);
2181 static int perf_counter_mmap_match(struct perf_counter
*counter
,
2182 struct perf_mmap_event
*mmap_event
)
2184 if (counter
->hw_event
.mmap
&&
2185 mmap_event
->event
.header
.type
== PERF_EVENT_MMAP
)
2188 if (counter
->hw_event
.munmap
&&
2189 mmap_event
->event
.header
.type
== PERF_EVENT_MUNMAP
)
2195 static void perf_counter_mmap_ctx(struct perf_counter_context
*ctx
,
2196 struct perf_mmap_event
*mmap_event
)
2198 struct perf_counter
*counter
;
2200 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2204 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2205 if (perf_counter_mmap_match(counter
, mmap_event
))
2206 perf_counter_mmap_output(counter
, mmap_event
);
2211 static void perf_counter_mmap_event(struct perf_mmap_event
*mmap_event
)
2213 struct perf_cpu_context
*cpuctx
;
2214 struct file
*file
= mmap_event
->file
;
2221 buf
= kzalloc(PATH_MAX
, GFP_KERNEL
);
2223 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
2226 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
2228 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
2232 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
2237 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
2239 mmap_event
->file_name
= name
;
2240 mmap_event
->file_size
= size
;
2242 mmap_event
->event
.header
.size
= sizeof(mmap_event
->event
) + size
;
2244 cpuctx
= &get_cpu_var(perf_cpu_context
);
2245 perf_counter_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
2246 put_cpu_var(perf_cpu_context
);
2248 perf_counter_mmap_ctx(¤t
->perf_counter_ctx
, mmap_event
);
2253 void perf_counter_mmap(unsigned long addr
, unsigned long len
,
2254 unsigned long pgoff
, struct file
*file
)
2256 struct perf_mmap_event mmap_event
;
2258 if (!atomic_read(&nr_mmap_tracking
))
2261 mmap_event
= (struct perf_mmap_event
){
2264 .header
= { .type
= PERF_EVENT_MMAP
, },
2265 .pid
= current
->group_leader
->pid
,
2266 .tid
= current
->pid
,
2273 perf_counter_mmap_event(&mmap_event
);
2276 void perf_counter_munmap(unsigned long addr
, unsigned long len
,
2277 unsigned long pgoff
, struct file
*file
)
2279 struct perf_mmap_event mmap_event
;
2281 if (!atomic_read(&nr_munmap_tracking
))
2284 mmap_event
= (struct perf_mmap_event
){
2287 .header
= { .type
= PERF_EVENT_MUNMAP
, },
2288 .pid
= current
->group_leader
->pid
,
2289 .tid
= current
->pid
,
2296 perf_counter_mmap_event(&mmap_event
);
2300 * Generic counter overflow handling.
2303 int perf_counter_overflow(struct perf_counter
*counter
,
2304 int nmi
, struct pt_regs
*regs
, u64 addr
)
2306 int events
= atomic_read(&counter
->event_limit
);
2310 * XXX event_limit might not quite work as expected on inherited
2314 counter
->pending_kill
= POLL_IN
;
2315 if (events
&& atomic_dec_and_test(&counter
->event_limit
)) {
2317 counter
->pending_kill
= POLL_HUP
;
2319 counter
->pending_disable
= 1;
2320 perf_pending_queue(&counter
->pending
,
2321 perf_pending_counter
);
2323 perf_counter_disable(counter
);
2326 perf_counter_output(counter
, nmi
, regs
, addr
);
2331 * Generic software counter infrastructure
2334 static void perf_swcounter_update(struct perf_counter
*counter
)
2336 struct hw_perf_counter
*hwc
= &counter
->hw
;
2341 prev
= atomic64_read(&hwc
->prev_count
);
2342 now
= atomic64_read(&hwc
->count
);
2343 if (atomic64_cmpxchg(&hwc
->prev_count
, prev
, now
) != prev
)
2348 atomic64_add(delta
, &counter
->count
);
2349 atomic64_sub(delta
, &hwc
->period_left
);
2352 static void perf_swcounter_set_period(struct perf_counter
*counter
)
2354 struct hw_perf_counter
*hwc
= &counter
->hw
;
2355 s64 left
= atomic64_read(&hwc
->period_left
);
2356 s64 period
= hwc
->irq_period
;
2358 if (unlikely(left
<= -period
)) {
2360 atomic64_set(&hwc
->period_left
, left
);
2363 if (unlikely(left
<= 0)) {
2365 atomic64_add(period
, &hwc
->period_left
);
2368 atomic64_set(&hwc
->prev_count
, -left
);
2369 atomic64_set(&hwc
->count
, -left
);
2372 static enum hrtimer_restart
perf_swcounter_hrtimer(struct hrtimer
*hrtimer
)
2374 enum hrtimer_restart ret
= HRTIMER_RESTART
;
2375 struct perf_counter
*counter
;
2376 struct pt_regs
*regs
;
2378 counter
= container_of(hrtimer
, struct perf_counter
, hw
.hrtimer
);
2379 counter
->pmu
->read(counter
);
2381 regs
= get_irq_regs();
2383 * In case we exclude kernel IPs or are somehow not in interrupt
2384 * context, provide the next best thing, the user IP.
