2 * Performance counter core code
4 * Copyright(C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright(C) 2008 Red Hat, Inc., Ingo Molnar
8 * For licensing details see kernel-base/COPYING
13 #include <linux/cpu.h>
14 #include <linux/smp.h>
15 #include <linux/file.h>
16 #include <linux/poll.h>
17 #include <linux/sysfs.h>
18 #include <linux/ptrace.h>
19 #include <linux/percpu.h>
20 #include <linux/vmstat.h>
21 #include <linux/hardirq.h>
22 #include <linux/rculist.h>
23 #include <linux/uaccess.h>
24 #include <linux/syscalls.h>
25 #include <linux/anon_inodes.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/perf_counter.h>
28 #include <linux/dcache.h>
30 #include <asm/irq_regs.h>
33 * Each CPU has a list of per CPU counters:
35 DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
37 int perf_max_counters __read_mostly
= 1;
38 static int perf_reserved_percpu __read_mostly
;
39 static int perf_overcommit __read_mostly
= 1;
41 static atomic_t nr_mmap_tracking __read_mostly
;
42 static atomic_t nr_munmap_tracking __read_mostly
;
43 static atomic_t nr_comm_tracking __read_mostly
;
45 int sysctl_perf_counter_priv __read_mostly
; /* do we need to be privileged */
48 * Mutex for (sysadmin-configurable) counter reservations:
50 static DEFINE_MUTEX(perf_resource_mutex
);
53 * Architecture provided APIs - weak aliases:
55 extern __weak
const struct hw_perf_counter_ops
*
56 hw_perf_counter_init(struct perf_counter
*counter
)
61 u64 __weak
hw_perf_save_disable(void) { return 0; }
62 void __weak
hw_perf_restore(u64 ctrl
) { barrier(); }
63 void __weak
hw_perf_counter_setup(int cpu
) { barrier(); }
64 int __weak
hw_perf_group_sched_in(struct perf_counter
*group_leader
,
65 struct perf_cpu_context
*cpuctx
,
66 struct perf_counter_context
*ctx
, int cpu
)
71 void __weak
perf_counter_print_debug(void) { }
74 list_add_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
76 struct perf_counter
*group_leader
= counter
->group_leader
;
79 * Depending on whether it is a standalone or sibling counter,
80 * add it straight to the context's counter list, or to the group
81 * leader's sibling list:
83 if (counter
->group_leader
== counter
)
84 list_add_tail(&counter
->list_entry
, &ctx
->counter_list
);
86 list_add_tail(&counter
->list_entry
, &group_leader
->sibling_list
);
87 group_leader
->nr_siblings
++;
90 list_add_rcu(&counter
->event_entry
, &ctx
->event_list
);
94 list_del_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
96 struct perf_counter
*sibling
, *tmp
;
98 list_del_init(&counter
->list_entry
);
99 list_del_rcu(&counter
->event_entry
);
101 if (counter
->group_leader
!= counter
)
102 counter
->group_leader
->nr_siblings
--;
105 * If this was a group counter with sibling counters then
106 * upgrade the siblings to singleton counters by adding them
107 * to the context list directly:
109 list_for_each_entry_safe(sibling
, tmp
,
110 &counter
->sibling_list
, list_entry
) {
112 list_move_tail(&sibling
->list_entry
, &ctx
->counter_list
);
113 sibling
->group_leader
= sibling
;
118 counter_sched_out(struct perf_counter
*counter
,
119 struct perf_cpu_context
*cpuctx
,
120 struct perf_counter_context
*ctx
)
122 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
125 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
126 counter
->tstamp_stopped
= ctx
->time
;
127 counter
->hw_ops
->disable(counter
);
130 if (!is_software_counter(counter
))
131 cpuctx
->active_oncpu
--;
133 if (counter
->hw_event
.exclusive
|| !cpuctx
->active_oncpu
)
134 cpuctx
->exclusive
= 0;
138 group_sched_out(struct perf_counter
*group_counter
,
139 struct perf_cpu_context
*cpuctx
,
140 struct perf_counter_context
*ctx
)
142 struct perf_counter
*counter
;
144 if (group_counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
147 counter_sched_out(group_counter
, cpuctx
, ctx
);
150 * Schedule out siblings (if any):
152 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
)
153 counter_sched_out(counter
, cpuctx
, ctx
);
155 if (group_counter
->hw_event
.exclusive
)
156 cpuctx
->exclusive
= 0;
160 * Cross CPU call to remove a performance counter
162 * We disable the counter on the hardware level first. After that we
163 * remove it from the context list.
165 static void __perf_counter_remove_from_context(void *info
)
167 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
168 struct perf_counter
*counter
= info
;
169 struct perf_counter_context
*ctx
= counter
->ctx
;
174 * If this is a task context, we need to check whether it is
175 * the current task context of this cpu. If not it has been
176 * scheduled out before the smp call arrived.
178 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
181 spin_lock_irqsave(&ctx
->lock
, flags
);
183 counter_sched_out(counter
, cpuctx
, ctx
);
185 counter
->task
= NULL
;
189 * Protect the list operation against NMI by disabling the
190 * counters on a global level. NOP for non NMI based counters.
192 perf_flags
= hw_perf_save_disable();
193 list_del_counter(counter
, ctx
);
194 hw_perf_restore(perf_flags
);
198 * Allow more per task counters with respect to the
201 cpuctx
->max_pertask
=
202 min(perf_max_counters
- ctx
->nr_counters
,
203 perf_max_counters
- perf_reserved_percpu
);
206 spin_unlock_irqrestore(&ctx
->lock
, flags
);
211 * Remove the counter from a task's (or a CPU's) list of counters.
213 * Must be called with counter->mutex and ctx->mutex held.
215 * CPU counters are removed with a smp call. For task counters we only
216 * call when the task is on a CPU.
218 static void perf_counter_remove_from_context(struct perf_counter
*counter
)
220 struct perf_counter_context
*ctx
= counter
->ctx
;
221 struct task_struct
*task
= ctx
->task
;
225 * Per cpu counters are removed via an smp call and
226 * the removal is always sucessful.
228 smp_call_function_single(counter
->cpu
,
229 __perf_counter_remove_from_context
,
235 task_oncpu_function_call(task
, __perf_counter_remove_from_context
,
238 spin_lock_irq(&ctx
->lock
);
240 * If the context is active we need to retry the smp call.
242 if (ctx
->nr_active
&& !list_empty(&counter
->list_entry
)) {
243 spin_unlock_irq(&ctx
->lock
);
248 * The lock prevents that this context is scheduled in so we
249 * can remove the counter safely, if the call above did not
252 if (!list_empty(&counter
->list_entry
)) {
254 list_del_counter(counter
, ctx
);
255 counter
->task
= NULL
;
257 spin_unlock_irq(&ctx
->lock
);
260 static inline u64
perf_clock(void)
262 return cpu_clock(smp_processor_id());
266 * Update the record of the current time in a context.
268 static void update_context_time(struct perf_counter_context
*ctx
)
270 u64 now
= perf_clock();
272 ctx
->time
+= now
- ctx
->timestamp
;
273 ctx
->timestamp
= now
;
277 * Update the total_time_enabled and total_time_running fields for a counter.
279 static void update_counter_times(struct perf_counter
*counter
)
281 struct perf_counter_context
*ctx
= counter
->ctx
;
284 if (counter
->state
< PERF_COUNTER_STATE_INACTIVE
)
287 counter
->total_time_enabled
= ctx
->time
- counter
->tstamp_enabled
;
289 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
)
290 run_end
= counter
->tstamp_stopped
;
294 counter
->total_time_running
= run_end
- counter
->tstamp_running
;
298 * Update total_time_enabled and total_time_running for all counters in a group.
