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
= 512; /* 'free' kb per user */
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 void __weak
hw_perf_disable(void) { barrier(); }
64 void __weak
hw_perf_enable(void) { barrier(); }
66 void __weak
hw_perf_counter_setup(int cpu
) { barrier(); }
67 int __weak
hw_perf_group_sched_in(struct perf_counter
*group_leader
,
68 struct perf_cpu_context
*cpuctx
,
69 struct perf_counter_context
*ctx
, int cpu
)
74 void __weak
perf_counter_print_debug(void) { }
76 static DEFINE_PER_CPU(int, disable_count
);
78 void __perf_disable(void)
80 __get_cpu_var(disable_count
)++;
83 bool __perf_enable(void)
85 return !--__get_cpu_var(disable_count
);
88 void perf_disable(void)
94 void perf_enable(void)
100 static void get_ctx(struct perf_counter_context
*ctx
)
102 atomic_inc(&ctx
->refcount
);
105 static void put_ctx(struct perf_counter_context
*ctx
)
107 if (atomic_dec_and_test(&ctx
->refcount
)) {
109 put_ctx(ctx
->parent_ctx
);
115 list_add_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
117 struct perf_counter
*group_leader
= counter
->group_leader
;
120 * Depending on whether it is a standalone or sibling counter,
121 * add it straight to the context's counter list, or to the group
122 * leader's sibling list:
124 if (group_leader
== counter
)
125 list_add_tail(&counter
->list_entry
, &ctx
->counter_list
);
127 list_add_tail(&counter
->list_entry
, &group_leader
->sibling_list
);
128 group_leader
->nr_siblings
++;
131 list_add_rcu(&counter
->event_entry
, &ctx
->event_list
);
133 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
138 * Remove a counter from the lists for its context.
139 * Must be called with counter->mutex and ctx->mutex held.
142 list_del_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
144 struct perf_counter
*sibling
, *tmp
;
146 if (list_empty(&counter
->list_entry
))
149 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
152 list_del_init(&counter
->list_entry
);
153 list_del_rcu(&counter
->event_entry
);
155 if (counter
->group_leader
!= counter
)
156 counter
->group_leader
->nr_siblings
--;
159 * If this was a group counter with sibling counters then
160 * upgrade the siblings to singleton counters by adding them
161 * to the context list directly:
163 list_for_each_entry_safe(sibling
, tmp
,
164 &counter
->sibling_list
, list_entry
) {
166 list_move_tail(&sibling
->list_entry
, &ctx
->counter_list
);
167 sibling
->group_leader
= sibling
;
172 counter_sched_out(struct perf_counter
*counter
,
173 struct perf_cpu_context
*cpuctx
,
174 struct perf_counter_context
*ctx
)
176 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
179 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
180 counter
->tstamp_stopped
= ctx
->time
;
181 counter
->pmu
->disable(counter
);
184 if (!is_software_counter(counter
))
185 cpuctx
->active_oncpu
--;
187 if (counter
->hw_event
.exclusive
|| !cpuctx
->active_oncpu
)
188 cpuctx
->exclusive
= 0;
192 group_sched_out(struct perf_counter
*group_counter
,
193 struct perf_cpu_context
*cpuctx
,
194 struct perf_counter_context
*ctx
)
196 struct perf_counter
*counter
;
198 if (group_counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
201 counter_sched_out(group_counter
, cpuctx
, ctx
);
204 * Schedule out siblings (if any):
206 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
)
207 counter_sched_out(counter
, cpuctx
, ctx
);
209 if (group_counter
->hw_event
.exclusive
)
210 cpuctx
->exclusive
= 0;
214 * Mark this context as not being a clone of another.
215 * Called when counters are added to or removed from this context.
216 * We also increment our generation number so that anything that
217 * was cloned from this context before this will not match anything
218 * cloned from this context after this.
220 static void unclone_ctx(struct perf_counter_context
*ctx
)
223 if (!ctx
->parent_ctx
)
225 put_ctx(ctx
->parent_ctx
);
226 ctx
->parent_ctx
= NULL
;
230 * Cross CPU call to remove a performance counter
232 * We disable the counter on the hardware level first. After that we
233 * remove it from the context list.
235 static void __perf_counter_remove_from_context(void *info
)
237 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
238 struct perf_counter
*counter
= info
;
239 struct perf_counter_context
*ctx
= counter
->ctx
;
243 * If this is a task context, we need to check whether it is
244 * the current task context of this cpu. If not it has been
245 * scheduled out before the smp call arrived.
247 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
250 spin_lock_irqsave(&ctx
->lock
, flags
);
252 * Protect the list operation against NMI by disabling the
253 * counters on a global level.
257 counter_sched_out(counter
, cpuctx
, ctx
);
259 list_del_counter(counter
, ctx
);
263 * Allow more per task counters with respect to the
266 cpuctx
->max_pertask
=
267 min(perf_max_counters
- ctx
->nr_counters
,
268 perf_max_counters
- perf_reserved_percpu
);
272 spin_unlock_irqrestore(&ctx
->lock
, flags
);
277 * Remove the counter from a task's (or a CPU's) list of counters.
279 * Must be called with counter->mutex and ctx->mutex held.
281 * CPU counters are removed with a smp call. For task counters we only
282 * call when the task is on a CPU.
284 static void perf_counter_remove_from_context(struct perf_counter
*counter
)
286 struct perf_counter_context
*ctx
= counter
->ctx
;
287 struct task_struct
*task
= ctx
->task
;
292 * Per cpu counters are removed via an smp call and
293 * the removal is always sucessful.
295 smp_call_function_single(counter
->cpu
,
296 __perf_counter_remove_from_context
,
302 task_oncpu_function_call(task
, __perf_counter_remove_from_context
,
305 spin_lock_irq(&ctx
->lock
);
307 * If the context is active we need to retry the smp call.
309 if (ctx
->nr_active
&& !list_empty(&counter
->list_entry
)) {
310 spin_unlock_irq(&ctx
->lock
);
315 * The lock prevents that this context is scheduled in so we
316 * can remove the counter safely, if the call above did not
319 if (!list_empty(&counter
->list_entry
)) {
320 list_del_counter(counter
, ctx
);
322 spin_unlock_irq(&ctx
->lock
);
325 static inline u64
perf_clock(void)
327 return cpu_clock(smp_processor_id());
331 * Update the record of the current time in a context.
333 static void update_context_time(struct perf_counter_context
*ctx
)
335 u64 now
= perf_clock();
337 ctx
->time
+= now
- ctx
->timestamp
;
338 ctx
->timestamp
= now
;
342 * Update the total_time_enabled and total_time_running fields for a counter.
344 static void update_counter_times(struct perf_counter
*counter
)
346 struct perf_counter_context
*ctx
= counter
->ctx
;
349 if (counter
->state
< PERF_COUNTER_STATE_INACTIVE
)
352 counter
->total_time_enabled
= ctx
->time
- counter
->tstamp_enabled
;
354 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
)
355 run_end
= counter
->tstamp_stopped
;
359 counter
->total_time_running
= run_end
- counter
->tstamp_running
;
363 * Update total_time_enabled and total_time_running for all counters in a group.
365 static void update_group_times(struct perf_counter
*leader
)
367 struct perf_counter
*counter
;
369 update_counter_times(leader
);
370 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
371 update_counter_times(counter
);
375 * Cross CPU call to disable a performance counter
377 static void __perf_counter_disable(void *info
)
379 struct perf_counter
*counter
= info
;
380 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
381 struct perf_counter_context
*ctx
= counter
->ctx
;
385 * If this is a per-task counter, need to check whether this
386 * counter's task is the current task on this cpu.
388 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
391 spin_lock_irqsave(&ctx
->lock
, flags
);
394 * If the counter is on, turn it off.
395 * If it is in error state, leave it in error state.
397 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
) {
398 update_context_time(ctx
);
399 update_counter_times(counter
);
400 if (counter
== counter
->group_leader
)
401 group_sched_out(counter
, cpuctx
, ctx
);
403 counter_sched_out(counter
, cpuctx
, ctx
);
404 counter
->state
= PERF_COUNTER_STATE_OFF
;
408 spin_unlock_irqrestore(&ctx
->lock
, flags
);
414 static void perf_counter_disable(struct perf_counter
*counter
)
416 struct perf_counter_context
*ctx
= counter
->ctx
;
417 struct task_struct
*task
= ctx
->task
;
421 * Disable the counter on the cpu that it's on
423 smp_call_function_single(counter
->cpu
, __perf_counter_disable
,
429 task_oncpu_function_call(task
, __perf_counter_disable
, counter
);
431 spin_lock_irq(&ctx
->lock
);
433 * If the counter is still active, we need to retry the cross-call.
435 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
436 spin_unlock_irq(&ctx
->lock
);
441 * Since we have the lock this context can't be scheduled
442 * in, so we can change the state safely.
444 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
445 update_counter_times(counter
);
446 counter
->state
= PERF_COUNTER_STATE_OFF
;
450 spin_unlock_irq(&ctx
->lock
);
454 counter_sched_in(struct perf_counter
*counter
,
455 struct perf_cpu_context
*cpuctx
,
456 struct perf_counter_context
*ctx
,
459 if (counter
->state
<= PERF_COUNTER_STATE_OFF
)
462 counter
->state
= PERF_COUNTER_STATE_ACTIVE
;
463 counter
->oncpu
= cpu
; /* TODO: put 'cpu' into cpuctx->cpu */
465 * The new state must be visible before we turn it on in the hardware:
469 if (counter
->pmu
->enable(counter
)) {
470 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
475 counter
->tstamp_running
+= ctx
->time
- counter
->tstamp_stopped
;
477 if (!is_software_counter(counter
))
478 cpuctx
->active_oncpu
++;
481 if (counter
->hw_event
.exclusive
)
482 cpuctx
->exclusive
= 1;
488 group_sched_in(struct perf_counter
*group_counter
,
489 struct perf_cpu_context
*cpuctx
,
490 struct perf_counter_context
*ctx
,
493 struct perf_counter
*counter
, *partial_group
;
496 if (group_counter
->state
== PERF_COUNTER_STATE_OFF
)
499 ret
= hw_perf_group_sched_in(group_counter
, cpuctx
, ctx
, cpu
);
501 return ret
< 0 ? ret
: 0;
503 group_counter
->prev_state
= group_counter
->state
;
504 if (counter_sched_in(group_counter
, cpuctx
, ctx
, cpu
))
508 * Schedule in siblings as one group (if any):
510 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
511 counter
->prev_state
= counter
->state
;
512 if (counter_sched_in(counter
, cpuctx
, ctx
, cpu
)) {
513 partial_group
= counter
;
522 * Groups can be scheduled in as one unit only, so undo any
523 * partial group before returning:
525 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
526 if (counter
== partial_group
)
528 counter_sched_out(counter
, cpuctx
, ctx
);
530 counter_sched_out(group_counter
, cpuctx
, ctx
);
536 * Return 1 for a group consisting entirely of software counters,
537 * 0 if the group contains any hardware counters.
539 static int is_software_only_group(struct perf_counter
*leader
)
541 struct perf_counter
*counter
;
543 if (!is_software_counter(leader
))
546 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
547 if (!is_software_counter(counter
))
554 * Work out whether we can put this counter group on the CPU now.
556 static int group_can_go_on(struct perf_counter
*counter
,
557 struct perf_cpu_context
*cpuctx
,
561 * Groups consisting entirely of software counters can always go on.