2386 if ((counter
->hw_event
.exclude_kernel
|| !regs
) &&
2387 !counter
->hw_event
.exclude_user
)
2388 regs
= task_pt_regs(current
);
2391 if (perf_counter_overflow(counter
, 0, regs
, 0))
2392 ret
= HRTIMER_NORESTART
;
2395 hrtimer_forward_now(hrtimer
, ns_to_ktime(counter
->hw
.irq_period
));
2400 static void perf_swcounter_overflow(struct perf_counter
*counter
,
2401 int nmi
, struct pt_regs
*regs
, u64 addr
)
2403 perf_swcounter_update(counter
);
2404 perf_swcounter_set_period(counter
);
2405 if (perf_counter_overflow(counter
, nmi
, regs
, addr
))
2406 /* soft-disable the counter */
2411 static int perf_swcounter_match(struct perf_counter
*counter
,
2412 enum perf_event_types type
,
2413 u32 event
, struct pt_regs
*regs
)
2415 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
2418 if (perf_event_raw(&counter
->hw_event
))
2421 if (perf_event_type(&counter
->hw_event
) != type
)
2424 if (perf_event_id(&counter
->hw_event
) != event
)
2427 if (counter
->hw_event
.exclude_user
&& user_mode(regs
))
2430 if (counter
->hw_event
.exclude_kernel
&& !user_mode(regs
))
2436 static void perf_swcounter_add(struct perf_counter
*counter
, u64 nr
,
2437 int nmi
, struct pt_regs
*regs
, u64 addr
)
2439 int neg
= atomic64_add_negative(nr
, &counter
->hw
.count
);
2440 if (counter
->hw
.irq_period
&& !neg
)
2441 perf_swcounter_overflow(counter
, nmi
, regs
, addr
);
2444 static void perf_swcounter_ctx_event(struct perf_counter_context
*ctx
,
2445 enum perf_event_types type
, u32 event
,
2446 u64 nr
, int nmi
, struct pt_regs
*regs
,
2449 struct perf_counter
*counter
;
2451 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2455 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2456 if (perf_swcounter_match(counter
, type
, event
, regs
))
2457 perf_swcounter_add(counter
, nr
, nmi
, regs
, addr
);
2462 static int *perf_swcounter_recursion_context(struct perf_cpu_context
*cpuctx
)
2465 return &cpuctx
->recursion
[3];
2468 return &cpuctx
->recursion
[2];
2471 return &cpuctx
->recursion
[1];
2473 return &cpuctx
->recursion
[0];
2476 static void __perf_swcounter_event(enum perf_event_types type
, u32 event
,
2477 u64 nr
, int nmi
, struct pt_regs
*regs
,
2480 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
2481 int *recursion
= perf_swcounter_recursion_context(cpuctx
);
2489 perf_swcounter_ctx_event(&cpuctx
->ctx
, type
, event
,
2490 nr
, nmi
, regs
, addr
);
2491 if (cpuctx
->task_ctx
) {
2492 perf_swcounter_ctx_event(cpuctx
->task_ctx
, type
, event
,
2493 nr
, nmi
, regs
, addr
);
2500 put_cpu_var(perf_cpu_context
);
2504 perf_swcounter_event(u32 event
, u64 nr
, int nmi
, struct pt_regs
*regs
, u64 addr
)
2506 __perf_swcounter_event(PERF_TYPE_SOFTWARE
, event
, nr
, nmi
, regs
, addr
);
2509 static void perf_swcounter_read(struct perf_counter
*counter
)
2511 perf_swcounter_update(counter
);
2514 static int perf_swcounter_enable(struct perf_counter
*counter
)
2516 perf_swcounter_set_period(counter
);
2520 static void perf_swcounter_disable(struct perf_counter