300 static void update_group_times(struct perf_counter
*leader
)
302 struct perf_counter
*counter
;
304 update_counter_times(leader
);
305 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
306 update_counter_times(counter
);
310 * Cross CPU call to disable a performance counter
312 static void __perf_counter_disable(void *info
)
314 struct perf_counter
*counter
= info
;
315 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
316 struct perf_counter_context
*ctx
= counter
->ctx
;
320 * If this is a per-task counter, need to check whether this
321 * counter's task is the current task on this cpu.
323 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
326 spin_lock_irqsave(&ctx
->lock
, flags
);
329 * If the counter is on, turn it off.
330 * If it is in error state, leave it in error state.
332 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
) {
333 update_context_time(ctx
);
334 update_counter_times(counter
);
335 if (counter
== counter
->group_leader
)
336 group_sched_out(counter
, cpuctx
, ctx
);
338 counter_sched_out(counter
, cpuctx
, ctx
);
339 counter
->state
= PERF_COUNTER_STATE_OFF
;
342 spin_unlock_irqrestore(&ctx
->lock
, flags
);
348 static void perf_counter_disable(struct perf_counter
*counter
)
350 struct perf_counter_context
*ctx
= counter
->ctx
;
351 struct task_struct
*task
= ctx
->task
;
355 * Disable the counter on the cpu that it's on
357 smp_call_function_single(counter
->cpu
, __perf_counter_disable
,
363 task_oncpu_function_call(task
, __perf_counter_disable
, counter
);
365 spin_lock_irq(&ctx
->lock
);
367 * If the counter is still active, we need to retry the cross-call.
369 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
370 spin_unlock_irq(&ctx
->lock
);
375 * Since we have the lock this context can't be scheduled
376 * in, so we can change the state safely.
378 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
379 update_counter_times(counter
);
380 counter
->state
= PERF_COUNTER_STATE_OFF
;
383 spin_unlock_irq(&ctx
->lock
);
387 * Disable a counter and all its children.
389 static void perf_counter_disable_family(struct perf_counter
*counter
)
391 struct perf_counter
*child
;
393 perf_counter_disable(counter
);
396 * Lock the mutex to protect the list of children
398 mutex_lock(&counter
->mutex
);
399 list_for_each_entry(child
, &counter
->child_list
, child_list
)
400 perf_counter_disable(child
);
401 mutex_unlock(&counter
->mutex
);
405 counter_sched_in(struct perf_counter
*counter
,
406 struct perf_cpu_context
*cpuctx
,
407 struct perf_counter_context
*ctx
,
410 if (counter
->state
<= PERF_COUNTER_STATE_OFF
)
413 counter
->state
= PERF_COUNTER_STATE_ACTIVE
;
414 counter
->oncpu
= cpu
; /* TODO: put 'cpu' into cpuctx->cpu */
416 * The new state must be visible before we turn it on in the hardware:
420 if (counter
->hw_ops
->enable(counter
)) {
421 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
426 counter
->tstamp_running
+= ctx
->time
- counter
->tstamp_stopped
;
428 if (!is_software_counter(counter
))
429 cpuctx
->active_oncpu
++;
432 if (counter
->hw_event
.exclusive
)
433 cpuctx
->exclusive
= 1;
439 * Return 1 for a group consisting entirely of software counters,
440 * 0 if the group contains any hardware counters.
442 static int is_software_only_group(struct perf_counter
*leader
)
444 struct perf_counter
*counter
;
446 if (!is_software_counter(leader
))
449 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
450 if (!is_software_counter(counter
))
457 * Work out whether we can put this counter group on the CPU now.
459 static int group_can_go_on(struct perf_counter
*counter
,
460 struct perf_cpu_context
*cpuctx
,
464 * Groups consisting entirely of software counters can always go on.
466 if (is_software_only_group(counter
))
469 * If an exclusive group is already on, no other hardware
470 * counters can go on.
472 if (cpuctx
->exclusive
)
475 * If this group is exclusive and there are already
476 * counters on the CPU, it can't go on.
478 if (counter
->hw_event
.exclusive
&& cpuctx
->active_oncpu
)
481 * Otherwise, try to add it if all previous groups were able
487 static void add_counter_to_ctx(struct perf_counter
*counter
,
488 struct perf_counter_context
*ctx
)
490 list_add_counter(counter
, ctx
);
492 counter
->prev_state
= PERF_COUNTER_STATE_OFF
;
493 counter
->tstamp_enabled
= ctx
->time
;
494 counter
->tstamp_running
= ctx
->time
;
495 counter
->tstamp_stopped
= ctx
->time
;
499 * Cross CPU call to install and enable a performance counter
501 static void __perf_install_in_context(void *info
)
503 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
504 struct perf_counter
*counter
= info
;
505 struct perf_counter_context
*ctx
= counter
->ctx
;
506 struct perf_counter
*leader
= counter
->group_leader
;
507 int cpu
= smp_processor_id();
513 * If this is a task context, we need to check whether it is
514 * the current task context of this cpu. If not it has been
515 * scheduled out before the smp call arrived.
517 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
520 spin_lock_irqsave(&ctx
->lock
, flags
);
521 update_context_time(ctx
);
524 * Protect the list operation against NMI by disabling the
525 * counters on a global level. NOP for non NMI based counters.
527 perf_flags
= hw_perf_save_disable();
529 add_counter_to_ctx(counter
, ctx
);
532 * Don't put the counter on if it is disabled or if
533 * it is in a group and the group isn't on.
535 if (counter
->state
!= PERF_COUNTER_STATE_INACTIVE
||
536 (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
))
540 * An exclusive counter can't go on if there are already active
541 * hardware counters, and no hardware counter can go on if there
542 * is already an exclusive counter on.
544 if (!group_can_go_on(counter
, cpuctx
, 1))
547 err
= counter_sched_in(counter
, cpuctx
, ctx
, cpu
);
551 * This counter couldn't go on. If it is in a group
552 * then we have to pull the whole group off.
553 * If the counter group is pinned then put it in error state.
555 if (leader
!= counter
)
556 group_sched_out(leader
, cpuctx
, ctx
);
557 if (leader
->hw_event
.pinned
) {
558 update_group_times(leader
);
559 leader
->state
= PERF_COUNTER_STATE_ERROR
;
563 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
564 cpuctx
->max_pertask
--;
567 hw_perf_restore(perf_flags
);
569 spin_unlock_irqrestore(&ctx
->lock
, flags
);
573 * Attach a performance counter to a context
575 * First we add the counter to the list with the hardware enable bit
576 * in counter->hw_config cleared.
578 * If the counter is attached to a task which is on a CPU we use a smp
579 * call to enable it in the task context. The task might have been
580 * scheduled away, but we check this in the smp call again.
582 * Must be called with ctx->mutex held.
585 perf_install_in_context(struct perf_counter_context
*ctx
,
586 struct perf_counter
*counter
,
589 struct task_struct
*task
= ctx
->task
;
593 * Per cpu counters are installed via an smp call and
594 * the install is always sucessful.
596 smp_call_function_single(cpu
, __perf_install_in_context
,
601 counter
->task
= task
;
603 task_oncpu_function_call(task
, __perf_install_in_context
,
606 spin_lock_irq(&ctx
->lock
);
608 * we need to retry the smp call.
610 if (ctx
->is_active
&& list_empty(&counter
->list_entry
)) {
611 spin_unlock_irq(&ctx
->lock
);
616 * The lock prevents that this context is scheduled in so we
617 * can add the counter safely, if it the call above did not
620 if (list_empty(&counter
->list_entry
))
621 add_counter_to_ctx(counter
, ctx
);
622 spin_unlock_irq(&ctx
->lock
);
626 * Cross CPU call to enable a performance counter
628 static void __perf_counter_enable(void *info
)
630 struct perf_counter
*counter
= info
;
631 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
632 struct perf_counter_context
*ctx
= counter
->ctx
;
633 struct perf_counter
*leader
= counter
->group_leader
;
638 * If this is a per-task counter, need to check whether this
639 * counter's task is the current task on this cpu.