563 if (is_software_only_group(counter
))
566 * If an exclusive group is already on, no other hardware
567 * counters can go on.
569 if (cpuctx
->exclusive
)
572 * If this group is exclusive and there are already
573 * counters on the CPU, it can't go on.
575 if (counter
->hw_event
.exclusive
&& cpuctx
->active_oncpu
)
578 * Otherwise, try to add it if all previous groups were able
584 static void add_counter_to_ctx(struct perf_counter
*counter
,
585 struct perf_counter_context
*ctx
)
587 list_add_counter(counter
, ctx
);
588 counter
->prev_state
= PERF_COUNTER_STATE_OFF
;
589 counter
->tstamp_enabled
= ctx
->time
;
590 counter
->tstamp_running
= ctx
->time
;
591 counter
->tstamp_stopped
= ctx
->time
;
595 * Cross CPU call to install and enable a performance counter
597 static void __perf_install_in_context(void *info
)
599 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
600 struct perf_counter
*counter
= info
;
601 struct perf_counter_context
*ctx
= counter
->ctx
;
602 struct perf_counter
*leader
= counter
->group_leader
;
603 int cpu
= smp_processor_id();
608 * If this is a task context, we need to check whether it is
609 * the current task context of this cpu. If not it has been
610 * scheduled out before the smp call arrived.
611 * Or possibly this is the right context but it isn't
612 * on this cpu because it had no counters.
614 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
615 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
617 cpuctx
->task_ctx
= ctx
;
620 spin_lock_irqsave(&ctx
->lock
, flags
);
622 update_context_time(ctx
);
625 * Protect the list operation against NMI by disabling the
626 * counters on a global level. NOP for non NMI based counters.
630 add_counter_to_ctx(counter
, ctx
);
633 * Don't put the counter on if it is disabled or if
634 * it is in a group and the group isn't on.
636 if (counter
->state
!= PERF_COUNTER_STATE_INACTIVE
||
637 (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
))
641 * An exclusive counter can't go on if there are already active
642 * hardware counters, and no hardware counter can go on if there
643 * is already an exclusive counter on.
645 if (!group_can_go_on(counter
, cpuctx
, 1))
648 err
= counter_sched_in(counter
, cpuctx
, ctx
, cpu
);
652 * This counter couldn't go on. If it is in a group
653 * then we have to pull the whole group off.
654 * If the counter group is pinned then put it in error state.
656 if (leader
!= counter
)
657 group_sched_out(leader
, cpuctx
, ctx
);
658 if (leader
->hw_event
.pinned
) {
659 update_group_times(leader
);
660 leader
->state
= PERF_COUNTER_STATE_ERROR
;
664 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
665 cpuctx
->max_pertask
--;
670 spin_unlock_irqrestore(&ctx
->lock
, flags
);
674 * Attach a performance counter to a context
676 * First we add the counter to the list with the hardware enable bit
677 * in counter->hw_config cleared.
679 * If the counter is attached to a task which is on a CPU we use a smp
680 * call to enable it in the task context. The task might have been
681 * scheduled away, but we check this in the smp call again.
683 * Must be called with ctx->mutex held.
686 perf_install_in_context(struct perf_counter_context
*ctx
,
687 struct perf_counter
*counter
,
690 struct task_struct
*task
= ctx
->task
;
694 * Per cpu counters are installed via an smp call and
695 * the install is always sucessful.
697 smp_call_function_single(cpu
, __perf_install_in_context
,
703 task_oncpu_function_call(task
, __perf_install_in_context
,
706 spin_lock_irq(&ctx
->lock
);
708 * we need to retry the smp call.
710 if (ctx
->is_active
&& list_empty(&counter
->list_entry
)) {
711 spin_unlock_irq(&ctx
->lock
);
716 * The lock prevents that this context is scheduled in so we
717 * can add the counter safely, if it the call above did not
720 if (list_empty(&counter
->list_entry
))
721 add_counter_to_ctx(counter
, ctx
);
722 spin_unlock_irq(&ctx
->lock
);
726 * Cross CPU call to enable a performance counter
728 static void __perf_counter_enable(void *info
)
730 struct perf_counter
*counter
= info
;
731 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
732 struct perf_counter_context
*ctx
= counter
->ctx
;
733 struct perf_counter
*leader
= counter
->group_leader
;
738 * If this is a per-task counter, need to check whether this
739 * counter's task is the current task on this cpu.
741 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
742 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
744 cpuctx
->task_ctx
= ctx
;
747 spin_lock_irqsave(&ctx
->lock
, flags
);
749 update_context_time(ctx
);
751 counter
->prev_state
= counter
->state
;
752 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
754 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
755 counter
->tstamp_enabled
= ctx
->time
- counter
->total_time_enabled
;
759 * If the counter is in a group and isn't the group leader,
760 * then don't put it on unless the group is on.
762 if (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
)
765 if (!group_can_go_on(counter
, cpuctx
, 1)) {
769 if (counter
== leader
)
770 err
= group_sched_in(counter
, cpuctx
, ctx
,
773 err
= counter_sched_in(counter
, cpuctx
, ctx
,
780 * If this counter can't go on and it's part of a
781 * group, then the whole group has to come off.
783 if (leader
!= counter
)
784 group_sched_out(leader
, cpuctx
, ctx
);
785 if (leader
->hw_event
.pinned
) {
786 update_group_times(leader
);
787 leader
->state
= PERF_COUNTER_STATE_ERROR
;
792 spin_unlock_irqrestore(&ctx
->lock
, flags
);
798 static void perf_counter_enable(struct perf_counter
*counter
)
800 struct perf_counter_context
*ctx
= counter
->ctx
;
801 struct task_struct
*task
= ctx
->task
;
805 * Enable the counter on the cpu that it's on
807 smp_call_function_single(counter
->cpu
, __perf_counter_enable
,
812 spin_lock_irq(&ctx
->lock
);
813 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
817 * If the counter is in error state, clear that first.
818 * That way, if we see the counter in error state below, we
819 * know that it has gone back into error state, as distinct
820 * from the task having been scheduled away before the
821 * cross-call arrived.
823 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
824 counter
->state
= PERF_COUNTER_STATE_OFF
;
827 spin_unlock_irq(&ctx
->lock
);
828 task_oncpu_function_call(task
, __perf_counter_enable
, counter
);
830 spin_lock_irq(&ctx
->lock
);
833 * If the context is active and the counter is still off,
834 * we need to retry the cross-call.
836 if (ctx
->is_active
&& counter
->state
== PERF_COUNTER_STATE_OFF
)
840 * Since we have the lock this context can't be scheduled
841 * in, so we can change the state safely.
843 if (counter
->state
== PERF_COUNTER_STATE_OFF
) {
844 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
845 counter
->tstamp_enabled
=
846 ctx
->time
- counter
->total_time_enabled
;
850 spin_unlock_irq(&ctx
->lock
);
853 static int perf_counter_refresh(struct perf_counter
*counter
, int refresh
)
856 * not supported on inherited counters
858 if (counter
->hw_event
.inherit
)
861 atomic_add(refresh
, &counter
->event_limit
);
862 perf_counter_enable(counter
);
867 void __perf_counter_sched_out(struct perf_counter_context
*ctx
,
868 struct perf_cpu_context
*cpuctx
)
870 struct perf_counter
*counter
;
872 spin_lock(&ctx
->lock
);
874 if (likely(!ctx
->nr_counters
))
876 update_context_time(ctx
);
879 if (ctx
->nr_active
) {
880 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
881 if (counter
!= counter
->group_leader
)
882 counter_sched_out(counter
, cpuctx
, ctx
);
884 group_sched_out(counter
, cpuctx
, ctx
);
889 spin_unlock(&ctx
->lock
);
893 * Test whether two contexts are equivalent, i.e. whether they
894 * have both been cloned from the same version of the same context
895 * and they both have the same number of enabled counters.
896 * If the number of enabled counters is the same, then the set
897 * of enabled counters should be the same, because these are both
898 * inherited contexts, therefore we can't access individual counters
899 * in them directly with an fd; we can only enable/disable all
900 * counters via prctl, or enable/disable all counters in a family
901 * via ioctl, which will have the same effect on both contexts.
903 static int context_equiv(struct perf_counter_context
*ctx1
,
904 struct perf_counter_context
*ctx2
)
906 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
907 && ctx1
->parent_gen
== ctx2
->parent_gen
908 && ctx1
->nr_enabled
== ctx2
->nr_enabled
;
912 * Called from scheduler to remove the counters of the current task,
913 * with interrupts disabled.
915 * We stop each counter and update the counter value in counter->count.
917 * This does not protect us against NMI, but disable()
918 * sets the disabled bit in the control field of counter _before_
919 * accessing the counter control register. If a NMI hits, then it will
920 * not restart the counter.
922 void perf_counter_task_sched_out(struct task_struct
*task
,
923 struct task_struct
*next
, int cpu
)
925 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
926 struct perf_counter_context
*ctx
= task
->perf_counter_ctxp
;
927 struct perf_counter_context
*next_ctx
;
928 struct pt_regs
*regs
;
930 if (likely(!ctx
|| !cpuctx
->task_ctx
))
933 update_context_time(ctx
);
935 regs
= task_pt_regs(task
);
936 perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES
, 1, 1, regs
, 0);
938 next_ctx
= next
->perf_counter_ctxp
;
939 if (next_ctx
&& context_equiv(ctx
, next_ctx
)) {
940 task
->perf_counter_ctxp
= next_ctx
;
941 next
->perf_counter_ctxp
= ctx
;
943 next_ctx
->task
= task
;
947 __perf_counter_sched_out(ctx
, cpuctx
);
949 cpuctx
->task_ctx
= NULL
;
952 static void __perf_counter_task_sched_out(struct perf_counter_context
*ctx
)
954 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
956 if (!cpuctx
->task_ctx
)
958 __perf_counter_sched_out(ctx
, cpuctx
);
959 cpuctx
->task_ctx
= NULL
;
962 static void perf_counter_cpu_sched_out(struct perf_cpu_context
*cpuctx
)
964 __perf_counter_sched_out(&cpuctx
->ctx
, cpuctx
);
968 __perf_counter_sched_in(struct perf_counter_context
*ctx
,
969 struct perf_cpu_context
*cpuctx
, int cpu
)
971 struct perf_counter
*counter
;
974 spin_lock(&ctx
->lock
);
976 if (likely(!ctx
->nr_counters
))
979 ctx
->timestamp
= perf_clock();
984 * First go through the list and put on any pinned groups
985 * in order to give them the best chance of going on.
987 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
988 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
989 !counter
->hw_event
.pinned
)
991 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
994 if (counter
!= counter
->group_leader
)
995 counter_sched_in(counter
, cpuctx
, ctx
, cpu
);
997 if (group_can_go_on(counter
, cpuctx
, 1))
998 group_sched_in(counter
, cpuctx
, ctx
, cpu
);
1002 * If this pinned group hasn't been scheduled,
1003 * put it in error state.
1005 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
1006 update_group_times(counter
);
1007 counter
->state
= PERF_COUNTER_STATE_ERROR
;
1011 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1013 * Ignore counters in OFF or ERROR state, and
1014 * ignore pinned counters since we did them already.
1016 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
1017 counter
->hw_event
.pinned
)
1021 * Listen to the 'cpu' scheduling filter constraint
1024 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
1027 if (counter
!= counter
->group_leader
) {
1028 if (counter_sched_in(counter
, cpuctx
, ctx
, cpu
))
1031 if (group_can_go_on(counter
, cpuctx
, can_add_hw
)) {
1032 if (group_sched_in(counter
, cpuctx
, ctx
, cpu
))
1039 spin_unlock(&ctx
->lock
);
1043 * Called from scheduler to add the counters of the current task
1044 * with interrupts disabled.