*counter
)
2522 perf_swcounter_update(counter
);
2525 static const struct pmu perf_ops_generic
= {
2526 .enable
= perf_swcounter_enable
,
2527 .disable
= perf_swcounter_disable
,
2528 .read
= perf_swcounter_read
,
2532 * Software counter: cpu wall time clock
2535 static void cpu_clock_perf_counter_update(struct perf_counter
*counter
)
2537 int cpu
= raw_smp_processor_id();
2541 now
= cpu_clock(cpu
);
2542 prev
= atomic64_read(&counter
->hw
.prev_count
);
2543 atomic64_set(&counter
->hw
.prev_count
, now
);
2544 atomic64_add(now
- prev
, &counter
->count
);
2547 static int cpu_clock_perf_counter_enable(struct perf_counter
*counter
)
2549 struct hw_perf_counter
*hwc
= &counter
->hw
;
2550 int cpu
= raw_smp_processor_id();
2552 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
2553 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2554 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2555 if (hwc
->irq_period
) {
2556 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2557 ns_to_ktime(hwc
->irq_period
), 0,
2558 HRTIMER_MODE_REL
, 0);
2564 static void cpu_clock_perf_counter_disable(struct perf_counter
*counter
)
2566 hrtimer_cancel(&counter
->hw
.hrtimer
);
2567 cpu_clock_perf_counter_update(counter
);
2570 static void cpu_clock_perf_counter_read(struct perf_counter
*counter
)
2572 cpu_clock_perf_counter_update(counter
);
2575 static const struct pmu perf_ops_cpu_clock
= {
2576 .enable
= cpu_clock_perf_counter_enable
,
2577 .disable
= cpu_clock_perf_counter_disable
,
2578 .read
= cpu_clock_perf_counter_read
,
2582 * Software counter: task time clock
2585 static void task_clock_perf_counter_update(struct perf_counter
*counter
, u64 now
)
2590 prev
= atomic64_xchg(&counter
->hw
.prev_count
, now
);
2592 atomic64_add(delta
, &counter
->count
);
2595 static int task_clock_perf_counter_enable(struct perf_counter
*counter
)
2597 struct hw_perf_counter
*hwc
= &counter
->hw
;
2600 now
= counter
->ctx
->time
;
2602 atomic64_set(&hwc
->prev_count
, now
);
2603 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2604 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2605 if (hwc
->irq_period
) {
2606 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2607 ns_to_ktime(hwc
->irq_period
), 0,
2608 HRTIMER_MODE_REL
, 0);
2614 static void task_clock_perf_counter_disable(struct perf_counter
*counter
)
2616 hrtimer_cancel(&counter
->hw
.hrtimer
);
2617 task_clock_perf_counter_update(counter
, counter
->ctx
->time
);
2621 static void task_clock_perf_counter_read(struct perf_counter
*counter
)
2626 update_context_time(counter
->ctx
);
2627 time
= counter
->ctx
->time
;
2629 u64 now
= perf_clock();
2630 u64 delta
= now
- counter
->ctx
->timestamp
;
2631 time
= counter
->ctx
->time
+ delta
;
2634 task_clock_perf_counter_update(counter
, time
);
2637 static const struct pmu perf_ops_task_clock
= {
2638 .enable
= task_clock_perf_counter_enable
,
2639 .disable
= task_clock_perf_counter_disable
,
2640 .read
= task_clock_perf_counter_read
,