641 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
644 spin_lock_irqsave(&ctx
->lock
, flags
);
645 update_context_time(ctx
);
647 counter
->prev_state
= counter
->state
;
648 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
650 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
651 counter
->tstamp_enabled
= ctx
->time
- counter
->total_time_enabled
;
654 * If the counter is in a group and isn't the group leader,
655 * then don't put it on unless the group is on.
657 if (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
)
660 if (!group_can_go_on(counter
, cpuctx
, 1))
663 err
= counter_sched_in(counter
, cpuctx
, ctx
,
668 * If this counter can't go on and it's part of a
669 * group, then the whole group has to come off.
671 if (leader
!= counter
)
672 group_sched_out(leader
, cpuctx
, ctx
);
673 if (leader
->hw_event
.pinned
) {
674 update_group_times(leader
);
675 leader
->state
= PERF_COUNTER_STATE_ERROR
;
680 spin_unlock_irqrestore(&ctx
->lock
, flags
);
686 static void perf_counter_enable(struct perf_counter
*counter
)
688 struct perf_counter_context
*ctx
= counter
->ctx
;
689 struct task_struct
*task
= ctx
->task
;
693 * Enable the counter on the cpu that it's on
695 smp_call_function_single(counter
->cpu
, __perf_counter_enable
,
700 spin_lock_irq(&ctx
->lock
);
701 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
705 * If the counter is in error state, clear that first.
706 * That way, if we see the counter in error state below, we
707 * know that it has gone back into error state, as distinct
708 * from the task having been scheduled away before the
709 * cross-call arrived.
711 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
712 counter
->state
= PERF_COUNTER_STATE_OFF
;
715 spin_unlock_irq(&ctx
->lock
);
716 task_oncpu_function_call(task
, __perf_counter_enable
, counter
);
718 spin_lock_irq(&ctx
->lock
);
721 * If the context is active and the counter is still off,
722 * we need to retry the cross-call.
724 if (ctx
->is_active
&& counter
->state
== PERF_COUNTER_STATE_OFF
)
728 * Since we have the lock this context can't be scheduled
729 * in, so we can change the state safely.
731 if (counter
->state
== PERF_COUNTER_STATE_OFF
) {
732 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
733 counter
->tstamp_enabled
=
734 ctx
->time
- counter
->total_time_enabled
;
737 spin_unlock_irq(&ctx
->lock
);
740 static void perf_counter_refresh(struct perf_counter
*counter
, int refresh
)
742 atomic_add(refresh
, &counter
->event_limit
);
743 perf_counter_enable(counter
);
747 * Enable a counter and all its children.
749 static void perf_counter_enable_family(struct perf_counter
*counter
)
751 struct perf_counter
*child
;
753 perf_counter_enable(counter
);
756 * Lock the mutex to protect the list of children
758 mutex_lock(&counter
->mutex
);
759 list_for_each_entry(child
, &counter
->child_list
, child_list
)
760 perf_counter_enable(child
);
761 mutex_unlock(&counter
->mutex
);
764 void __perf_counter_sched_out(struct perf_counter_context
*ctx
,
765 struct perf_cpu_context
*cpuctx
)
767 struct perf_counter
*counter
;
770 spin_lock(&ctx
->lock
);
772 if (likely(!ctx
->nr_counters
))
774 update_context_time(ctx
);
776 flags
= hw_perf_save_disable();
777 if (ctx
->nr_active
) {
778 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
)
779 group_sched_out(counter
, cpuctx
, ctx
);
781 hw_perf_restore(flags
);
783 spin_unlock(&ctx
->lock
);
787 * Called from scheduler to remove the counters of the current task,
788 * with interrupts disabled.
790 * We stop each counter and update the counter value in counter->count.
792 * This does not protect us against NMI, but disable()
793 * sets the disabled bit in the control field of counter _before_
794 * accessing the counter control register. If a NMI hits, then it will
795 * not restart the counter.
797 void perf_counter_task_sched_out(struct task_struct
*task
, int cpu
)
799 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
800 struct perf_counter_context
*ctx
= &task
->perf_counter_ctx
;
801 struct pt_regs
*regs
;
803 if (likely(!cpuctx
->task_ctx
))
806 update_context_time(ctx
);
808 regs
= task_pt_regs(task
);
809 perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES
, 1, 1, regs
, 0);
810 __perf_counter_sched_out(ctx
, cpuctx
);
812 cpuctx
->task_ctx
= NULL
;
815 static void perf_counter_cpu_sched_out(struct perf_cpu_context
*cpuctx
)
817 __perf_counter_sched_out(&cpuctx
->ctx
, cpuctx
);
821 group_sched_in(struct perf_counter
*group_counter
,
822 struct perf_cpu_context
*cpuctx
,
823 struct perf_counter_context
*ctx
,
826 struct perf_counter
*counter
, *partial_group
;
829 if (group_counter
->state
== PERF_COUNTER_STATE_OFF
)
832 ret
= hw_perf_group_sched_in(group_counter
, cpuctx
, ctx
, cpu
);
834 return ret
< 0 ? ret
: 0;
836 group_counter
->prev_state
= group_counter
->state
;
837 if (counter_sched_in(group_counter
, cpuctx
, ctx
, cpu
))
841 * Schedule in siblings as one group (if any):
843 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
844 counter
->prev_state
= counter
->state
;
845 if (counter_sched_in(counter
, cpuctx
, ctx
, cpu
)) {
846 partial_group
= counter
;
855 * Groups can be scheduled in as one unit only, so undo any
856 * partial group before returning:
858 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
859 if (counter
== partial_group
)
861 counter_sched_out(counter
, cpuctx
, ctx
);
863 counter_sched_out(group_counter
, cpuctx
, ctx
);
869 __perf_counter_sched_in(struct perf_counter_context
*ctx
,
870 struct perf_cpu_context
*cpuctx
, int cpu
)
872 struct perf_counter
*counter
;
876 spin_lock(&ctx
->lock
);
878 if (likely(!ctx
->nr_counters
))
881 ctx
->timestamp
= perf_clock();
883 flags
= hw_perf_save_disable();
886 * First go through the list and put on any pinned groups
887 * in order to give them the best chance of going on.
889 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
890 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
891 !counter
->hw_event
.pinned
)
893 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
896 if (group_can_go_on(counter
, cpuctx
, 1))
897 group_sched_in(counter
, cpuctx
, ctx
, cpu
);
900 * If this pinned group hasn't been scheduled,
901 * put it in error state.
903 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
904 update_group_times(counter
);
905 counter
->state
= PERF_COUNTER_STATE_ERROR
;
909 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
911 * Ignore counters in OFF or ERROR state, and
912 * ignore pinned counters since we did them already.
914 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
915 counter
->hw_event
.pinned
)
919 * Listen to the 'cpu' scheduling filter constraint
922 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
925 if (group_can_go_on(counter
, cpuctx
, can_add_hw
)) {
926 if (group_sched_in(counter
, cpuctx
, ctx
, cpu
))
930 hw_perf_restore(flags
);
932 spin_unlock(&ctx
->lock
);
936 * Called from scheduler to add the counters of the current task
937 * with interrupts disabled.
939 * We restore the counter value and then enable it.
941 * This does not protect us against NMI, but enable()
942 * sets the enabled bit in the control field of counter _before_
943 * accessing the counter control register. If a NMI hits, then it will
944 * keep the counter running.