1046 * We restore the counter value and then enable it.
1048 * This does not protect us against NMI, but enable()
1049 * sets the enabled bit in the control field of counter _before_
1050 * accessing the counter control register. If a NMI hits, then it will
1051 * keep the counter running.
1053 void perf_counter_task_sched_in(struct task_struct
*task
, int cpu
)
1055 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1056 struct perf_counter_context
*ctx
= task
->perf_counter_ctxp
;
1060 if (cpuctx
->task_ctx
== ctx
)
1062 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
1063 cpuctx
->task_ctx
= ctx
;
1066 static void perf_counter_cpu_sched_in(struct perf_cpu_context
*cpuctx
, int cpu
)
1068 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
1070 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
1073 int perf_counter_task_disable(void)
1075 struct task_struct
*curr
= current
;
1076 struct perf_counter_context
*ctx
= curr
->perf_counter_ctxp
;
1077 struct perf_counter
*counter
;
1078 unsigned long flags
;
1080 if (!ctx
|| !ctx
->nr_counters
)
1083 local_irq_save(flags
);
1085 __perf_counter_task_sched_out(ctx
);
1087 spin_lock(&ctx
->lock
);
1090 * Disable all the counters:
1094 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1095 if (counter
->state
!= PERF_COUNTER_STATE_ERROR
) {
1096 update_group_times(counter
);
1097 counter
->state
= PERF_COUNTER_STATE_OFF
;
1103 spin_unlock_irqrestore(&ctx
->lock
, flags
);
1108 int perf_counter_task_enable(void)
1110 struct task_struct
*curr
= current
;
1111 struct perf_counter_context
*ctx
= curr
->perf_counter_ctxp
;
1112 struct perf_counter
*counter
;
1113 unsigned long flags
;
1116 if (!ctx
|| !ctx
->nr_counters
)
1119 local_irq_save(flags
);
1120 cpu
= smp_processor_id();
1122 __perf_counter_task_sched_out(ctx
);
1124 spin_lock(&ctx
->lock
);
1127 * Disable all the counters:
1131 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1132 if (counter
->state
> PERF_COUNTER_STATE_OFF
)
1134 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
1135 counter
->tstamp_enabled
=
1136 ctx
->time
- counter
->total_time_enabled
;
1137 counter
->hw_event
.disabled
= 0;
1141 spin_unlock(&ctx
->lock
);
1143 perf_counter_task_sched_in(curr
, cpu
);
1145 local_irq_restore(flags
);
1150 static void perf_log_period(struct perf_counter
*counter
, u64 period
);
1152 static void perf_adjust_freq(struct perf_counter_context
*ctx
)
1154 struct perf_counter
*counter
;
1159 spin_lock(&ctx
->lock
);
1160 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1161 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
1164 if (!counter
->hw_event
.freq
|| !counter
->hw_event
.irq_freq
)
1167 events
= HZ
* counter
->hw
.interrupts
* counter
->hw
.irq_period
;
1168 period
= div64_u64(events
, counter
->hw_event
.irq_freq
);
1170 delta
= (s64
)(1 + period
- counter
->hw
.irq_period
);
1173 irq_period
= counter
->hw
.irq_period
+ delta
;
1178 perf_log_period(counter
, irq_period
);
1180 counter
->hw
.irq_period
= irq_period
;
1181 counter
->hw
.interrupts
= 0;
1183 spin_unlock(&ctx
->lock
);
1187 * Round-robin a context's counters:
1189 static void rotate_ctx(struct perf_counter_context
*ctx
)
1191 struct perf_counter
*counter
;
1193 if (!ctx
->nr_counters
)
1196 spin_lock(&ctx
->lock
);
1198 * Rotate the first entry last (works just fine for group counters too):
1201 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1202 list_move_tail(&counter
->list_entry
, &ctx
->counter_list
);
1207 spin_unlock(&ctx
->lock
);
1210 void perf_counter_task_tick(struct task_struct
*curr
, int cpu
)
1212 struct perf_cpu_context
*cpuctx
;
1213 struct perf_counter_context
*ctx
;
1215 if (!atomic_read(&nr_counters
))
1218 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1219 ctx
= curr
->perf_counter_ctxp
;
1221 perf_adjust_freq(&cpuctx
->ctx
);
1223 perf_adjust_freq(ctx
);
1225 perf_counter_cpu_sched_out(cpuctx
);
1227 __perf_counter_task_sched_out(ctx
);
1229 rotate_ctx(&cpuctx
->ctx
);
1233 perf_counter_cpu_sched_in(cpuctx
, cpu
);
1235 perf_counter_task_sched_in(curr
, cpu
);
1239 * Cross CPU call to read the hardware counter
1241 static void __read(void *info
)
1243 struct perf_counter
*counter
= info
;
1244 struct perf_counter_context
*ctx
= counter
->ctx
;
1245 unsigned long flags
;
1247 local_irq_save(flags
);
1249 update_context_time(ctx
);
1250 counter
->pmu
->read(counter
);
1251 update_counter_times(counter
);
1252 local_irq_restore(flags
);
1255 static u64
perf_counter_read(struct perf_counter
*counter
)
1258 * If counter is enabled and currently active on a CPU, update the
1259 * value in the counter structure:
1261 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
1262 smp_call_function_single(counter
->oncpu
,
1263 __read
, counter
, 1);
1264 } else if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
1265 update_counter_times(counter
);
1268 return atomic64_read(&counter
->count
);
1272 * Initialize the perf_counter context in a task_struct:
1275 __perf_counter_init_context(struct perf_counter_context
*ctx
,
1276 struct task_struct
*task
)
1278 memset(ctx
, 0, sizeof(*ctx
));
1279 spin_lock_init(&ctx
->lock
);
1280 mutex_init(&ctx
->mutex
);
1281 INIT_LIST_HEAD(&ctx
->counter_list
);
1282 INIT_LIST_HEAD(&ctx
->event_list
);
1283 atomic_set(&ctx
->refcount
, 1);
1287 static void put_context(struct perf_counter_context
*ctx
)
1290 put_task_struct(ctx
->task
);
1293 static struct perf_counter_context
*find_get_context(pid_t pid
, int cpu
)
1295 struct perf_cpu_context
*cpuctx
;
1296 struct perf_counter_context
*ctx
;
1297 struct perf_counter_context
*tctx
;
1298 struct task_struct
*task
;
1301 * If cpu is not a wildcard then this is a percpu counter:
1304 /* Must be root to operate on a CPU counter: */
1305 if (sysctl_perf_counter_priv
&& !capable(CAP_SYS_ADMIN
))
1306 return ERR_PTR(-EACCES
);
1308 if (cpu
< 0 || cpu
> num_possible_cpus())
1309 return ERR_PTR(-EINVAL
);
1312 * We could be clever and allow to attach a counter to an
1313 * offline CPU and activate it when the CPU comes up, but
1316 if (!cpu_isset(cpu
, cpu_online_map
))
1317 return ERR_PTR(-ENODEV
);
1319 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1329 task
= find_task_by_vpid(pid
);
1331 get_task_struct(task
);
1335 return ERR_PTR(-ESRCH
);
1337 /* Reuse ptrace permission checks for now. */
1338 if (!ptrace_may_access(task
, PTRACE_MODE_READ
)) {
1339 put_task_struct(task
);
1340 return ERR_PTR(-EACCES
);
1343 ctx
= task
->perf_counter_ctxp
;
1345 ctx
= kmalloc(sizeof(struct perf_counter_context
), GFP_KERNEL
);
1347 put_task_struct(task
);
1348 return ERR_PTR(-ENOMEM
);
1350 __perf_counter_init_context(ctx
, task
);
1352 * Make sure other cpus see correct values for *ctx
1353 * once task->perf_counter_ctxp is visible to them.
1356 tctx
= cmpxchg(&task
->perf_counter_ctxp
, NULL
, ctx
);
1359 * We raced with some other task; use
1360 * the context they set.
1370 static void free_counter_rcu(struct rcu_head
*head
)
1372 struct perf_counter
*counter
;
1374 counter
= container_of(head
, struct perf_counter
, rcu_head
);
1375 put_ctx(counter
->ctx
);
1379 static void perf_pending_sync(struct perf_counter
*counter
);
1381 static void free_counter(struct perf_counter
*counter
)
1383 perf_pending_sync(counter
);
1385 atomic_dec(&nr_counters
);
1386 if (counter
->hw_event
.mmap
)
1387 atomic_dec(&nr_mmap_tracking
);
1388 if (counter
->hw_event
.munmap
)
1389 atomic_dec(&nr_munmap_tracking
);
1390 if (counter
->hw_event
.comm
)
1391 atomic_dec(&nr_comm_tracking
);
1393 if (counter
->destroy
)
1394 counter
->destroy(counter
);
1396 call_rcu(&counter
->rcu_head
, free_counter_rcu
);
1400 * Called when the last reference to the file is gone.
1402 static int perf_release(struct inode
*inode
, struct file
*file
)
1404 struct perf_counter
*counter
= file
->private_data
;
1405 struct perf_counter_context
*ctx
= counter
->ctx
;
1407 file
->private_data
= NULL
;
1409 mutex_lock(&ctx
->mutex
);
1410 mutex_lock(&counter
->mutex
);
1412 perf_counter_remove_from_context(counter
);
1414 mutex_unlock(&counter
->mutex
);
1415 mutex_unlock(&ctx
->mutex
);
1417 free_counter(counter
);
1424 * Read the performance counter - simple non blocking version for now
1427 perf_read_hw(struct perf_counter
*counter
, char __user
*buf
, size_t count
)
1433 * Return end-of-file for a read on a counter that is in
1434 * error state (i.e. because it was pinned but it couldn't be
1435 * scheduled on to the CPU at some point).