2644 * Software counter: cpu migrations
2647 static inline u64
get_cpu_migrations(struct perf_counter
*counter
)
2649 struct task_struct
*curr
= counter
->ctx
->task
;
2652 return curr
->se
.nr_migrations
;
2653 return cpu_nr_migrations(smp_processor_id());
2656 static void cpu_migrations_perf_counter_update(struct perf_counter
*counter
)
2661 prev
= atomic64_read(&counter
->hw
.prev_count
);
2662 now
= get_cpu_migrations(counter
);
2664 atomic64_set(&counter
->hw
.prev_count
, now
);
2668 atomic64_add(delta
, &counter
->count
);
2671 static void cpu_migrations_perf_counter_read(struct perf_counter
*counter
)
2673 cpu_migrations_perf_counter_update(counter
);
2676 static int cpu_migrations_perf_counter_enable(struct perf_counter
*counter
)
2678 if (counter
->prev_state
<= PERF_COUNTER_STATE_OFF
)
2679 atomic64_set(&counter
->hw
.prev_count
,
2680 get_cpu_migrations(counter
));
2684 static void cpu_migrations_perf_counter_disable(struct perf_counter
*counter
)
2686 cpu_migrations_perf_counter_update(counter
);
2689 static const struct pmu perf_ops_cpu_migrations
= {
2690 .enable
= cpu_migrations_perf_counter_enable
,
2691 .disable
= cpu_migrations_perf_counter_disable
,
2692 .read
= cpu_migrations_perf_counter_read
,
2695 #ifdef CONFIG_EVENT_PROFILE
2696 void perf_tpcounter_event(int event_id
)
2698 struct pt_regs
*regs
= get_irq_regs();
2701 regs
= task_pt_regs(current
);
2703 __perf_swcounter_event(PERF_TYPE_TRACEPOINT
, event_id
, 1, 1, regs
, 0);
2705 EXPORT_SYMBOL_GPL(perf_tpcounter_event
);
2707 extern int ftrace_profile_enable(int);
2708 extern void ftrace_profile_disable(int);
2710 static void tp_perf_counter_destroy(struct perf_counter
*counter
)
2712 ftrace_profile_disable(perf_event_id(&counter
->hw_event
));
2715 static const struct pmu
*tp_perf_counter_init(struct perf_counter
*counter
)
2717 int event_id
= perf_event_id(&counter
->hw_event
);
2720 ret
= ftrace_profile_enable(event_id
);
2724 counter
->destroy
= tp_perf_counter_destroy
;
2725 counter
->hw
.irq_period
= counter
->hw_event
.irq_period
;
2727 return &perf_ops_generic
;
2730 static const struct pmu
*tp_perf_counter_init(struct perf_counter
*counter
)
2736 static const struct pmu
*sw_perf_counter_init(struct perf_counter
*counter
)
2738 struct perf_counter_hw_event
*hw_event
= &counter
->hw_event
;
2739 const struct pmu
*pmu
= NULL
;
2740 struct hw_perf_counter
*hwc
= &counter
->hw
;
2743 * Software counters (currently) can't in general distinguish
2744 * between user, kernel and hypervisor events.
2745 * However, context switches and cpu migrations are considered
2746 * to be kernel events, and page faults are never hypervisor
2749 switch (perf_event_id(&counter
->hw_event
)) {
2750 case PERF_COUNT_CPU_CLOCK
:
2751 pmu
= &perf_ops_cpu_clock
;
2753 if (hw_event
->irq_period
&& hw_event
->irq_period
< 10000)
2754 hw_event
->irq_period
= 10000;
2756 case PERF_COUNT_TASK_CLOCK
:
2758 * If the user instantiates this as a per-cpu counter,
2759 * use the cpu_clock counter instead.