946 void perf_counter_task_sched_in(struct task_struct
*task
, int cpu
)
948 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
949 struct perf_counter_context
*ctx
= &task
->perf_counter_ctx
;
951 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
952 cpuctx
->task_ctx
= ctx
;
955 static void perf_counter_cpu_sched_in(struct perf_cpu_context
*cpuctx
, int cpu
)
957 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
959 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
962 int perf_counter_task_disable(void)
964 struct task_struct
*curr
= current
;
965 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
966 struct perf_counter
*counter
;
971 if (likely(!ctx
->nr_counters
))
974 local_irq_save(flags
);
975 cpu
= smp_processor_id();
977 perf_counter_task_sched_out(curr
, cpu
);
979 spin_lock(&ctx
->lock
);
982 * Disable all the counters:
984 perf_flags
= hw_perf_save_disable();
986 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
987 if (counter
->state
!= PERF_COUNTER_STATE_ERROR
) {
988 update_group_times(counter
);
989 counter
->state
= PERF_COUNTER_STATE_OFF
;
993 hw_perf_restore(perf_flags
);
995 spin_unlock_irqrestore(&ctx
->lock
, flags
);
1000 int perf_counter_task_enable(void)
1002 struct task_struct
*curr
= current
;
1003 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
1004 struct perf_counter
*counter
;
1005 unsigned long flags
;
1009 if (likely(!ctx
->nr_counters
))
1012 local_irq_save(flags
);
1013 cpu
= smp_processor_id();
1015 perf_counter_task_sched_out(curr
, cpu
);
1017 spin_lock(&ctx
->lock
);
1020 * Disable all the counters:
1022 perf_flags
= hw_perf_save_disable();
1024 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1025 if (counter
->state
> PERF_COUNTER_STATE_OFF
)
1027 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
1028 counter
->tstamp_enabled
=
1029 ctx
->time
- counter
->total_time_enabled
;
1030 counter
->hw_event
.disabled
= 0;
1032 hw_perf_restore(perf_flags
);
1034 spin_unlock(&ctx
->lock
);
1036 perf_counter_task_sched_in(curr
, cpu
);
1038 local_irq_restore(flags
);
1044 * Round-robin a context's counters:
1046 static void rotate_ctx(struct perf_counter_context
*ctx
)
1048 struct perf_counter
*counter
;
1051 if (!ctx
->nr_counters
)
1054 spin_lock(&ctx
->lock
);
1056 * Rotate the first entry last (works just fine for group counters too):
1058 perf_flags
= hw_perf_save_disable();
1059 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1060 list_move_tail(&counter
->list_entry
, &ctx
->counter_list
);
1063 hw_perf_restore(perf_flags
);
1065 spin_unlock(&ctx
->lock
);
1068 void perf_counter_task_tick(struct task_struct
*curr
, int cpu
)
1070 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1071 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
1072 const int rotate_percpu
= 0;
1075 perf_counter_cpu_sched_out(cpuctx
);
1076 perf_counter_task_sched_out(curr
, cpu
);
1079 rotate_ctx(&cpuctx
->ctx
);
1083 perf_counter_cpu_sched_in(cpuctx
, cpu
);
1084 perf_counter_task_sched_in(curr
, cpu
);
1088 * Cross CPU call to read the hardware counter
1090 static void __read(void *info
)
1092 struct perf_counter
*counter
= info
;
1093 struct perf_counter_context
*ctx
= counter
->ctx
;
1094 unsigned long flags
;
1096 local_irq_save(flags
);
1098 update_context_time(ctx
);
1099 counter
->hw_ops
->read(counter
);
1100 update_counter_times(counter
);
1101 local_irq_restore(flags
);
1104 static u64
perf_counter_read(struct perf_counter
*counter
)
1107 * If counter is enabled and currently active on a CPU, update the
1108 * value in the counter structure:
1110 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
1111 smp_call_function_single(counter
->oncpu
,
1112 __read
, counter
, 1);
1113 } else if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
1114 update_counter_times(counter
);
1117 return atomic64_read(&counter
->count
);
1120 static void put_context(struct perf_counter_context
*ctx
)
1123 put_task_struct(ctx
->task
);
1126 static struct perf_counter_context
*find_get_context(pid_t pid
, int cpu
)
1128 struct perf_cpu_context
*cpuctx
;
1129 struct perf_counter_context
*ctx
;
1130 struct task_struct
*task
;
1133 * If cpu is not a wildcard then this is a percpu counter:
1136 /* Must be root to operate on a CPU counter: */
1137 if (sysctl_perf_counter_priv
&& !capable(CAP_SYS_ADMIN
))
1138 return ERR_PTR(-EACCES
);
1140 if (cpu
< 0 || cpu
> num_possible_cpus())
1141 return ERR_PTR(-EINVAL
);
1144 * We could be clever and allow to attach a counter to an
1145 * offline CPU and activate it when the CPU comes up, but
1148 if (!cpu_isset(cpu
, cpu_online_map
))
1149 return ERR_PTR(-ENODEV
);
1151 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1161 task
= find_task_by_vpid(pid
);
1163 get_task_struct(task
);
1167 return ERR_PTR(-ESRCH
);
1169 ctx
= &task
->perf_counter_ctx
;
1172 /* Reuse ptrace permission checks for now. */
1173 if (!ptrace_may_access(task
, PTRACE_MODE_READ
)) {
1175 return ERR_PTR(-EACCES
);
1181 static void free_counter_rcu(struct rcu_head
*head
)
1183 struct perf_counter
*counter
;
1185 counter
= container_of(head
, struct perf_counter
, rcu_head
);
1189 static void perf_pending_sync(struct perf_counter
*counter
);
1191 static void free_counter(struct perf_counter
*counter
)
1193 perf_pending_sync(counter
);
1195 if (counter
->hw_event
.mmap
)
1196 atomic_dec(&nr_mmap_tracking
);
1197 if (counter
->hw_event
.munmap
)
1198 atomic_dec(&nr_munmap_tracking
);
1199 if (counter
->hw_event
.comm
)
1200 atomic_dec(&nr_comm_tracking
);
1202 if (counter
->destroy
)
1203 counter
->destroy(counter
);
1205 call_rcu(&counter
->rcu_head
, free_counter_rcu
);
1209 * Called when the last reference to the file is gone.
1211 static int perf_release(struct inode
*inode
, struct file
*file
)
1213 struct perf_counter
*counter
= file
->private_data
;
1214 struct perf_counter_context
*ctx
= counter
->ctx
;
1216 file
->private_data
= NULL
;
1218 mutex_lock(&ctx
->mutex
);
1219 mutex_lock(&counter
->mutex
);
1221 perf_counter_remove_from_context(counter
);
1223 mutex_unlock(&counter
->mutex
);
1224 mutex_unlock(&ctx
->mutex
);
1226 free_counter(counter
);
1233 * Read the performance counter - simple non blocking version for now
1236 perf_read_hw(struct perf_counter
*counter
, char __user
*buf
, size_t count
)
1242 * Return end-of-file for a read on a counter that is in
1243 * error state (i.e. because it was pinned but it couldn't be
1244 * scheduled on to the CPU at some point).
1246 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
1249 mutex_lock(&counter
->mutex
);
1250 values
[0] = perf_counter_read(counter
);
1252 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1253 values
[n
++] = counter
->total_time_enabled
+
1254 atomic64_read(&counter
->child_total_time_enabled
);
1255 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1256 values
[n
++] = counter
->total_time_running
+
1257 atomic64_read(&counter
->child_total_time_running
);
1258 mutex_unlock(&counter
->mutex
);
1260 if (count
< n
* sizeof(u64
))
1262 count
= n
* sizeof(u64
);
1264 if (copy_to_user(buf
, values
, count
))
1271 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
1273 struct perf_counter
*counter
= file
->private_data
;
1275 return perf_read_hw(counter
, buf
, count
);
1278 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
1280 struct perf_counter
*counter
= file
->private_data
;
1281 struct perf_mmap_data
*data
;
1282 unsigned int events
;
1285 data
= rcu_dereference(counter
->data
);
1287 events
= atomic_xchg(&data
->wakeup
, 0);
1292 poll_wait(file
, &counter
->waitq
, wait
);
1297 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
1299 struct perf_counter
*counter
= file
->private_data
;
1303 case PERF_COUNTER_IOC_ENABLE
:
1304 perf_counter_enable_family(counter
);
1306 case PERF_COUNTER_IOC_DISABLE
:
1307 perf_counter_disable_family(counter
);
1309 case PERF_COUNTER_IOC_REFRESH
:
1310 perf_counter_refresh(counter
, arg
);
1319 * Callers need to ensure there can be no nesting of this function, otherwise
1320 * the seqlock logic goes bad. We can not serialize this because the arch
1321 * code calls this from NMI context.