1437 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
1440 mutex_lock(&counter
->mutex
);
1441 values
[0] = perf_counter_read(counter
);
1443 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1444 values
[n
++] = counter
->total_time_enabled
+
1445 atomic64_read(&counter
->child_total_time_enabled
);
1446 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1447 values
[n
++] = counter
->total_time_running
+
1448 atomic64_read(&counter
->child_total_time_running
);
1449 mutex_unlock(&counter
->mutex
);
1451 if (count
< n
* sizeof(u64
))
1453 count
= n
* sizeof(u64
);
1455 if (copy_to_user(buf
, values
, count
))
1462 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
1464 struct perf_counter
*counter
= file
->private_data
;
1466 return perf_read_hw(counter
, buf
, count
);
1469 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
1471 struct perf_counter
*counter
= file
->private_data
;
1472 struct perf_mmap_data
*data
;
1473 unsigned int events
= POLL_HUP
;
1476 data
= rcu_dereference(counter
->data
);
1478 events
= atomic_xchg(&data
->poll
, 0);
1481 poll_wait(file
, &counter
->waitq
, wait
);
1486 static void perf_counter_reset(struct perf_counter
*counter
)
1488 (void)perf_counter_read(counter
);
1489 atomic64_set(&counter
->count
, 0);
1490 perf_counter_update_userpage(counter
);
1493 static void perf_counter_for_each_sibling(struct perf_counter
*counter
,
1494 void (*func
)(struct perf_counter
*))
1496 struct perf_counter_context
*ctx
= counter
->ctx
;
1497 struct perf_counter
*sibling
;
1499 spin_lock_irq(&ctx
->lock
);
1500 counter
= counter
->group_leader
;
1503 list_for_each_entry(sibling
, &counter
->sibling_list
, list_entry
)
1505 spin_unlock_irq(&ctx
->lock
);
1508 static void perf_counter_for_each_child(struct perf_counter
*counter
,
1509 void (*func
)(struct perf_counter
*))
1511 struct perf_counter
*child
;
1513 mutex_lock(&counter
->mutex
);
1515 list_for_each_entry(child
, &counter
->child_list
, child_list
)
1517 mutex_unlock(&counter
->mutex
);
1520 static void perf_counter_for_each(struct perf_counter
*counter
,
1521 void (*func
)(struct perf_counter
*))
1523 struct perf_counter
*child
;
1525 mutex_lock(&counter
->mutex
);
1526 perf_counter_for_each_sibling(counter
, func
);
1527 list_for_each_entry(child
, &counter
->child_list
, child_list
)
1528 perf_counter_for_each_sibling(child
, func
);
1529 mutex_unlock(&counter
->mutex
);
1532 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
1534 struct perf_counter
*counter
= file
->private_data
;
1535 void (*func
)(struct perf_counter
*);
1539 case PERF_COUNTER_IOC_ENABLE
:
1540 func
= perf_counter_enable
;
1542 case PERF_COUNTER_IOC_DISABLE
:
1543 func
= perf_counter_disable
;
1545 case PERF_COUNTER_IOC_RESET
:
1546 func
= perf_counter_reset
;
1549 case PERF_COUNTER_IOC_REFRESH
:
1550 return perf_counter_refresh(counter
, arg
);
1555 if (flags
& PERF_IOC_FLAG_GROUP
)
1556 perf_counter_for_each(counter
, func
);
1558 perf_counter_for_each_child(counter
, func
);
1564 * Callers need to ensure there can be no nesting of this function, otherwise
1565 * the seqlock logic goes bad. We can not serialize this because the arch
1566 * code calls this from NMI context.
1568 void perf_counter_update_userpage(struct perf_counter
*counter
)
1570 struct perf_mmap_data
*data
;
1571 struct perf_counter_mmap_page
*userpg
;
1574 data
= rcu_dereference(counter
->data
);
1578 userpg
= data
->user_page
;
1581 * Disable preemption so as to not let the corresponding user-space
1582 * spin too long if we get preempted.
1587 userpg
->index
= counter
->hw
.idx
;
1588 userpg
->offset
= atomic64_read(&counter
->count
);
1589 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
)
1590 userpg
->offset
-= atomic64_read(&counter
->hw
.prev_count
);
1599 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1601 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1602 struct perf_mmap_data
*data
;
1603 int ret
= VM_FAULT_SIGBUS
;
1606 data
= rcu_dereference(counter
->data
);
1610 if (vmf
->pgoff
== 0) {
1611 vmf
->page
= virt_to_page(data
->user_page
);
1613 int nr
= vmf
->pgoff
- 1;
1615 if ((unsigned)nr
> data
->nr_pages
)
1618 vmf
->page
= virt_to_page(data
->data_pages
[nr
]);
1620 get_page(vmf
->page
);
1628 static int perf_mmap_data_alloc(struct perf_counter
*counter
, int nr_pages
)
1630 struct perf_mmap_data
*data
;
1634 WARN_ON(atomic_read(&counter
->mmap_count
));
1636 size
= sizeof(struct perf_mmap_data
);
1637 size
+= nr_pages
* sizeof(void *);
1639 data
= kzalloc(size
, GFP_KERNEL
);
1643 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
1644 if (!data
->user_page
)
1645 goto fail_user_page
;
1647 for (i
= 0; i
< nr_pages
; i
++) {
1648 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
1649 if (!data
->data_pages
[i
])
1650 goto fail_data_pages
;
1653 data
->nr_pages
= nr_pages
;
1654 atomic_set(&data
->lock
, -1);
1656 rcu_assign_pointer(counter
->data
, data
);
1661 for (i
--; i
>= 0; i
--)
1662 free_page((unsigned long)data
->data_pages
[i
]);
1664 free_page((unsigned long)data
->user_page
);
1673 static void __perf_mmap_data_free(struct rcu_head
*rcu_head
)
1675 struct perf_mmap_data
*data
= container_of(rcu_head
,
1676 struct perf_mmap_data
, rcu_head
);
1679 free_page((unsigned long)data
->user_page
);
1680 for (i
= 0; i
< data
->nr_pages
; i
++)
1681 free_page((unsigned long)data
->data_pages
[i
]);
1685 static void perf_mmap_data_free(struct perf_counter
*counter
)
1687 struct perf_mmap_data
*data
= counter
->data
;
1689 WARN_ON(atomic_read(&counter
->mmap_count
));
1691 rcu_assign_pointer(counter
->data
, NULL
);
1692 call_rcu(&data
->rcu_head
, __perf_mmap_data_free
);
1695 static void perf_mmap_open(struct vm_area_struct
*vma
)
1697 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1699 atomic_inc(&counter
->mmap_count
);
1702 static void perf_mmap_close(struct vm_area_struct
*vma
)
1704 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1706 if (atomic_dec_and_mutex_lock(&counter
->mmap_count
,
1707 &counter
->mmap_mutex
)) {
1708 struct user_struct
*user
= current_user();
1710 atomic_long_sub(counter
->data
->nr_pages
+ 1, &user
->locked_vm
);
1711 vma
->vm_mm
->locked_vm
-= counter
->data
->nr_locked
;
1712 perf_mmap_data_free(counter
);
1713 mutex_unlock(&counter
->mmap_mutex
);
1717 static struct vm_operations_struct perf_mmap_vmops
= {
1718 .open
= perf_mmap_open
,
1719 .close
= perf_mmap_close
,
1720 .fault
= perf_mmap_fault
,
1723 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1725 struct perf_counter
*counter
= file
->private_data
;
1726 struct user_struct
*user
= current_user();
1727 unsigned long vma_size
;
1728 unsigned long nr_pages
;
1729 unsigned long user_locked
, user_lock_limit
;
1730 unsigned long locked
, lock_limit
;
1731 long user_extra
, extra
;
1734 if (!(vma
->vm_flags
& VM_SHARED
) || (vma
->vm_flags
& VM_WRITE
))
1737 vma_size
= vma
->vm_end
- vma
->vm_start
;
1738 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
1741 * If we have data pages ensure they're a power-of-two number, so we
1742 * can do bitmasks instead of modulo.
1744 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
1747 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
1750 if (vma
->vm_pgoff
!= 0)
1753 mutex_lock(&counter
->mmap_mutex
);
1754 if (atomic_inc_not_zero(&counter
->mmap_count
)) {
1755 if (nr_pages
!= counter
->data
->nr_pages
)
1760 user_extra
= nr_pages
+ 1;
1761 user_lock_limit
= sysctl_perf_counter_mlock
>> (PAGE_SHIFT
- 10);
1762 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
1765 if (user_locked
> user_lock_limit
)
1766 extra
= user_locked
- user_lock_limit
;
1768 lock_limit
= current
->signal
->rlim
[RLIMIT_MEMLOCK
].rlim_cur
;
1769 lock_limit
>>= PAGE_SHIFT
;
1770 locked
= vma
->vm_mm
->locked_vm
+ extra
;
1772 if ((locked
> lock_limit
) && !capable(CAP_IPC_LOCK
)) {
1777 WARN_ON(counter
->data
);
1778 ret
= perf_mmap_data_alloc(counter
, nr_pages
);
1782 atomic_set(&counter
->mmap_count
, 1);
1783 atomic_long_add(user_extra
, &user
->locked_vm
);
1784 vma
->vm_mm
->locked_vm
+= extra
;
1785 counter
->data
->nr_locked
= extra
;
1787 mutex_unlock(&counter
->mmap_mutex
);
1789 vma
->vm_flags
&= ~VM_MAYWRITE
;
1790 vma
->vm_flags
|= VM_RESERVED
;
1791 vma
->vm_ops
= &perf_mmap_vmops
;
1796 static int perf_fasync(int fd
, struct file
*filp
, int on
)
1798 struct perf_counter
*counter
= filp
->private_data
;
1799 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
1802 mutex_lock(&inode
->i_mutex
);
1803 retval
= fasync_helper(fd
, filp
, on
, &counter
->fasync
);
1804 mutex_unlock(&inode
->i_mutex
);
1812 static const struct file_operations perf_fops
= {
1813 .release
= perf_release
,
1816 .unlocked_ioctl
= perf_ioctl
,
1817 .compat_ioctl
= perf_ioctl
,
1819 .fasync
= perf_fasync
,
1823 * Perf counter wakeup
1825 * If there's data, ensure we set the poll() state and publish everything
1826 * to user-space before waking everybody up.
1829 void perf_counter_wakeup(struct perf_counter
*counter
)
1831 wake_up_all(&counter
->waitq
);
1833 if (counter
->pending_kill
) {
1834 kill_fasync(&counter
->fasync
, SIGIO
, counter
->pending_kill
);
1835 counter
->pending_kill
= 0;
1842 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
1844 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
1845 * single linked list and use cmpxchg() to add entries lockless.
1848 static void perf_pending_counter(struct perf_pending_entry
*entry
)
1850 struct perf_counter
*counter
= container_of(entry
,
1851 struct perf_counter
, pending
);
1853 if (counter
->pending_disable
) {
1854 counter
->pending_disable
= 0;
1855 perf_counter_disable(counter
);
1858 if (counter
->pending_wakeup
) {
1859 counter
->pending_wakeup
= 0;
1860 perf_counter_wakeup(counter
);
1864 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
1866 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
1870 static void perf_pending_queue(struct perf_pending_entry
*entry
,
1871 void (*func
)(struct perf_pending_entry
*))
1873 struct perf_pending_entry
**head
;
1875 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
1880 head
= &get_cpu_var(perf_pending_head
);
1883 entry
->next
= *head
;
1884 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
1886 set_perf_counter_pending();
1888 put_cpu_var(perf_pending_head
);
1891 static int __perf_pending_run(void)
1893 struct perf_pending_entry
*list
;
1896 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
1897 while (list
!= PENDING_TAIL
) {
1898 void (*func
)(struct perf_pending_entry
*);
1899 struct perf_pending_entry
*entry
= list
;
1906 * Ensure we observe the unqueue before we issue the wakeup,
1907 * so that we won't be waiting forever.
1908 * -- see perf_not_pending().
1919 static inline int perf_not_pending(struct perf_counter
*counter
)
1922 * If we flush on whatever cpu we run, there is a chance we don't
1926 __perf_pending_run();
1930 * Ensure we see the proper queue state before going to sleep
1931 * so that we do not miss the wakeup. -- see perf_pending_handle()
1934 return counter
->pending
.next
== NULL
;
1937 static void perf_pending_sync(struct perf_counter
*counter
)
1939 wait_event(counter
->waitq
, perf_not_pending(counter
));
1942 void perf_counter_do_pending(void)
1944 __perf_pending_run();
1948 * Callchain support -- arch specific
1951 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
1960 struct perf_output_handle
{
1961 struct perf_counter
*counter
;
1962 struct perf_mmap_data
*data
;
1963 unsigned int offset
;
1968 unsigned long flags
;
1971 static void perf_output_wakeup(struct perf_output_handle
*handle
)
1973 atomic_set(&handle
->data
->poll
, POLL_IN
);
1976 handle
->counter
->pending_wakeup
= 1;
1977 perf_pending_queue(&handle
->counter
->pending
,
1978 perf_pending_counter
);
1980 perf_counter_wakeup(handle
->counter
);
1984 * Curious locking construct.