2761 if (counter
->ctx
->task
)
2762 pmu
= &perf_ops_task_clock
;
2764 pmu
= &perf_ops_cpu_clock
;
2766 if (hw_event
->irq_period
&& hw_event
->irq_period
< 10000)
2767 hw_event
->irq_period
= 10000;
2769 case PERF_COUNT_PAGE_FAULTS
:
2770 case PERF_COUNT_PAGE_FAULTS_MIN
:
2771 case PERF_COUNT_PAGE_FAULTS_MAJ
:
2772 case PERF_COUNT_CONTEXT_SWITCHES
:
2773 pmu
= &perf_ops_generic
;
2775 case PERF_COUNT_CPU_MIGRATIONS
:
2776 if (!counter
->hw_event
.exclude_kernel
)
2777 pmu
= &perf_ops_cpu_migrations
;
2782 hwc
->irq_period
= hw_event
->irq_period
;
2788 * Allocate and initialize a counter structure
2790 static struct perf_counter
*
2791 perf_counter_alloc(struct perf_counter_hw_event
*hw_event
,
2793 struct perf_counter_context
*ctx
,
2794 struct perf_counter
*group_leader
,
2797 const struct pmu
*pmu
;
2798 struct perf_counter
*counter
;
2801 counter
= kzalloc(sizeof(*counter
), gfpflags
);
2803 return ERR_PTR(-ENOMEM
);
2806 * Single counters are their own group leaders, with an
2807 * empty sibling list:
2810 group_leader
= counter
;
2812 mutex_init(&counter
->mutex
);
2813 INIT_LIST_HEAD(&counter
->list_entry
);
2814 INIT_LIST_HEAD(&counter
->event_entry
);
2815 INIT_LIST_HEAD(&counter
->sibling_list
);
2816 init_waitqueue_head(&counter
->waitq
);
2818 mutex_init(&counter
->mmap_mutex
);
2820 INIT_LIST_HEAD(&counter
->child_list
);
2823 counter
->hw_event
= *hw_event
;
2824 counter
->group_leader
= group_leader
;
2825 counter
->pmu
= NULL
;
2828 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
2829 if (hw_event
->disabled
)
2830 counter
->state
= PERF_COUNTER_STATE_OFF
;
2835 * we currently do not support PERF_RECORD_GROUP on inherited counters
2837 if (hw_event
->inherit
&& (hw_event
->record_type
& PERF_RECORD_GROUP
))
2840 if (perf_event_raw(hw_event
)) {
2841 pmu
= hw_perf_counter_init(counter
);
2845 switch (perf_event_type(hw_event
)) {
2846 case PERF_TYPE_HARDWARE
:
2847 pmu
= hw_perf_counter_init(counter
);
2850 case PERF_TYPE_SOFTWARE
:
2851 pmu
= sw_perf_counter_init(counter
);
2854 case PERF_TYPE_TRACEPOINT
:
2855 pmu
= tp_perf_counter_init(counter
);
2862 else if (IS_ERR(pmu
))
2867 return ERR_PTR(err
);
2872 atomic_inc(&nr_counters
);
2873 if (counter
->hw_event
.mmap
)
2874 atomic_inc(&nr_mmap_tracking
);
2875 if (counter
->hw_event
.munmap
)
2876 atomic_inc(&nr_munmap_tracking
);
2877 if (counter
->hw_event
.comm
)
2878 atomic_inc(&nr_comm_tracking
);
2884 * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
2886 * @hw_event_uptr: event type attributes for monitoring/sampling
2889 * @group_fd: group leader counter fd
2891 SYSCALL_DEFINE5(perf_counter_open
,
2892 const struct perf_counter_hw_event __user
*, hw_event_uptr
,
2893 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
2895 struct perf_counter
*counter
, *group_leader
;
2896 struct perf_counter_hw_event hw_event
;
2897 struct perf_counter_context
*ctx
;
2898 struct file
*counter_file
= NULL
;
2899 struct file
*group_file
= NULL
;
2900 int fput_needed
= 0;
2901 int fput_needed2
= 0;
2904 /* for future expandability... */
2908 if (copy_from_user(&hw_event
, hw_event_uptr
, sizeof(hw_event
)) != 0)
2912 * Get the target context (task or percpu):
2914 ctx
= find_get_context(pid
, cpu
);
2916 return PTR_ERR(ctx
);
2919 * Look up the group leader (we will attach this counter to it):
2921 group_leader
= NULL
;
2922 if (group_fd
!= -1) {
2924 group_file
= fget_light(group_fd
, &fput_needed
);
2926 goto err_put_context
;
2927 if (group_file
->f_op
!= &perf_fops
)
2928 goto err_put_context
;
2930 group_leader
= group_file
->private_data
;
2932 * Do not allow a recursive hierarchy (this new sibling
2933 * becoming part of another group-sibling):
2935 if (group_leader
->group_leader
!= group_leader
)
2936 goto err_put_context
;
2938 * Do not allow to attach to a group in a different
2939 * task or CPU context:
2941 if (group_leader
->ctx
!= ctx
)