1323 void perf_counter_update_userpage(struct perf_counter
*counter
)
1325 struct perf_mmap_data
*data
;
1326 struct perf_counter_mmap_page
*userpg
;
1329 data
= rcu_dereference(counter
->data
);
1333 userpg
= data
->user_page
;
1336 * Disable preemption so as to not let the corresponding user-space
1337 * spin too long if we get preempted.
1342 userpg
->index
= counter
->hw
.idx
;
1343 userpg
->offset
= atomic64_read(&counter
->count
);
1344 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
)
1345 userpg
->offset
-= atomic64_read(&counter
->hw
.prev_count
);
1354 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1356 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1357 struct perf_mmap_data
*data
;
1358 int ret
= VM_FAULT_SIGBUS
;
1361 data
= rcu_dereference(counter
->data
);
1365 if (vmf
->pgoff
== 0) {
1366 vmf
->page
= virt_to_page(data
->user_page
);
1368 int nr
= vmf
->pgoff
- 1;
1370 if ((unsigned)nr
> data
->nr_pages
)
1373 vmf
->page
= virt_to_page(data
->data_pages
[nr
]);
1375 get_page(vmf
->page
);
1383 static int perf_mmap_data_alloc(struct perf_counter
*counter
, int nr_pages
)
1385 struct perf_mmap_data
*data
;
1389 WARN_ON(atomic_read(&counter
->mmap_count
));
1391 size
= sizeof(struct perf_mmap_data
);
1392 size
+= nr_pages
* sizeof(void *);
1394 data
= kzalloc(size
, GFP_KERNEL
);
1398 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
1399 if (!data
->user_page
)
1400 goto fail_user_page
;
1402 for (i
= 0; i
< nr_pages
; i
++) {
1403 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
1404 if (!data
->data_pages
[i
])
1405 goto fail_data_pages
;
1408 data
->nr_pages
= nr_pages
;
1410 rcu_assign_pointer(counter
->data
, data
);
1415 for (i
--; i
>= 0; i
--)
1416 free_page((unsigned long)data
->data_pages
[i
]);
1418 free_page((unsigned long)data
->user_page
);
1427 static void __perf_mmap_data_free(struct rcu_head
*rcu_head
)
1429 struct perf_mmap_data
*data
= container_of(rcu_head
,
1430 struct perf_mmap_data
, rcu_head
);
1433 free_page((unsigned long)data
->user_page
);
1434 for (i
= 0; i
< data
->nr_pages
; i
++)
1435 free_page((unsigned long)data
->data_pages
[i
]);
1439 static void perf_mmap_data_free(struct perf_counter
*counter
)
1441 struct perf_mmap_data
*data
= counter
->data
;
1443 WARN_ON(atomic_read(&counter
->mmap_count
));
1445 rcu_assign_pointer(counter
->data
, NULL
);
1446 call_rcu(&data
->rcu_head
, __perf_mmap_data_free
);
1449 static void perf_mmap_open(struct vm_area_struct
*vma
)
1451 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1453 atomic_inc(&counter
->mmap_count
);
1456 static void perf_mmap_close(struct vm_area_struct
*vma
)
1458 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1460 if (atomic_dec_and_mutex_lock(&counter
->mmap_count
,
1461 &counter
->mmap_mutex
)) {
1462 vma
->vm_mm
->locked_vm
-= counter
->data
->nr_pages
+ 1;
1463 perf_mmap_data_free(counter
);
1464 mutex_unlock(&counter
->mmap_mutex
);
1468 static struct vm_operations_struct perf_mmap_vmops
= {
1469 .open
= perf_mmap_open
,
1470 .close
= perf_mmap_close
,
1471 .fault
= perf_mmap_fault
,
1474 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1476 struct perf_counter
*counter
= file
->private_data
;
1477 unsigned long vma_size
;
1478 unsigned long nr_pages
;
1479 unsigned long locked
, lock_limit
;
1482 if (!(vma
->vm_flags
& VM_SHARED
) || (vma
->vm_flags
& VM_WRITE
))
1485 vma_size
= vma
->vm_end
- vma
->vm_start
;
1486 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
1489 * If we have data pages ensure they're a power-of-two number, so we
1490 * can do bitmasks instead of modulo.
1492 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
1495 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
1498 if (vma
->vm_pgoff
!= 0)
1501 mutex_lock(&counter
->mmap_mutex
);
1502 if (atomic_inc_not_zero(&counter
->mmap_count
)) {
1503 if (nr_pages
!= counter
->data
->nr_pages
)
1508 locked
= vma
->vm_mm
->locked_vm
;
1509 locked
+= nr_pages
+ 1;
1511 lock_limit
= current
->signal
->rlim
[RLIMIT_MEMLOCK
].rlim_cur
;
1512 lock_limit
>>= PAGE_SHIFT
;
1514 if ((locked
> lock_limit
) && !capable(CAP_IPC_LOCK
)) {
1519 WARN_ON(counter
->data
);
1520 ret
= perf_mmap_data_alloc(counter
, nr_pages
);
1524 atomic_set(&counter
->mmap_count
, 1);
1525 vma
->vm_mm
->locked_vm
+= nr_pages
+ 1;
1527 mutex_unlock(&counter
->mmap_mutex
);
1529 vma
->vm_flags
&= ~VM_MAYWRITE
;
1530 vma
->vm_flags
|= VM_RESERVED
;
1531 vma
->vm_ops
= &perf_mmap_vmops
;
1536 static int perf_fasync(int fd
, struct file
*filp
, int on
)
1538 struct perf_counter
*counter
= filp
->private_data
;
1539 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
1542 mutex_lock(&inode
->i_mutex
);
1543 retval
= fasync_helper(fd
, filp
, on
, &counter
->fasync
);
1544 mutex_unlock(&inode
->i_mutex
);
1552 static const struct file_operations perf_fops
= {
1553 .release
= perf_release
,
1556 .unlocked_ioctl
= perf_ioctl
,
1557 .compat_ioctl
= perf_ioctl
,
1559 .fasync
= perf_fasync
,
1563 * Perf counter wakeup
1565 * If there's data, ensure we set the poll() state and publish everything
1566 * to user-space before waking everybody up.
1569 void perf_counter_wakeup(struct perf_counter
*counter
)
1571 struct perf_mmap_data
*data
;
1574 data
= rcu_dereference(counter
->data
);
1576 atomic_set(&data
->wakeup
, POLL_IN
);
1578 * Ensure all data writes are issued before updating the
1579 * user-space data head information. The matching rmb()
1580 * will be in userspace after reading this value.
1583 data
->user_page
->data_head
= atomic_read(&data
->head
);
1587 wake_up_all(&counter
->waitq
);
1589 if (counter
->pending_kill
) {
1590 kill_fasync(&counter
->fasync
, SIGIO
, counter
->pending_kill
);
1591 counter
->pending_kill
= 0;
1598 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
1600 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
1601 * single linked list and use cmpxchg() to add entries lockless.