1986 * We need to ensure a later event doesn't publish a head when a former
1987 * event isn't done writing. However since we need to deal with NMIs we
1988 * cannot fully serialize things.
1990 * What we do is serialize between CPUs so we only have to deal with NMI
1991 * nesting on a single CPU.
1993 * We only publish the head (and generate a wakeup) when the outer-most
1996 static void perf_output_lock(struct perf_output_handle
*handle
)
1998 struct perf_mmap_data
*data
= handle
->data
;
2003 local_irq_save(handle
->flags
);
2004 cpu
= smp_processor_id();
2006 if (in_nmi() && atomic_read(&data
->lock
) == cpu
)
2009 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2015 static void perf_output_unlock(struct perf_output_handle
*handle
)
2017 struct perf_mmap_data
*data
= handle
->data
;
2020 data
->done_head
= data
->head
;
2022 if (!handle
->locked
)
2027 * The xchg implies a full barrier that ensures all writes are done
2028 * before we publish the new head, matched by a rmb() in userspace when
2029 * reading this position.
2031 while ((head
= atomic_xchg(&data
->done_head
, 0)))
2032 data
->user_page
->data_head
= head
;
2035 * NMI can happen here, which means we can miss a done_head update.
2038 cpu
= atomic_xchg(&data
->lock
, -1);
2039 WARN_ON_ONCE(cpu
!= smp_processor_id());
2042 * Therefore we have to validate we did not indeed do so.
2044 if (unlikely(atomic_read(&data
->done_head
))) {
2046 * Since we had it locked, we can lock it again.
2048 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2054 if (atomic_xchg(&data
->wakeup
, 0))
2055 perf_output_wakeup(handle
);
2057 local_irq_restore(handle
->flags
);
2060 static int perf_output_begin(struct perf_output_handle
*handle
,
2061 struct perf_counter
*counter
, unsigned int size
,
2062 int nmi
, int overflow
)
2064 struct perf_mmap_data
*data
;
2065 unsigned int offset
, head
;
2068 * For inherited counters we send all the output towards the parent.
2070 if (counter
->parent
)
2071 counter
= counter
->parent
;
2074 data
= rcu_dereference(counter
->data
);
2078 handle
->data
= data
;
2079 handle
->counter
= counter
;
2081 handle
->overflow
= overflow
;
2083 if (!data
->nr_pages
)
2086 perf_output_lock(handle
);
2089 offset
= head
= atomic_read(&data
->head
);
2091 } while (atomic_cmpxchg(&data
->head
, offset
, head
) != offset
);
2093 handle
->offset
= offset
;
2094 handle
->head
= head
;
2096 if ((offset
>> PAGE_SHIFT
) != (head
>> PAGE_SHIFT
))
2097 atomic_set(&data
->wakeup
, 1);
2102 perf_output_wakeup(handle
);
2109 static void perf_output_copy(struct perf_output_handle
*handle
,
2110 void *buf
, unsigned int len
)
2112 unsigned int pages_mask
;
2113 unsigned int offset
;
2117 offset
= handle
->offset
;
2118 pages_mask
= handle
->data
->nr_pages
- 1;
2119 pages
= handle
->data
->data_pages
;
2122 unsigned int page_offset
;
2125 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2126 page_offset
= offset
& (PAGE_SIZE
- 1);
2127 size
= min_t(unsigned int, PAGE_SIZE
- page_offset
, len
);
2129 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2136 handle
->offset
= offset
;
2139 * Check we didn't copy past our reservation window, taking the
2140 * possible unsigned int wrap into account.
2142 WARN_ON_ONCE(((int)(handle
->head
- handle
->offset
)) < 0);
2145 #define perf_output_put(handle, x) \
2146 perf_output_copy((handle), &(x), sizeof(x))
2148 static void perf_output_end(struct perf_output_handle
*handle
)
2150 struct perf_counter
*counter
= handle
->counter
;
2151 struct perf_mmap_data
*data
= handle
->data
;
2153 int wakeup_events
= counter
->hw_event
.wakeup_events
;
2155 if (handle
->overflow
&& wakeup_events
) {
2156 int events
= atomic_inc_return(&data
->events
);
2157 if (events
>= wakeup_events
) {
2158 atomic_sub(wakeup_events
, &data
->events
);
2159 atomic_set(&data
->wakeup
, 1);
2163 perf_output_unlock(handle
);
2167 static void perf_counter_output(struct perf_counter
*counter
,
2168 int nmi
, struct pt_regs
*regs
, u64 addr
)
2171 u64 record_type
= counter
->hw_event
.record_type
;
2172 struct perf_output_handle handle
;
2173 struct perf_event_header header
;
2182 struct perf_callchain_entry
*callchain
= NULL
;
2183 int callchain_size
= 0;
2190 header
.size
= sizeof(header
);
2192 header
.misc
= PERF_EVENT_MISC_OVERFLOW
;
2193 header
.misc
|= perf_misc_flags(regs
);
2195 if (record_type
& PERF_RECORD_IP
) {
2196 ip
= perf_instruction_pointer(regs
);
2197 header
.type
|= PERF_RECORD_IP
;
2198 header
.size
+= sizeof(ip
);
2201 if (record_type
& PERF_RECORD_TID
) {
2202 /* namespace issues */
2203 tid_entry
.pid
= current
->group_leader
->pid
;
2204 tid_entry
.tid
= current
->pid
;
2206 header
.type
|= PERF_RECORD_TID
;
2207 header
.size
+= sizeof(tid_entry
);
2210 if (record_type
& PERF_RECORD_TIME
) {
2212 * Maybe do better on x86 and provide cpu_clock_nmi()
2214 time
= sched_clock();
2216 header
.type
|= PERF_RECORD_TIME
;
2217 header
.size
+= sizeof(u64
);
2220 if (record_type
& PERF_RECORD_ADDR
) {
2221 header
.type
|= PERF_RECORD_ADDR
;
2222 header
.size
+= sizeof(u64
);
2225 if (record_type
& PERF_RECORD_CONFIG
) {
2226 header
.type
|= PERF_RECORD_CONFIG
;
2227 header
.size
+= sizeof(u64
);
2230 if (record_type
& PERF_RECORD_CPU
) {
2231 header
.type
|= PERF_RECORD_CPU
;
2232 header
.size
+= sizeof(cpu_entry
);
2234 cpu_entry
.cpu
= raw_smp_processor_id();
2237 if (record_type
& PERF_RECORD_GROUP
) {
2238 header
.type
|= PERF_RECORD_GROUP
;
2239 header
.size
+= sizeof(u64
) +
2240 counter
->nr_siblings
* sizeof(group_entry
);
2243 if (record_type
& PERF_RECORD_CALLCHAIN
) {
2244 callchain
= perf_callchain(regs
);
2247 callchain_size
= (1 + callchain
->nr
) * sizeof(u64
);
2249 header
.type
|= PERF_RECORD_CALLCHAIN
;
2250 header
.size
+= callchain_size
;
2254 ret
= perf_output_begin(&handle
, counter
, header
.size
, nmi
, 1);
2258 perf_output_put(&handle
, header
);
2260 if (record_type
& PERF_RECORD_IP
)
2261 perf_output_put(&handle
, ip
);
2263 if (record_type
& PERF_RECORD_TID
)
2264 perf_output_put(&handle
, tid_entry
);
2266 if (record_type
& PERF_RECORD_TIME
)
2267 perf_output_put(&handle
, time
);
2269 if (record_type
& PERF_RECORD_ADDR
)
2270 perf_output_put(&handle
, addr
);
2272 if (record_type
& PERF_RECORD_CONFIG
)
2273 perf_output_put(&handle
, counter
->hw_event
.config
);
2275 if (record_type
& PERF_RECORD_CPU
)
2276 perf_output_put(&handle
, cpu_entry
);
2279 * XXX PERF_RECORD_GROUP vs inherited counters seems difficult.
2281 if (record_type
& PERF_RECORD_GROUP
) {
2282 struct perf_counter
*leader
, *sub
;
2283 u64 nr
= counter
->nr_siblings
;
2285 perf_output_put(&handle
, nr
);
2287 leader
= counter
->group_leader
;
2288 list_for_each_entry(sub
, &leader
->sibling_list
, list_entry
) {
2290 sub
->pmu
->read(sub
);
2292 group_entry
.event
= sub
->hw_event
.config
;
2293 group_entry
.counter
= atomic64_read(&sub
->count
);
2295 perf_output_put(&handle
, group_entry
);
2300 perf_output_copy(&handle
, callchain
, callchain_size
);
2302 perf_output_end(&handle
);
2309 struct perf_comm_event
{
2310 struct task_struct
*task
;
2315 struct perf_event_header header
;
2322 static void perf_counter_comm_output(struct perf_counter
*counter
,
2323 struct perf_comm_event
*comm_event
)
2325 struct perf_output_handle handle
;
2326 int size
= comm_event
->event
.header
.size
;
2327 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
2332 perf_output_put(&handle
, comm_event
->event
);
2333 perf_output_copy(&handle
, comm_event
->comm
,
2334 comm_event
->comm_size
);
2335 perf_output_end(&handle
);
2338 static int perf_counter_comm_match(struct perf_counter
*counter
,
2339 struct perf_comm_event
*comm_event
)
2341 if (counter
->hw_event
.comm
&&
2342 comm_event
->event
.header
.type
== PERF_EVENT_COMM
)
2348 static void perf_counter_comm_ctx(struct perf_counter_context
*ctx
,
2349 struct perf_comm_event
*comm_event
)
2351 struct perf_counter
*counter
;
2353 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2357 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2358 if (perf_counter_comm_match(counter
, comm_event
))
2359 perf_counter_comm_output(counter
, comm_event
);
2364 static void perf_counter_comm_event(struct perf_comm_event
*comm_event
)
2366 struct perf_cpu_context
*cpuctx
;
2368 char *comm
= comm_event
->task
->comm
;
2370 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
2372 comm_event
->comm
= comm
;
2373 comm_event
->comm_size
= size
;
2375 comm_event
->event
.header
.size
= sizeof(comm_event
->event
) + size
;
2377 cpuctx
= &get_cpu_var(perf_cpu_context
);
2378 perf_counter_comm_ctx(&cpuctx
->ctx
, comm_event
);
2379 put_cpu_var(perf_cpu_context
);
2381 perf_counter_comm_ctx(current
->perf_counter_ctxp
, comm_event
);
2384 void perf_counter_comm(struct task_struct
*task
)
2386 struct perf_comm_event comm_event
;
2388 if (!atomic_read(&nr_comm_tracking
))
2390 if (!current
->perf_counter_ctxp
)
2393 comm_event
= (struct perf_comm_event
){
2396 .header
= { .type
= PERF_EVENT_COMM
, },
2397 .pid
= task
->group_leader
->pid
,
2402 perf_counter_comm_event(&comm_event
);
2409 struct perf_mmap_event
{
2415 struct perf_event_header header
;
2425 static void perf_counter_mmap_output(struct perf_counter
*counter
,
2426 struct perf_mmap_event
*mmap_event
)
2428 struct perf_output_handle handle
;
2429 int size
= mmap_event
->event
.header
.size
;
2430 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
2435 perf_output_put(&handle
, mmap_event
->event
);
2436 perf_output_copy(&handle
, mmap_event
->file_name
,
2437 mmap_event
->file_size
);
2438 perf_output_end(&handle
);
2441 static int perf_counter_mmap_match(struct perf_counter
*counter
,
2442 struct perf_mmap_event
*mmap_event
)
2444 if (counter
->hw_event
.mmap
&&
2445 mmap_event
->event
.header
.type
== PERF_EVENT_MMAP
)
2448 if (counter
->hw_event
.munmap
&&
2449 mmap_event
->event
.header
.type
== PERF_EVENT_MUNMAP
)
2455 static void perf_counter_mmap_ctx(struct perf_counter_context
*ctx
,
2456 struct perf_mmap_event
*mmap_event
)
2458 struct perf_counter
*counter
;
2460 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2464 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2465 if (perf_counter_mmap_match(counter
, mmap_event
))
2466 perf_counter_mmap_output(counter
, mmap_event
);
2471 static void perf_counter_mmap_event(struct perf_mmap_event
*mmap_event
)
2473 struct perf_cpu_context
*cpuctx
;
2474 struct file
*file
= mmap_event
->file
;
2481 buf
= kzalloc(PATH_MAX
, GFP_KERNEL
);
2483 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
2486 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
2488 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
2492 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
2497 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
2499 mmap_event
->file_name
= name
;
2500 mmap_event
->file_size
= size
;
2502 mmap_event
->event
.header
.size
= sizeof(mmap_event
->event
) + size
;
2504 cpuctx
= &get_cpu_var(perf_cpu_context
);
2505 perf_counter_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
2506 put_cpu_var(perf_cpu_context
);
2508 perf_counter_mmap_ctx(current
->perf_counter_ctxp
, mmap_event
);
2513 void perf_counter_mmap(unsigned long addr
, unsigned long len
,
2514 unsigned long pgoff
, struct file
*file
)
2516 struct perf_mmap_event mmap_event
;
2518 if (!atomic_read(&nr_mmap_tracking
))
2520 if (!current
->perf_counter_ctxp
)
2523 mmap_event
= (struct perf_mmap_event
){
2526 .header
= { .type
= PERF_EVENT_MMAP
, },
2527 .pid
= current
->group_leader
->pid
,
2528 .tid
= current
->pid
,
2535 perf_counter_mmap_event(&mmap_event
);
2538 void perf_counter_munmap(unsigned long addr
, unsigned long len
,
2539 unsigned long pgoff
, struct file
*file
)
2541 struct perf_mmap_event mmap_event
;
2543 if (!atomic_read(&nr_munmap_tracking
))
2546 mmap_event
= (struct perf_mmap_event
){
2549 .header
= { .type
= PERF_EVENT_MUNMAP
, },
2550 .pid
= current
->group_leader
->pid
,
2551 .tid
= current
->pid
,
2558 perf_counter_mmap_event(&mmap_event
);
2562 * Log irq_period changes so that analyzing tools can re-normalize the
2566 static void perf_log_period(struct perf_counter
*counter
, u64 period
)
2568 struct perf_output_handle handle
;
2572 struct perf_event_header header
;
2577 .type
= PERF_EVENT_PERIOD
,
2579 .size
= sizeof(freq_event
),
2581 .time
= sched_clock(),
2585 if (counter
->hw
.irq_period
== period
)
2588 ret
= perf_output_begin(&handle
, counter
, sizeof(freq_event
), 0, 0);
2592 perf_output_put(&handle
, freq_event
);
2593 perf_output_end(&handle
);
2597 * Generic counter overflow handling.