2942 goto err_put_context
;
2944 * Only a group leader can be exclusive or pinned
2946 if (hw_event
.exclusive
|| hw_event
.pinned
)
2947 goto err_put_context
;
2950 counter
= perf_counter_alloc(&hw_event
, cpu
, ctx
, group_leader
,
2952 ret
= PTR_ERR(counter
);
2953 if (IS_ERR(counter
))
2954 goto err_put_context
;
2956 ret
= anon_inode_getfd("[perf_counter]", &perf_fops
, counter
, 0);
2958 goto err_free_put_context
;
2960 counter_file
= fget_light(ret
, &fput_needed2
);
2962 goto err_free_put_context
;
2964 counter
->filp
= counter_file
;
2965 mutex_lock(&ctx
->mutex
);
2966 perf_install_in_context(ctx
, counter
, cpu
);
2967 mutex_unlock(&ctx
->mutex
);
2969 fput_light(counter_file
, fput_needed2
);
2972 fput_light(group_file
, fput_needed
);
2976 err_free_put_context
:
2986 * Initialize the perf_counter context in a task_struct:
2989 __perf_counter_init_context(struct perf_counter_context
*ctx
,
2990 struct task_struct
*task
)
2992 memset(ctx
, 0, sizeof(*ctx
));
2993 spin_lock_init(&ctx
->lock
);
2994 mutex_init(&ctx
->mutex
);
2995 INIT_LIST_HEAD(&ctx
->counter_list
);
2996 INIT_LIST_HEAD(&ctx
->event_list
);
3001 * inherit a counter from parent task to child task:
3003 static struct perf_counter
*
3004 inherit_counter(struct perf_counter
*parent_counter
,
3005 struct task_struct
*parent
,
3006 struct perf_counter_context
*parent_ctx
,
3007 struct task_struct
*child
,
3008 struct perf_counter
*group_leader
,
3009 struct perf_counter_context
*child_ctx
)
3011 struct perf_counter
*child_counter
;
3014 * Instead of creating recursive hierarchies of counters,
3015 * we link inherited counters back to the original parent,
3016 * which has a filp for sure, which we use as the reference
3019 if (parent_counter
->parent
)
3020 parent_counter
= parent_counter
->parent
;
3022 child_counter
= perf_counter_alloc(&parent_counter
->hw_event
,
3023 parent_counter
->cpu
, child_ctx
,
3024 group_leader
, GFP_KERNEL
);
3025 if (IS_ERR(child_counter
))
3026 return child_counter
;
3029 * Link it up in the child's context:
3031 child_counter
->task
= child
;
3032 add_counter_to_ctx(child_counter
, child_ctx
);
3034 child_counter
->parent
= parent_counter
;
3036 * inherit into child's child as well:
3038 child_counter
->hw_event
.inherit
= 1;
3041 * Get a reference to the parent filp - we will fput it
3042 * when the child counter exits. This is safe to do because
3043 * we are in the parent and we know that the filp still
3044 * exists and has a nonzero count:
3046 atomic_long_inc(&parent_counter
->filp
->f_count
);
3049 * Link this into the parent counter's child list
3051 mutex_lock(&parent_counter
->mutex
);
3052 list_add_tail(&child_counter
->child_list
, &parent_counter
->child_list
);
3055 * Make the child state follow the state of the parent counter,
3056 * not its hw_event.disabled bit. We hold the parent's mutex,
3057 * so we won't race with perf_counter_{en,dis}able_family.
3059 if (parent_counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
3060 child_counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
3062 child_counter
->state
= PERF_COUNTER_STATE_OFF
;
3064 mutex_unlock(&parent_counter
->mutex
);
3066 return child_counter
;
3069 static int inherit_group(struct perf_counter
*parent_counter
,
3070 struct task_struct
*parent
,
3071 struct perf_counter_context
*parent_ctx
,
3072 struct task_struct
*child
,
3073 struct perf_counter_context
*child_ctx
)
3075 struct perf_counter
*leader
;
3076 struct perf_counter
*sub
;
3077 struct perf_counter
*child_ctr
;
3079 leader
= inherit_counter(parent_counter
, parent
, parent_ctx
,
3080 child
, NULL
, child_ctx
);
3082 return PTR_ERR(leader
);
3083 list_for_each_entry(sub
, &parent_counter
->sibling_list
, list_entry
) {
3084 child_ctr
= inherit_counter(sub
, parent
, parent_ctx
,
3085 child
, leader
, child_ctx
);
3086 if (IS_ERR(child_ctr
))
3087 return PTR_ERR(child_ctr
);