1604 static void perf_pending_counter(struct perf_pending_entry
*entry
)
1606 struct perf_counter
*counter
= container_of(entry
,
1607 struct perf_counter
, pending
);
1609 if (counter
->pending_disable
) {
1610 counter
->pending_disable
= 0;
1611 perf_counter_disable(counter
);
1614 if (counter
->pending_wakeup
) {
1615 counter
->pending_wakeup
= 0;
1616 perf_counter_wakeup(counter
);
1620 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
1622 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
1626 static void perf_pending_queue(struct perf_pending_entry
*entry
,
1627 void (*func
)(struct perf_pending_entry
*))
1629 struct perf_pending_entry
**head
;
1631 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
1636 head
= &get_cpu_var(perf_pending_head
);
1639 entry
->next
= *head
;
1640 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
1642 set_perf_counter_pending();
1644 put_cpu_var(perf_pending_head
);
1647 static int __perf_pending_run(void)
1649 struct perf_pending_entry
*list
;
1652 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
1653 while (list
!= PENDING_TAIL
) {
1654 void (*func
)(struct perf_pending_entry
*);
1655 struct perf_pending_entry
*entry
= list
;
1662 * Ensure we observe the unqueue before we issue the wakeup,
1663 * so that we won't be waiting forever.
1664 * -- see perf_not_pending().
1675 static inline int perf_not_pending(struct perf_counter
*counter
)
1678 * If we flush on whatever cpu we run, there is a chance we don't
1682 __perf_pending_run();
1686 * Ensure we see the proper queue state before going to sleep
1687 * so that we do not miss the wakeup. -- see perf_pending_handle()
1690 return counter
->pending
.next
== NULL
;
1693 static void perf_pending_sync(struct perf_counter
*counter
)
1695 wait_event(counter
->waitq
, perf_not_pending(counter
));
1698 void perf_counter_do_pending(void)
1700 __perf_pending_run();
1704 * Callchain support -- arch specific
1707 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
1716 struct perf_output_handle
{
1717 struct perf_counter
*counter
;
1718 struct perf_mmap_data
*data
;
1719 unsigned int offset
;
1726 static inline void __perf_output_wakeup(struct perf_output_handle
*handle
)
1729 handle
->counter
->pending_wakeup
= 1;
1730 perf_pending_queue(&handle
->counter
->pending
,
1731 perf_pending_counter
);
1733 perf_counter_wakeup(handle
->counter
);
1736 static int perf_output_begin(struct perf_output_handle
*handle
,
1737 struct perf_counter
*counter
, unsigned int size
,
1738 int nmi
, int overflow
)
1740 struct perf_mmap_data
*data
;
1741 unsigned int offset
, head
;
1744 data
= rcu_dereference(counter
->data
);
1748 handle
->counter
= counter
;
1750 handle
->overflow
= overflow
;
1752 if (!data
->nr_pages
)
1756 offset
= head
= atomic_read(&data
->head
);
1758 } while (atomic_cmpxchg(&data
->head
, offset
, head
) != offset
);
1760 handle
->data
= data
;
1761 handle
->offset
= offset
;
1762 handle
->head
= head
;
1763 handle
->wakeup
= (offset
>> PAGE_SHIFT
) != (head
>> PAGE_SHIFT
);
1768 __perf_output_wakeup(handle
);
1775 static void perf_output_copy(struct perf_output_handle
*handle
,
1776 void *buf
, unsigned int len
)
1778 unsigned int pages_mask
;
1779 unsigned int offset
;
1783 offset
= handle
->offset
;
1784 pages_mask
= handle
->data
->nr_pages
- 1;
1785 pages
= handle
->data
->data_pages
;
1788 unsigned int page_offset
;
1791 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
1792 page_offset
= offset
& (PAGE_SIZE
- 1);
1793 size
= min_t(unsigned int, PAGE_SIZE
- page_offset
, len
);
1795 memcpy(pages
[nr
] + page_offset
, buf
, size
);
1802 handle
->offset
= offset
;
1804 WARN_ON_ONCE(handle
->offset
> handle
->head
);
1807 #define perf_output_put(handle, x) \
1808 perf_output_copy((handle), &(x), sizeof(x))
1810 static void perf_output_end(struct perf_output_handle
*handle
)
1812 int wakeup_events
= handle
->counter
->hw_event
.wakeup_events
;
1814 if (handle
->overflow
&& wakeup_events
) {
1815 int events
= atomic_inc_return(&handle
->data
->events
);
1816 if (events
>= wakeup_events
) {
1817 atomic_sub(wakeup_events
, &handle
->data
->events
);
1818 __perf_output_wakeup(handle
);
1820 } else if (handle
->wakeup
)
1821 __perf_output_wakeup(handle
);
1825 static void perf_counter_output(struct perf_counter
*counter
,
1826 int nmi
, struct pt_regs
*regs
, u64 addr
)
1829 u64 record_type
= counter
->hw_event
.record_type
;
1830 struct perf_output_handle handle
;
1831 struct perf_event_header header
;
1840 struct perf_callchain_entry
*callchain
= NULL
;
1841 int callchain_size
= 0;
1845 header
.size
= sizeof(header
);
1847 header
.misc
= PERF_EVENT_MISC_OVERFLOW
;
1848 header
.misc
|= user_mode(regs
) ?
1849 PERF_EVENT_MISC_USER
: PERF_EVENT_MISC_KERNEL
;
1851 if (record_type
& PERF_RECORD_IP
) {
1852 ip
= instruction_pointer(regs
);
1853 header
.type
|= PERF_RECORD_IP
;
1854 header
.size
+= sizeof(ip
);
1857 if (record_type
& PERF_RECORD_TID
) {
1858 /* namespace issues */
1859 tid_entry
.pid
= current
->group_leader
->pid
;
1860 tid_entry
.tid
= current
->pid
;
1862 header
.type
|= PERF_RECORD_TID
;
1863 header
.size
+= sizeof(tid_entry
);
1866 if (record_type
& PERF_RECORD_TIME
) {
1868 * Maybe do better on x86 and provide cpu_clock_nmi()
1870 time
= sched_clock();
1872 header
.type
|= PERF_RECORD_TIME
;
1873 header
.size
+= sizeof(u64
);
1876 if (record_type
& PERF_RECORD_ADDR
) {
1877 header
.type
|= PERF_RECORD_ADDR
;
1878 header
.size
+= sizeof(u64
);
1881 if (record_type
& PERF_RECORD_GROUP
) {
1882 header
.type
|= PERF_RECORD_GROUP
;
1883 header
.size
+= sizeof(u64
) +
1884 counter
->nr_siblings
* sizeof(group_entry
);
1887 if (record_type
& PERF_RECORD_CALLCHAIN
) {
1888 callchain
= perf_callchain(regs
);
1891 callchain_size
= (1 + callchain
->nr
) * sizeof(u64
);
1893 header
.type
|= PERF_RECORD_CALLCHAIN
;
1894 header
.size
+= callchain_size
;
1898 ret
= perf_output_begin(&handle
, counter
, header
.size
, nmi
, 1);
1902 perf_output_put(&handle
, header
);
1904 if (record_type
& PERF_RECORD_IP
)
1905 perf_output_put(&handle
, ip
);
1907 if (record_type
& PERF_RECORD_TID
)
1908 perf_output_put(&handle
, tid_entry
);
1910 if (record_type
& PERF_RECORD_TIME
)
1911 perf_output_put(&handle
, time
);
1913 if (record_type
& PERF_RECORD_ADDR
)
1914 perf_output_put(&handle
, addr
);
1916 if (record_type
& PERF_RECORD_GROUP
) {
1917 struct perf_counter
*leader
, *sub
;
1918 u64 nr
= counter
->nr_siblings
;
1920 perf_output_put(&handle
, nr
);
1922 leader
= counter
->group_leader
;
1923 list_for_each_entry(sub
, &leader
->sibling_list
, list_entry
) {
1925 sub
->hw_ops
->read(sub
);
1927 group_entry
.event
= sub
->hw_event
.config
;
1928 group_entry
.counter
= atomic64_read(&sub
->count
);
1930 perf_output_put(&handle
, group_entry
);
1935 perf_output_copy(&handle
, callchain
, callchain_size
);