2600 int perf_counter_overflow(struct perf_counter
*counter
,
2601 int nmi
, struct pt_regs
*regs
, u64 addr
)
2603 int events
= atomic_read(&counter
->event_limit
);
2606 counter
->hw
.interrupts
++;
2609 * XXX event_limit might not quite work as expected on inherited
2613 counter
->pending_kill
= POLL_IN
;
2614 if (events
&& atomic_dec_and_test(&counter
->event_limit
)) {
2616 counter
->pending_kill
= POLL_HUP
;
2618 counter
->pending_disable
= 1;
2619 perf_pending_queue(&counter
->pending
,
2620 perf_pending_counter
);
2622 perf_counter_disable(counter
);
2625 perf_counter_output(counter
, nmi
, regs
, addr
);
2630 * Generic software counter infrastructure
2633 static void perf_swcounter_update(struct perf_counter
*counter
)
2635 struct hw_perf_counter
*hwc
= &counter
->hw
;
2640 prev
= atomic64_read(&hwc
->prev_count
);
2641 now
= atomic64_read(&hwc
->count
);
2642 if (atomic64_cmpxchg(&hwc
->prev_count
, prev
, now
) != prev
)
2647 atomic64_add(delta
, &counter
->count
);
2648 atomic64_sub(delta
, &hwc
->period_left
);
2651 static void perf_swcounter_set_period(struct perf_counter
*counter
)
2653 struct hw_perf_counter
*hwc
= &counter
->hw
;
2654 s64 left
= atomic64_read(&hwc
->period_left
);
2655 s64 period
= hwc
->irq_period
;
2657 if (unlikely(left
<= -period
)) {
2659 atomic64_set(&hwc
->period_left
, left
);
2662 if (unlikely(left
<= 0)) {
2664 atomic64_add(period
, &hwc
->period_left
);
2667 atomic64_set(&hwc
->prev_count
, -left
);
2668 atomic64_set(&hwc
->count
, -left
);
2671 static enum hrtimer_restart
perf_swcounter_hrtimer(struct hrtimer
*hrtimer
)
2673 enum hrtimer_restart ret
= HRTIMER_RESTART
;
2674 struct perf_counter
*counter
;
2675 struct pt_regs
*regs
;
2678 counter
= container_of(hrtimer
, struct perf_counter
, hw
.hrtimer
);
2679 counter
->pmu
->read(counter
);
2681 regs
= get_irq_regs();
2683 * In case we exclude kernel IPs or are somehow not in interrupt
2684 * context, provide the next best thing, the user IP.
2686 if ((counter
->hw_event
.exclude_kernel
|| !regs
) &&
2687 !counter
->hw_event
.exclude_user
)
2688 regs
= task_pt_regs(current
);
2691 if (perf_counter_overflow(counter
, 0, regs
, 0))
2692 ret
= HRTIMER_NORESTART
;
2695 period
= max_t(u64
, 10000, counter
->hw
.irq_period
);
2696 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
2701 static void perf_swcounter_overflow(struct perf_counter
*counter
,
2702 int nmi
, struct pt_regs
*regs
, u64 addr
)
2704 perf_swcounter_update(counter
);
2705 perf_swcounter_set_period(counter
);
2706 if (perf_counter_overflow(counter
, nmi
, regs
, addr
))
2707 /* soft-disable the counter */
2712 static int perf_swcounter_match(struct perf_counter
*counter
,
2713 enum perf_event_types type
,
2714 u32 event
, struct pt_regs
*regs
)
2716 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
2719 if (perf_event_raw(&counter
->hw_event
))
2722 if (perf_event_type(&counter
->hw_event
) != type
)
2725 if (perf_event_id(&counter
->hw_event
) != event
)
2728 if (counter
->hw_event
.exclude_user
&& user_mode(regs
))
2731 if (counter
->hw_event
.exclude_kernel
&& !user_mode(regs
))
2737 static void perf_swcounter_add(struct perf_counter
*counter
, u64 nr
,
2738 int nmi
, struct pt_regs
*regs
, u64 addr
)
2740 int neg
= atomic64_add_negative(nr
, &counter
->hw
.count
);
2741 if (counter
->hw
.irq_period
&& !neg
)
2742 perf_swcounter_overflow(counter
, nmi
, regs
, addr
);
2745 static void perf_swcounter_ctx_event(struct perf_counter_context
*ctx
,
2746 enum perf_event_types type
, u32 event
,
2747 u64 nr
, int nmi
, struct pt_regs
*regs
,
2750 struct perf_counter
*counter
;
2752 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2756 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2757 if (perf_swcounter_match(counter
, type
, event
, regs
))
2758 perf_swcounter_add(counter
, nr
, nmi
, regs
, addr
);
2763 static int *perf_swcounter_recursion_context(struct perf_cpu_context
*cpuctx
)
2766 return &cpuctx
->recursion
[3];
2769 return &cpuctx
->recursion
[2];
2772 return &cpuctx
->recursion
[1];
2774 return &cpuctx
->recursion
[0];
2777 static void __perf_swcounter_event(enum perf_event_types type
, u32 event
,
2778 u64 nr
, int nmi
, struct pt_regs
*regs
,
2781 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
2782 int *recursion
= perf_swcounter_recursion_context(cpuctx
);
2790 perf_swcounter_ctx_event(&cpuctx
->ctx
, type
, event
,
2791 nr
, nmi
, regs
, addr
);
2792 if (cpuctx
->task_ctx
) {
2793 perf_swcounter_ctx_event(cpuctx
->task_ctx
, type
, event
,
2794 nr
, nmi
, regs
, addr
);
2801 put_cpu_var(perf_cpu_context
);
2805 perf_swcounter_event(u32 event
, u64 nr
, int nmi
, struct pt_regs
*regs
, u64 addr
)
2807 __perf_swcounter_event(PERF_TYPE_SOFTWARE
, event
, nr
, nmi
, regs
, addr
);
2810 static void perf_swcounter_read(struct perf_counter
*counter
)
2812 perf_swcounter_update(counter
);
2815 static int perf_swcounter_enable(struct perf_counter
*counter
)
2817 perf_swcounter_set_period(counter
);
2821 static void perf_swcounter_disable(struct perf_counter
*counter
)
2823 perf_swcounter_update(counter
);
2826 static const struct pmu perf_ops_generic
= {
2827 .enable
= perf_swcounter_enable
,
2828 .disable
= perf_swcounter_disable
,
2829 .read
= perf_swcounter_read
,
2833 * Software counter: cpu wall time clock
2836 static void cpu_clock_perf_counter_update(struct perf_counter
*counter
)
2838 int cpu
= raw_smp_processor_id();
2842 now
= cpu_clock(cpu
);
2843 prev
= atomic64_read(&counter
->hw
.prev_count
);
2844 atomic64_set(&counter
->hw
.prev_count
, now
);
2845 atomic64_add(now
- prev
, &counter
->count
);
2848 static int cpu_clock_perf_counter_enable(struct perf_counter
*counter
)
2850 struct hw_perf_counter
*hwc
= &counter
->hw
;
2851 int cpu
= raw_smp_processor_id();
2853 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
2854 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2855 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2856 if (hwc
->irq_period
) {
2857 u64 period
= max_t(u64
, 10000, hwc
->irq_period
);
2858 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2859 ns_to_ktime(period
), 0,
2860 HRTIMER_MODE_REL
, 0);
2866 static void cpu_clock_perf_counter_disable(struct perf_counter
*counter
)
2868 if (counter
->hw
.irq_period
)
2869 hrtimer_cancel(&counter
->hw
.hrtimer
);
2870 cpu_clock_perf_counter_update(counter
);
2873 static void cpu_clock_perf_counter_read(struct perf_counter
*counter
)
2875 cpu_clock_perf_counter_update(counter
);
2878 static const struct pmu perf_ops_cpu_clock
= {
2879 .enable
= cpu_clock_perf_counter_enable
,
2880 .disable
= cpu_clock_perf_counter_disable
,
2881 .read
= cpu_clock_perf_counter_read
,
2885 * Software counter: task time clock
2888 static void task_clock_perf_counter_update(struct perf_counter
*counter
, u64 now
)
2893 prev
= atomic64_xchg(&counter
->hw
.prev_count
, now
);
2895 atomic64_add(delta
, &counter
->count
);
2898 static int task_clock_perf_counter_enable(struct perf_counter
*counter
)
2900 struct hw_perf_counter
*hwc
= &counter
->hw
;
2903 now
= counter
->ctx
->time
;
2905 atomic64_set(&hwc
->prev_count
, now
);
2906 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2907 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2908 if (hwc
->irq_period
) {
2909 u64 period
= max_t(u64
, 10000, hwc
->irq_period
);
2910 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2911 ns_to_ktime(period
), 0,
2912 HRTIMER_MODE_REL
, 0);
2918 static void task_clock_perf_counter_disable(struct perf_counter
*counter
)
2920 if (counter
->hw
.irq_period
)
2921 hrtimer_cancel(&counter
->hw
.hrtimer
);
2922 task_clock_perf_counter_update(counter
, counter
->ctx
->time
);
2926 static void task_clock_perf_counter_read(struct perf_counter
*counter
)
2931 update_context_time(counter
->ctx
);
2932 time
= counter
->ctx
->time
;
2934 u64 now
= perf_clock();
2935 u64 delta
= now
- counter
->ctx
->timestamp
;
2936 time
= counter
->ctx
->time
+ delta
;
2939 task_clock_perf_counter_update(counter
, time
);
2942 static const struct pmu perf_ops_task_clock
= {
2943 .enable
= task_clock_perf_counter_enable
,
2944 .disable
= task_clock_perf_counter_disable
,
2945 .read
= task_clock_perf_counter_read
,
2949 * Software counter: cpu migrations
2952 static inline u64
get_cpu_migrations(struct perf_counter
*counter
)
2954 struct task_struct
*curr
= counter
->ctx
->task
;
2957 return curr
->se
.nr_migrations