3092 static void sync_child_counter(struct perf_counter
*child_counter
,
3093 struct perf_counter
*parent_counter
)
3095 u64 parent_val
, child_val
;
3097 parent_val
= atomic64_read(&parent_counter
->count
);
3098 child_val
= atomic64_read(&child_counter
->count
);
3101 * Add back the child's count to the parent's count:
3103 atomic64_add(child_val
, &parent_counter
->count
);
3104 atomic64_add(child_counter
->total_time_enabled
,
3105 &parent_counter
->child_total_time_enabled
);
3106 atomic64_add(child_counter
->total_time_running
,
3107 &parent_counter
->child_total_time_running
);
3110 * Remove this counter from the parent's list
3112 mutex_lock(&parent_counter
->mutex
);
3113 list_del_init(&child_counter
->child_list
);
3114 mutex_unlock(&parent_counter
->mutex
);
3117 * Release the parent counter, if this was the last
3120 fput(parent_counter
->filp
);
3124 __perf_counter_exit_task(struct task_struct
*child
,
3125 struct perf_counter
*child_counter
,
3126 struct perf_counter_context
*child_ctx
)
3128 struct perf_counter
*parent_counter
;
3129 struct perf_counter
*sub
, *tmp
;
3132 * If we do not self-reap then we have to wait for the
3133 * child task to unschedule (it will happen for sure),
3134 * so that its counter is at its final count. (This
3135 * condition triggers rarely - child tasks usually get
3136 * off their CPU before the parent has a chance to
3137 * get this far into the reaping action)
3139 if (child
!= current
) {
3140 wait_task_inactive(child
, 0);
3141 list_del_init(&child_counter
->list_entry
);
3142 update_counter_times(child_counter
);
3144 struct perf_cpu_context
*cpuctx
;
3145 unsigned long flags
;
3149 * Disable and unlink this counter.
3151 * Be careful about zapping the list - IRQ/NMI context
3152 * could still be processing it:
3154 local_irq_save(flags
);
3155 perf_flags
= hw_perf_save_disable();
3157 cpuctx
= &__get_cpu_var(perf_cpu_context
);
3159 group_sched_out(child_counter
, cpuctx
, child_ctx
);
3160 update_counter_times(child_counter
);
3162 list_del_init(&child_counter
->list_entry
);
3164 child_ctx
->nr_counters
--;
3166 hw_perf_restore(perf_flags
);
3167 local_irq_restore(flags
);
3170 parent_counter
= child_counter
->parent
;
3172 * It can happen that parent exits first, and has counters
3173 * that are still around due to the child reference. These
3174 * counters need to be zapped - but otherwise linger.
3176 if (parent_counter
) {
3177 sync_child_counter(child_counter
, parent_counter
);
3178 list_for_each_entry_safe(sub
, tmp
, &child_counter
->sibling_list
,
3181 sync_child_counter(sub
, sub
->parent
);
3185 free_counter(child_counter
);
3190 * When a child task exits, feed back counter values to parent counters.
3192 * Note: we may be running in child context, but the PID is not hashed
3193 * anymore so new counters will not be added.
3195 void perf_counter_exit_task(struct task_struct
*child
)
3197 struct perf_counter
*child_counter
, *tmp
;
3198 struct perf_counter_context
*child_ctx
;
3200 child_ctx
= &child
->perf_counter_ctx
;
3202 if (likely(!child_ctx
->nr_counters
))
3205 list_for_each_entry_safe(child_counter
, tmp
, &child_ctx
->counter_list
,
3207 __perf_counter_exit_task(child
, child_counter
, child_ctx
);
3211 * Initialize the perf_counter context in task_struct
3213 void perf_counter_init_task(struct task_struct
*child
)
3215 struct perf_counter_context
*child_ctx
, *parent_ctx
;
3216 struct perf_counter
*counter
;
3217 struct task_struct
*parent
= current
;
3219 child_ctx
= &child
->perf_counter_ctx
;
3220 parent_ctx
= &parent
->perf_counter_ctx
;
3222 __perf_counter_init_context(child_ctx
, child
);
3225 * This is executed from the parent task context, so inherit
3226 * counters that have been marked for cloning:
3229 if (likely(!parent_ctx
->nr_counters
))
3233 * Lock the parent list. No need to lock the child - not PID
3234 * hashed yet and not running, so nobody can access it.