1937 perf_output_end(&handle
);
1944 struct perf_comm_event
{
1945 struct task_struct
*task
;
1950 struct perf_event_header header
;
1957 static void perf_counter_comm_output(struct perf_counter
*counter
,
1958 struct perf_comm_event
*comm_event
)
1960 struct perf_output_handle handle
;
1961 int size
= comm_event
->event
.header
.size
;
1962 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
1967 perf_output_put(&handle
, comm_event
->event
);
1968 perf_output_copy(&handle
, comm_event
->comm
,
1969 comm_event
->comm_size
);
1970 perf_output_end(&handle
);
1973 static int perf_counter_comm_match(struct perf_counter
*counter
,
1974 struct perf_comm_event
*comm_event
)
1976 if (counter
->hw_event
.comm
&&
1977 comm_event
->event
.header
.type
== PERF_EVENT_COMM
)
1983 static void perf_counter_comm_ctx(struct perf_counter_context
*ctx
,
1984 struct perf_comm_event
*comm_event
)
1986 struct perf_counter
*counter
;
1988 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
1992 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
1993 if (perf_counter_comm_match(counter
, comm_event
))
1994 perf_counter_comm_output(counter
, comm_event
);
1999 static void perf_counter_comm_event(struct perf_comm_event
*comm_event
)
2001 struct perf_cpu_context
*cpuctx
;
2003 char *comm
= comm_event
->task
->comm
;
2005 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
2007 comm_event
->comm
= comm
;
2008 comm_event
->comm_size
= size
;
2010 comm_event
->event
.header
.size
= sizeof(comm_event
->event
) + size
;
2012 cpuctx
= &get_cpu_var(perf_cpu_context
);
2013 perf_counter_comm_ctx(&cpuctx
->ctx
, comm_event
);
2014 put_cpu_var(perf_cpu_context
);
2016 perf_counter_comm_ctx(¤t
->perf_counter_ctx
, comm_event
);
2019 void perf_counter_comm(struct task_struct
*task
)
2021 struct perf_comm_event comm_event
;
2023 if (!atomic_read(&nr_comm_tracking
))
2026 comm_event
= (struct perf_comm_event
){
2029 .header
= { .type
= PERF_EVENT_COMM
, },
2030 .pid
= task
->group_leader
->pid
,
2035 perf_counter_comm_event(&comm_event
);
2042 struct perf_mmap_event
{
2048 struct perf_event_header header
;
2058 static void perf_counter_mmap_output(struct perf_counter
*counter
,
2059 struct perf_mmap_event
*mmap_event
)
2061 struct perf_output_handle handle
;
2062 int size
= mmap_event
->event
.header
.size
;
2063 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
2068 perf_output_put(&handle
, mmap_event
->event
);
2069 perf_output_copy(&handle
, mmap_event
->file_name
,
2070 mmap_event
->file_size
);
2071 perf_output_end(&handle
);
2074 static int perf_counter_mmap_match(struct perf_counter
*counter
,
2075 struct perf_mmap_event
*mmap_event
)
2077 if (counter
->hw_event
.mmap
&&
2078 mmap_event
->event
.header
.type
== PERF_EVENT_MMAP
)
2081 if (counter
->hw_event
.munmap
&&
2082 mmap_event
->event
.header
.type
== PERF_EVENT_MUNMAP
)
2088 static void perf_counter_mmap_ctx(struct perf_counter_context
*ctx
,
2089 struct perf_mmap_event
*mmap_event
)
2091 struct perf_counter
*counter
;
2093 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2097 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2098 if (perf_counter_mmap_match(counter
, mmap_event
))
2099 perf_counter_mmap_output(counter
, mmap_event
);
2104 static void perf_counter_mmap_event(struct perf_mmap_event
*mmap_event
)
2106 struct perf_cpu_context
*cpuctx
;
2107 struct file
*file
= mmap_event
->file
;
2114 buf
= kzalloc(PATH_MAX
, GFP_KERNEL
);
2116 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
2119 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
2121 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
2125 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
2130 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
2132 mmap_event
->file_name
= name
;
2133 mmap_event
->file_size
= size
;
2135 mmap_event
->event
.header
.size
= sizeof(mmap_event
->event
) + size
;
2137 cpuctx
= &get_cpu_var(perf_cpu_context
);
2138 perf_counter_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
2139 put_cpu_var(perf_cpu_context
);
2141 perf_counter_mmap_ctx(¤t
->perf_counter_ctx
, mmap_event
);
2146 void perf_counter_mmap(unsigned long addr
, unsigned long len
,
2147 unsigned long pgoff
, struct file
*file
)
2149 struct perf_mmap_event mmap_event
;
2151 if (!atomic_read(&nr_mmap_tracking
))
2154 mmap_event
= (struct perf_mmap_event
){
2157 .header
= { .type
= PERF_EVENT_MMAP
, },
2158 .pid
= current
->group_leader
->pid
,
2159 .tid
= current
->pid
,
2166 perf_counter_mmap_event(&mmap_event
);
2169 void perf_counter_munmap(unsigned long addr
, unsigned long len
,
2170 unsigned long pgoff
, struct file
*file
)
2172 struct perf_mmap_event mmap_event
;
2174 if (!atomic_read(&nr_munmap_tracking
))
2177 mmap_event
= (struct perf_mmap_event
){
2180 .header
= { .type
= PERF_EVENT_MUNMAP
, },
2181 .pid
= current
->group_leader
->pid
,
2182 .tid
= current
->pid
,
2189 perf_counter_mmap_event(&mmap_event
);
2193 * Generic counter overflow handling.
2196 int perf_counter_overflow(struct perf_counter
*counter
,
2197 int nmi
, struct pt_regs
*regs
, u64 addr
)
2199 int events
= atomic_read(&counter
->event_limit
);
2202 counter
->pending_kill
= POLL_IN
;
2203 if (events
&& atomic_dec_and_test(&counter
->event_limit
)) {
2205 counter
->pending_kill
= POLL_HUP
;
2207 counter
->pending_disable
= 1;
2208 perf_pending_queue(&counter
->pending
,
2209 perf_pending_counter
);
2211 perf_counter_disable(counter
);
2214 perf_counter_output(counter
, nmi
, regs
, addr
);
2219 * Generic software counter infrastructure
2222 static void perf_swcounter_update(struct perf_counter
*counter
)
2224 struct hw_perf_counter
*hwc
= &counter
->hw
;
2229 prev
= atomic64_read(&hwc
->prev_count
);
2230 now
= atomic64_read(&hwc
->count
);
2231 if (atomic64_cmpxchg(&hwc
->prev_count
, prev
, now
) != prev
)
2236 atomic64_add(delta
, &counter
->count
);
2237 atomic64_sub(delta
, &hwc
->period_left
);
2240 static void perf_swcounter_set_period(struct perf_counter
*counter
)
2242 struct hw_perf_counter
*hwc
= &counter
->hw
;
2243 s64 left
= atomic64_read(&hwc
->period_left
);
2244 s64 period
= hwc
->irq_period
;
2246 if (unlikely(left
<= -period
)) {
2248 atomic64_set(&hwc
->period_left
, left
);
2251 if (unlikely(left
<= 0)) {
2253 atomic64_add(period
, &hwc
->period_left
);
2256 atomic64_set(&hwc
->prev_count
, -left
);
2257 atomic64_set(&hwc
->count
, -left
);
2260 static enum hrtimer_restart
perf_swcounter_hrtimer(struct hrtimer
*hrtimer
)
2262 enum hrtimer_restart ret
= HRTIMER_RESTART
;
2263 struct perf_counter
*counter
;
2264 struct pt_regs
*regs
;
2266 counter
= container_of(hrtimer
, struct perf_counter
, hw
.hrtimer
);
2267 counter
->hw_ops
->read(counter
);
2269 regs
= get_irq_regs();
2271 * In case we exclude kernel IPs or are somehow not in interrupt
2272 * context, provide the next best thing, the user IP.