;
2958 return cpu_nr_migrations(smp_processor_id());
2961 static void cpu_migrations_perf_counter_update(struct perf_counter
*counter
)
2966 prev
= atomic64_read(&counter
->hw
.prev_count
);
2967 now
= get_cpu_migrations(counter
);
2969 atomic64_set(&counter
->hw
.prev_count
, now
);
2973 atomic64_add(delta
, &counter
->count
);
2976 static void cpu_migrations_perf_counter_read(struct perf_counter
*counter
)
2978 cpu_migrations_perf_counter_update(counter
);
2981 static int cpu_migrations_perf_counter_enable(struct perf_counter
*counter
)
2983 if (counter
->prev_state
<= PERF_COUNTER_STATE_OFF
)
2984 atomic64_set(&counter
->hw
.prev_count
,
2985 get_cpu_migrations(counter
));
2989 static void cpu_migrations_perf_counter_disable(struct perf_counter
*counter
)
2991 cpu_migrations_perf_counter_update(counter
);
2994 static const struct pmu perf_ops_cpu_migrations
= {
2995 .enable
= cpu_migrations_perf_counter_enable
,
2996 .disable
= cpu_migrations_perf_counter_disable
,
2997 .read
= cpu_migrations_perf_counter_read
,
3000 #ifdef CONFIG_EVENT_PROFILE
3001 void perf_tpcounter_event(int event_id
)
3003 struct pt_regs
*regs
= get_irq_regs();
3006 regs
= task_pt_regs(current
);
3008 __perf_swcounter_event(PERF_TYPE_TRACEPOINT
, event_id
, 1, 1, regs
, 0);
3010 EXPORT_SYMBOL_GPL(perf_tpcounter_event
);
3012 extern int ftrace_profile_enable(int);
3013 extern void ftrace_profile_disable(int);
3015 static void tp_perf_counter_destroy(struct perf_counter
*counter
)
3017 ftrace_profile_disable(perf_event_id(&counter
->hw_event
));
3020 static const struct pmu
*tp_perf_counter_init(struct perf_counter
*counter
)
3022 int event_id
= perf_event_id(&counter
->hw_event
);
3025 ret
= ftrace_profile_enable(event_id
);
3029 counter
->destroy
= tp_perf_counter_destroy
;
3030 counter
->hw
.irq_period
= counter
->hw_event
.irq_period
;
3032 return &perf_ops_generic
;
3035 static const struct pmu
*tp_perf_counter_init(struct perf_counter
*counter
)
3041 static const struct pmu
*sw_perf_counter_init(struct perf_counter
*counter
)
3043 const struct pmu
*pmu
= NULL
;
3046 * Software counters (currently) can't in general distinguish
3047 * between user, kernel and hypervisor events.
3048 * However, context switches and cpu migrations are considered
3049 * to be kernel events, and page faults are never hypervisor
3052 switch (perf_event_id(&counter
->hw_event
)) {
3053 case PERF_COUNT_CPU_CLOCK
:
3054 pmu
= &perf_ops_cpu_clock
;
3057 case PERF_COUNT_TASK_CLOCK
:
3059 * If the user instantiates this as a per-cpu counter,
3060 * use the cpu_clock counter instead.
3062 if (counter
->ctx
->task
)
3063 pmu
= &perf_ops_task_clock
;
3065 pmu
= &perf_ops_cpu_clock
;
3068 case PERF_COUNT_PAGE_FAULTS
:
3069 case PERF_COUNT_PAGE_FAULTS_MIN
:
3070 case PERF_COUNT_PAGE_FAULTS_MAJ
:
3071 case PERF_COUNT_CONTEXT_SWITCHES
:
3072 pmu
= &perf_ops_generic
;
3074 case PERF_COUNT_CPU_MIGRATIONS
:
3075 if (!counter
->hw_event
.exclude_kernel
)
3076 pmu
= &perf_ops_cpu_migrations
;
3084 * Allocate and initialize a counter structure
3086 static struct perf_counter
*
3087 perf_counter_alloc(struct perf_counter_hw_event
*hw_event
,
3089 struct perf_counter_context
*ctx
,
3090 struct perf_counter
*group_leader
,
3093 const struct pmu
*pmu
;
3094 struct perf_counter
*counter
;
3095 struct hw_perf_counter
*hwc
;
3098 counter
= kzalloc(sizeof(*counter
), gfpflags
);
3100 return ERR_PTR(-ENOMEM
);
3103 * Single counters are their own group leaders, with an
3104 * empty sibling list:
3107 group_leader
= counter
;
3109 mutex_init(&counter
->mutex
);
3110 INIT_LIST_HEAD(&counter
->list_entry
);
3111 INIT_LIST_HEAD(&counter
->event_entry
);
3112 INIT_LIST_HEAD(&counter
->sibling_list
);
3113 init_waitqueue_head(&counter
->waitq
);
3115 mutex_init(&counter
->mmap_mutex
);
3117 INIT_LIST_HEAD(&counter
->child_list
);
3120 counter
->hw_event
= *hw_event
;
3121 counter
->group_leader
= group_leader
;
3122 counter
->pmu
= NULL
;
3126 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
3127 if (hw_event
->disabled
)
3128 counter
->state
= PERF_COUNTER_STATE_OFF
;
3133 if (hw_event
->freq
&& hw_event
->irq_freq
)
3134 hwc
->irq_period
= div64_u64(TICK_NSEC
, hw_event
->irq_freq
);
3136 hwc
->irq_period
= hw_event
->irq_period
;
3139 * we currently do not support PERF_RECORD_GROUP on inherited counters
3141 if (hw_event
->inherit
&& (hw_event
->record_type
& PERF_RECORD_GROUP
))
3144 if (perf_event_raw(hw_event
)) {
3145 pmu
= hw_perf_counter_init(counter
);
3149 switch (perf_event_type(hw_event
)) {
3150 case PERF_TYPE_HARDWARE
:
3151 pmu
= hw_perf_counter_init(counter
);
3154 case PERF_TYPE_SOFTWARE
:
3155 pmu
= sw_perf_counter_init(counter
);
3158 case PERF_TYPE_TRACEPOINT
:
3159 pmu
= tp_perf_counter_init(counter
);
3166 else if (IS_ERR(pmu
))
3171 return ERR_PTR(err
);
3176 atomic_inc(&nr_counters
);
3177 if (counter
->hw_event
.mmap
)
3178 atomic_inc(&nr_mmap_tracking
);
3179 if (counter
->hw_event
.munmap
)
3180 atomic_inc(&nr_munmap_tracking
);
3181 if (counter
->hw_event
.comm
)
3182 atomic_inc(&nr_comm_tracking
);
3188 * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
3190 * @hw_event_uptr: event type attributes for monitoring/sampling
3193 * @group_fd: group leader counter fd
3195 SYSCALL_DEFINE5(perf_counter_open
,
3196 const struct perf_counter_hw_event __user
*, hw_event_uptr
,
3197 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
3199 struct perf_counter
*counter
, *group_leader
;
3200 struct perf_counter_hw_event hw_event
;
3201 struct perf_counter_context
*ctx
;
3202 struct file
*counter_file
= NULL
;
3203 struct file
*group_file
= NULL
;
3204 int fput_needed
= 0;
3205 int fput_needed2
= 0;
3208 /* for future expandability... */
3212 if (copy_from_user(&hw_event
, hw_event_uptr
, sizeof(hw_event
)) != 0)
3216 * Get the target context (task or percpu):
3218 ctx
= find_get_context(pid
, cpu
);
3220 return PTR_ERR(ctx
);
3223 * Look up the group leader (we will attach this counter to it):
3225 group_leader
= NULL
;
3226 if (group_fd
!= -1) {
3228 group_file
= fget_light(group_fd
, &fput_needed
);
3230 goto err_put_context
;
3231 if (group_file
->f_op
!= &perf_fops
)
3232 goto err_put_context
;
3234 group_leader
= group_file
->private_data
;
3236 * Do not allow a recursive hierarchy (this new sibling
3237 * becoming part of another group-sibling):
3239 if (group_leader
->group_leader
!= group_leader
)
3240 goto err_put_context
;
3242 * Do not allow to attach to a group in a different
3243 * task or CPU context:
3245 if (group_leader
->ctx
!= ctx
)
3246 goto err_put_context
;
3248 * Only a group leader can be exclusive or pinned
3250 if (hw_event
.exclusive
|| hw_event
.pinned
)
3251 goto err_put_context
;
3254 counter
= perf_counter_alloc(&hw_event
, cpu
, ctx
, group_leader
,
3256 ret
= PTR_ERR(counter
);
3257 if (IS_ERR(counter
))
3258 goto err_put_context
;
3260 ret
= anon_inode_getfd("[perf_counter]", &perf_fops
, counter
, 0);
3262 goto err_free_put_context
;
3264 counter_file
= fget_light(ret
, &fput_needed2
);
3266 goto err_free_put_context
;
3268 counter
->filp
= counter_file
;
3269 mutex_lock(&ctx
->mutex
);
3270 perf_install_in_context(ctx
, counter
, cpu
);
3271 mutex_unlock(&ctx
->mutex
);
3273 fput_light(counter_file
, fput_needed2
);
3276 fput_light(group_file
, fput_needed
);
3280 err_free_put_context
:
3290 * inherit a counter from parent task to child task:
3292 static struct perf_counter
*
3293 inherit_counter(struct perf_counter
*parent_counter
,
3294 struct task_struct
*parent
,
3295 struct perf_counter_context
*parent_ctx
,
3296 struct task_struct
*child
,
3297 struct perf_counter
*group_leader
,
3298 struct perf_counter_context
*child_ctx
)
3300 struct perf_counter
*child_counter
;
3303 * Instead of creating recursive hierarchies of counters,
3304 * we link inherited counters back to the original parent,
3305 * which has a filp for sure, which we use as the reference
3308 if (parent_counter
->parent
)
3309 parent_counter
= parent_counter
->parent
;
3311 child_counter
= perf_counter_alloc(&parent_counter
->hw_event
,
3312 parent_counter
->cpu
, child_ctx
,
3313 group_leader
, GFP_KERNEL
);
3314 if (IS_ERR(child_counter
))
3315 return child_counter
;
3318 * Make the child state follow the state of the parent counter,
3319 * not its hw_event.disabled bit. We hold the parent's mutex,
3320 * so we won't race with perf_counter_{en,dis}able_family.