3236 mutex_lock(&parent_ctx
->mutex
);
3239 * We dont have to disable NMIs - we are only looking at
3240 * the list, not manipulating it:
3242 list_for_each_entry(counter
, &parent_ctx
->counter_list
, list_entry
) {
3243 if (!counter
->hw_event
.inherit
)
3246 if (inherit_group(counter
, parent
,
3247 parent_ctx
, child
, child_ctx
))
3251 mutex_unlock(&parent_ctx
->mutex
);
3254 static void __cpuinit
perf_counter_init_cpu(int cpu
)
3256 struct perf_cpu_context
*cpuctx
;
3258 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3259 __perf_counter_init_context(&cpuctx
->ctx
, NULL
);
3261 spin_lock(&perf_resource_lock
);
3262 cpuctx
->max_pertask
= perf_max_counters
- perf_reserved_percpu
;
3263 spin_unlock(&perf_resource_lock
);
3265 hw_perf_counter_setup(cpu
);
3268 #ifdef CONFIG_HOTPLUG_CPU
3269 static void __perf_counter_exit_cpu(void *info
)
3271 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
3272 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3273 struct perf_counter
*counter
, *tmp
;
3275 list_for_each_entry_safe(counter
, tmp
, &ctx
->counter_list
, list_entry
)
3276 __perf_counter_remove_from_context(counter
);
3278 static void perf_counter_exit_cpu(int cpu
)
3280 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3281 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3283 mutex_lock(&ctx
->mutex
);
3284 smp_call_function_single(cpu
, __perf_counter_exit_cpu
, NULL
, 1);
3285 mutex_unlock(&ctx
->mutex
);
3288 static inline void perf_counter_exit_cpu(int cpu
) { }
3291 static int __cpuinit
3292 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
3294 unsigned int cpu
= (long)hcpu
;
3298 case CPU_UP_PREPARE
:
3299 case CPU_UP_PREPARE_FROZEN
:
3300 perf_counter_init_cpu(cpu
);
3303 case CPU_DOWN_PREPARE
:
3304 case CPU_DOWN_PREPARE_FROZEN
:
3305 perf_counter_exit_cpu(cpu
);
3315 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
3316 .notifier_call
= perf_cpu_notify
,
3319 void __init
perf_counter_init(void)
3321 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
3322 (void *)(long)smp_processor_id());
3323 register_cpu_notifier(&perf_cpu_nb
);
3326 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class, char *buf
)
3328 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
3332 perf_set_reserve_percpu(struct sysdev_class
*class,
3336 struct perf_cpu_context
*cpuctx
;
3340 err
= strict_strtoul(buf
, 10, &val
);
3343 if (val
> perf_max_counters
)
3346 spin_lock(&perf_resource_lock
);
3347 perf_reserved_percpu
= val
;
3348 for_each_online_cpu(cpu
) {
3349 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3350 spin_lock_irq(&cpuctx
->ctx
.lock
);
3351 mpt
= min(perf_max_counters
- cpuctx
->ctx
.nr_counters
,
3352 perf_max_counters
- perf_reserved_percpu
);
3353 cpuctx
->max_pertask
= mpt
;
3354 spin_unlock_irq(&cpuctx
->ctx
.lock
);
3356 spin_unlock(&perf_resource_lock
);
3361 static ssize_t
perf_show_overcommit(struct sysdev_class
*class, char *buf
)
3363 return sprintf(buf
, "%d\n", perf_overcommit
);
3367 perf_set_overcommit(struct sysdev_class
*class, const char *buf
, size_t count
)
3372 err
= strict_strtoul(buf
, 10, &val
);
3378 spin_lock(&perf_resource_lock
);
3379 perf_overcommit
= val
;
3380 spin_unlock(&perf_resource_lock
);
3385 static SYSDEV_CLASS_ATTR(
3388 perf_show_reserve_percpu
,
3389 perf_set_reserve_percpu
3392 static SYSDEV_CLASS_ATTR(
3395 perf_show_overcommit
,
3399 static struct attribute
*perfclass_attrs
[] = {
3400 &attr_reserve_percpu
.attr
,
3401 &attr_overcommit
.attr
,
3405 static struct attribute_group perfclass_attr_group
= {
3406 .attrs
= perfclass_attrs
,
3407 .name
= "perf_counters",
3410 static int __init
perf_counter_sysfs_init(void)
3412 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
3413 &perfclass_attr_group
);
3415 device_initcall(perf_counter_sysfs_init
);