3322 if (parent_counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
3323 child_counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
3325 child_counter
->state
= PERF_COUNTER_STATE_OFF
;
3328 * Link it up in the child's context:
3330 add_counter_to_ctx(child_counter
, child_ctx
);
3332 child_counter
->parent
= parent_counter
;
3334 * inherit into child's child as well:
3336 child_counter
->hw_event
.inherit
= 1;
3339 * Get a reference to the parent filp - we will fput it
3340 * when the child counter exits. This is safe to do because
3341 * we are in the parent and we know that the filp still
3342 * exists and has a nonzero count:
3344 atomic_long_inc(&parent_counter
->filp
->f_count
);
3347 * Link this into the parent counter's child list
3349 mutex_lock(&parent_counter
->mutex
);
3350 list_add_tail(&child_counter
->child_list
, &parent_counter
->child_list
);
3352 mutex_unlock(&parent_counter
->mutex
);
3354 return child_counter
;
3357 static int inherit_group(struct perf_counter
*parent_counter
,
3358 struct task_struct
*parent
,
3359 struct perf_counter_context
*parent_ctx
,
3360 struct task_struct
*child
,
3361 struct perf_counter_context
*child_ctx
)
3363 struct perf_counter
*leader
;
3364 struct perf_counter
*sub
;
3365 struct perf_counter
*child_ctr
;
3367 leader
= inherit_counter(parent_counter
, parent
, parent_ctx
,
3368 child
, NULL
, child_ctx
);
3370 return PTR_ERR(leader
);
3371 list_for_each_entry(sub
, &parent_counter
->sibling_list
, list_entry
) {
3372 child_ctr
= inherit_counter(sub
, parent
, parent_ctx
,
3373 child
, leader
, child_ctx
);
3374 if (IS_ERR(child_ctr
))
3375 return PTR_ERR(child_ctr
);
3380 static void sync_child_counter(struct perf_counter
*child_counter
,
3381 struct perf_counter
*parent_counter
)
3385 child_val
= atomic64_read(&child_counter
->count
);
3388 * Add back the child's count to the parent's count:
3390 atomic64_add(child_val
, &parent_counter
->count
);
3391 atomic64_add(child_counter
->total_time_enabled
,
3392 &parent_counter
->child_total_time_enabled
);
3393 atomic64_add(child_counter
->total_time_running
,
3394 &parent_counter
->child_total_time_running
);
3397 * Remove this counter from the parent's list
3399 mutex_lock(&parent_counter
->mutex
);
3400 list_del_init(&child_counter
->child_list
);
3401 mutex_unlock(&parent_counter
->mutex
);
3404 * Release the parent counter, if this was the last
3407 fput(parent_counter
->filp
);
3411 __perf_counter_exit_task(struct task_struct
*child
,
3412 struct perf_counter
*child_counter
,
3413 struct perf_counter_context
*child_ctx
)
3415 struct perf_counter
*parent_counter
;
3418 * Protect against concurrent operations on child_counter
3419 * due its fd getting closed, etc.
3421 mutex_lock(&child_counter
->mutex
);
3423 update_counter_times(child_counter
);
3424 list_del_counter(child_counter
, child_ctx
);
3426 mutex_unlock(&child_counter
->mutex
);
3428 parent_counter
= child_counter
->parent
;
3430 * It can happen that parent exits first, and has counters
3431 * that are still around due to the child reference. These
3432 * counters need to be zapped - but otherwise linger.
3434 if (parent_counter
) {
3435 sync_child_counter(child_counter
, parent_counter
);
3436 free_counter(child_counter
);
3441 * When a child task exits, feed back counter values to parent counters.
3443 * Note: we may be running in child context, but the PID is not hashed
3444 * anymore so new counters will not be added.
3445 * (XXX not sure that is true when we get called from flush_old_exec.
3448 void perf_counter_exit_task(struct task_struct
*child
)
3450 struct perf_counter
*child_counter
, *tmp
;
3451 struct perf_counter_context
*child_ctx
;
3452 unsigned long flags
;
3454 WARN_ON_ONCE(child
!= current
);
3456 child_ctx
= child
->perf_counter_ctxp
;
3458 if (likely(!child_ctx
))
3461 local_irq_save(flags
);
3462 __perf_counter_task_sched_out(child_ctx
);
3463 child
->perf_counter_ctxp
= NULL
;
3464 local_irq_restore(flags
);
3466 mutex_lock(&child_ctx
->mutex
);
3469 list_for_each_entry_safe(child_counter
, tmp
, &child_ctx
->counter_list
,
3471 __perf_counter_exit_task(child
, child_counter
, child_ctx
);
3474 * If the last counter was a group counter, it will have appended all
3475 * its siblings to the list, but we obtained 'tmp' before that which
3476 * will still point to the list head terminating the iteration.
3478 if (!list_empty(&child_ctx
->counter_list
))
3481 mutex_unlock(&child_ctx
->mutex
);
3487 * Initialize the perf_counter context in task_struct
3489 void perf_counter_init_task(struct task_struct
*child
)
3491 struct perf_counter_context
*child_ctx
, *parent_ctx
;
3492 struct perf_counter
*counter
;
3493 struct task_struct
*parent
= current
;
3494 int inherited_all
= 1;
3496 child
->perf_counter_ctxp
= NULL
;
3499 * This is executed from the parent task context, so inherit
3500 * counters that have been marked for cloning.
3501 * First allocate and initialize a context for the child.
3504 child_ctx
= kmalloc(sizeof(struct perf_counter_context
), GFP_KERNEL
);
3508 parent_ctx
= parent
->perf_counter_ctxp
;
3509 if (likely(!parent_ctx
|| !parent_ctx
->nr_counters
))
3512 __perf_counter_init_context(child_ctx
, child
);
3513 child
->perf_counter_ctxp
= child_ctx
;
3516 * Lock the parent list. No need to lock the child - not PID
3517 * hashed yet and not running, so nobody can access it.
3519 mutex_lock(&parent_ctx
->mutex
);
3522 * We dont have to disable NMIs - we are only looking at
3523 * the list, not manipulating it:
3525 list_for_each_entry_rcu(counter
, &parent_ctx
->event_list
, event_entry
) {
3526 if (counter
!= counter
->group_leader
)
3529 if (!counter
->hw_event
.inherit
) {
3534 if (inherit_group(counter
, parent
,
3535 parent_ctx
, child
, child_ctx
)) {
3541 if (inherited_all
) {
3543 * Mark the child context as a clone of the parent
3544 * context, or of whatever the parent is a clone of.
3546 if (parent_ctx
->parent_ctx
) {
3547 child_ctx
->parent_ctx
= parent_ctx
->parent_ctx
;
3548 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
3550 child_ctx
->parent_ctx
= parent_ctx
;
3551 child_ctx
->parent_gen
= parent_ctx
->generation
;
3553 get_ctx(child_ctx
->parent_ctx
);
3556 mutex_unlock(&parent_ctx
->mutex
);
3559 static void __cpuinit
perf_counter_init_cpu(int cpu
)
3561 struct perf_cpu_context
*cpuctx
;
3563 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3564 __perf_counter_init_context(&cpuctx
->ctx
, NULL
);
3566 spin_lock(&perf_resource_lock
);
3567 cpuctx
->max_pertask
= perf_max_counters
- perf_reserved_percpu
;
3568 spin_unlock(&perf_resource_lock
);
3570 hw_perf_counter_setup(cpu
);
3573 #ifdef CONFIG_HOTPLUG_CPU
3574 static void __perf_counter_exit_cpu(void *info
)
3576 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
3577 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3578 struct perf_counter
*counter
, *tmp
;
3580 list_for_each_entry_safe(counter
, tmp
, &ctx
->counter_list
, list_entry
)
3581 __perf_counter_remove_from_context(counter
);
3583 static void perf_counter_exit_cpu(int cpu
)
3585 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3586 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3588 mutex_lock(&ctx
->mutex
);
3589 smp_call_function_single(cpu
, __perf_counter_exit_cpu
, NULL
, 1);
3590 mutex_unlock(&ctx
->mutex
);
3593 static inline void perf_counter_exit_cpu(int cpu
) { }
3596 static int __cpuinit
3597 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
3599 unsigned int cpu
= (long)hcpu
;
3603 case CPU_UP_PREPARE
:
3604 case CPU_UP_PREPARE_FROZEN
:
3605 perf_counter_init_cpu(cpu
);
3608 case CPU_DOWN_PREPARE
:
3609 case CPU_DOWN_PREPARE_FROZEN
:
3610 perf_counter_exit_cpu(cpu
);
3620 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
3621 .notifier_call
= perf_cpu_notify
,
3624 void __init
perf_counter_init(void)
3626 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
3627 (void *)(long)smp_processor_id());
3628 register_cpu_notifier(&perf_cpu_nb
);
3631 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class, char *buf
)
3633 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
3637 perf_set_reserve_percpu(struct sysdev_class
*class,
3641 struct perf_cpu_context
*cpuctx
;
3645 err
= strict_strtoul(buf
, 10, &val
);
3648 if (val
> perf_max_counters
)
3651 spin_lock(&perf_resource_lock
);
3652 perf_reserved_percpu
= val
;
3653 for_each_online_cpu(cpu
) {
3654 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3655 spin_lock_irq(&cpuctx
->ctx
.lock
);
3656 mpt
= min(perf_max_counters
- cpuctx
->ctx
.nr_counters
,
3657 perf_max_counters
- perf_reserved_percpu
);
3658 cpuctx
->max_pertask
= mpt
;
3659 spin_unlock_irq(&cpuctx
->ctx
.lock
);
3661 spin_unlock(&perf_resource_lock
);
3666 static ssize_t
perf_show_overcommit(struct sysdev_class
*class, char *buf
)
3668 return sprintf(buf
, "%d\n", perf_overcommit
);
3672 perf_set_overcommit(struct sysdev_class
*class, const char *buf
, size_t count
)
3677 err
= strict_strtoul(buf
, 10, &val
);
3683 spin_lock(&perf_resource_lock
);
3684 perf_overcommit
= val
;
3685 spin_unlock(&perf_resource_lock
);
3690 static SYSDEV_CLASS_ATTR(
3693 perf_show_reserve_percpu
,
3694 perf_set_reserve_percpu
3697 static SYSDEV_CLASS_ATTR(
3700 perf_show_overcommit
,
3704 static struct attribute
*perfclass_attrs
[] = {
3705 &attr_reserve_percpu
.attr
,
3706 &attr_overcommit
.attr
,
3710 static struct attribute_group perfclass_attr_group
= {
3711 .attrs
= perfclass_attrs
,
3712 .name
= "perf_counters",
3715 static int __init
perf_counter_sysfs_init(void)
3717 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
3718 &perfclass_attr_group
);
3720 device_initcall(perf_counter_sysfs_init
);