2274 if ((counter
->hw_event
.exclude_kernel
|| !regs
) &&
2275 !counter
->hw_event
.exclude_user
)
2276 regs
= task_pt_regs(current
);
2279 if (perf_counter_overflow(counter
, 0, regs
, 0))
2280 ret
= HRTIMER_NORESTART
;
2283 hrtimer_forward_now(hrtimer
, ns_to_ktime(counter
->hw
.irq_period
));
2288 static void perf_swcounter_overflow(struct perf_counter
*counter
,
2289 int nmi
, struct pt_regs
*regs
, u64 addr
)
2291 perf_swcounter_update(counter
);
2292 perf_swcounter_set_period(counter
);
2293 if (perf_counter_overflow(counter
, nmi
, regs
, addr
))
2294 /* soft-disable the counter */
2299 static int perf_swcounter_match(struct perf_counter
*counter
,
2300 enum perf_event_types type
,
2301 u32 event
, struct pt_regs
*regs
)
2303 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
2306 if (perf_event_raw(&counter
->hw_event
))
2309 if (perf_event_type(&counter
->hw_event
) != type
)
2312 if (perf_event_id(&counter
->hw_event
) != event
)
2315 if (counter
->hw_event
.exclude_user
&& user_mode(regs
))
2318 if (counter
->hw_event
.exclude_kernel
&& !user_mode(regs
))
2324 static void perf_swcounter_add(struct perf_counter
*counter
, u64 nr
,
2325 int nmi
, struct pt_regs
*regs
, u64 addr
)
2327 int neg
= atomic64_add_negative(nr
, &counter
->hw
.count
);
2328 if (counter
->hw
.irq_period
&& !neg
)
2329 perf_swcounter_overflow(counter
, nmi
, regs
, addr
);
2332 static void perf_swcounter_ctx_event(struct perf_counter_context
*ctx
,
2333 enum perf_event_types type
, u32 event
,
2334 u64 nr
, int nmi
, struct pt_regs
*regs
,
2337 struct perf_counter
*counter
;
2339 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2343 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2344 if (perf_swcounter_match(counter
, type
, event
, regs
))
2345 perf_swcounter_add(counter
, nr
, nmi
, regs
, addr
);
2350 static int *perf_swcounter_recursion_context(struct perf_cpu_context
*cpuctx
)
2353 return &cpuctx
->recursion
[3];
2356 return &cpuctx
->recursion
[2];
2359 return &cpuctx
->recursion
[1];
2361 return &cpuctx
->recursion
[0];
2364 static void __perf_swcounter_event(enum perf_event_types type
, u32 event
,
2365 u64 nr
, int nmi
, struct pt_regs
*regs
,
2368 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
2369 int *recursion
= perf_swcounter_recursion_context(cpuctx
);
2377 perf_swcounter_ctx_event(&cpuctx
->ctx
, type
, event
,
2378 nr
, nmi
, regs
, addr
);
2379 if (cpuctx
->task_ctx
) {
2380 perf_swcounter_ctx_event(cpuctx
->task_ctx
, type
, event
,
2381 nr
, nmi
, regs
, addr
);
2388 put_cpu_var(perf_cpu_context
);
2392 perf_swcounter_event(u32 event
, u64 nr
, int nmi
, struct pt_regs
*regs
, u64 addr
)
2394 __perf_swcounter_event(PERF_TYPE_SOFTWARE
, event
, nr
, nmi
, regs
, addr
);
2397 static void perf_swcounter_read(struct perf_counter
*counter
)
2399 perf_swcounter_update(counter
);
2402 static int perf_swcounter_enable(struct perf_counter
*counter
)
2404 perf_swcounter_set_period(counter
);
2408 static void perf_swcounter_disable(struct perf_counter
*counter
)
2410 perf_swcounter_update(counter
);
2413 static const struct hw_perf_counter_ops perf_ops_generic
= {
2414 .enable
= perf_swcounter_enable
,
2415 .disable
= perf_swcounter_disable
,
2416 .read
= perf_swcounter_read
,
2420 * Software counter: cpu wall time clock
2423 static void cpu_clock_perf_counter_update(struct perf_counter
*counter
)
2425 int cpu
= raw_smp_processor_id();
2429 now
= cpu_clock(cpu
);
2430 prev
= atomic64_read(&counter
->hw
.prev_count
);
2431 atomic64_set(&counter
->hw
.prev_count
, now
);
2432 atomic64_add(now
- prev
, &counter
->count
);
2435 static int cpu_clock_perf_counter_enable(struct perf_counter
*counter
)
2437 struct hw_perf_counter
*hwc
= &counter
->hw
;
2438 int cpu
= raw_smp_processor_id();
2440 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
2441 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2442 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2443 if (hwc
->irq_period
) {
2444 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2445 ns_to_ktime(hwc
->irq_period
), 0,
2446 HRTIMER_MODE_REL
, 0);
2452 static void cpu_clock_perf_counter_disable(struct perf_counter
*counter
)
2454 hrtimer_cancel(&counter
->hw
.hrtimer
);
2455 cpu_clock_perf_counter_update(counter
);
2458 static void cpu_clock_perf_counter_read(struct perf_counter
*counter
)
2460 cpu_clock_perf_counter_update(counter
);
2463 static const struct hw_perf_counter_ops perf_ops_cpu_clock
= {
2464 .enable
= cpu_clock_perf_counter_enable
,
2465 .disable
= cpu_clock_perf_counter_disable
,
2466 .read
= cpu_clock_perf_counter_read
,
2470 * Software counter: task time clock
2473 static void task_clock_perf_counter_update(struct perf_counter
*counter
, u64 now
)
2478 prev
= atomic64_xchg(&counter
->hw
.prev_count
, now
);
2480 atomic64_add(delta
, &counter
->count
);
2483 static int task_clock_perf_counter_enable(struct perf_counter
*counter
)
2485 struct hw_perf_counter
*hwc
= &counter
->hw
;
2488 now
= counter
->ctx
->time
;
2490 atomic64_set(&hwc
->prev_count
, now
);
2491 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2492 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2493 if (hwc
->irq_period
) {
2494 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2495 ns_to_ktime(hwc
->irq_period
), 0,
2496 HRTIMER_MODE_REL
, 0);
2502 static void task_clock_perf_counter_disable(struct perf_counter
*counter
)
2504 hrtimer_cancel(&counter
->hw
.hrtimer
);
2505 task_clock_perf_counter_update(counter
, counter
->ctx
->time
);
2509 static void task_clock_perf_counter_read(struct perf_counter
*counter
)
2514 update_context_time(counter
->ctx
);
2515 time
= counter
->ctx
->time
;
2517 u64 now
= perf_clock();
2518 u64 delta
= now
- counter
->ctx
->timestamp
;
2519 time
= counter
->ctx
->time
+ delta
;
2522 task_clock_perf_counter_update(counter
, time
);
2525 static const struct hw_perf_counter_ops perf_ops_task_clock
= {
2526 .enable
= task_clock_perf_counter_enable
,
2527 .disable
= task_clock_perf_counter_disable
,
2528 .read
= task_clock_perf_counter_read
,
2532 * Software counter: cpu migrations
2535 static inline u64
get_cpu_migrations(struct perf_counter
*counter
)
2537 struct task_struct
*curr
= counter
->ctx
->task
;
2540 return curr
->se
.nr_migrations
;
2541 return cpu_nr_migrations(smp_processor_id());
2544 static void cpu_migrations_perf_counter_update(struct perf_counter
*counter
)
2549 prev
= atomic64_read(&counter
->hw
.prev_count
);
2550 now
= get_cpu_migrations(counter
);
2552 atomic64_set(&counter
->hw
.prev_count
, now
);
2556 atomic64_add(delta
, &counter
->count
);
2559 static void cpu_migrations_perf_counter_read(struct perf_counter
*counter
)
2561 cpu_migrations_perf_counter_update(counter
);
2564 static int cpu_migrations_perf_counter_enable(struct perf_counter
*counter
)
2566 if (counter
->prev_state
<= PERF_COUNTER_STATE_OFF
)
2567 atomic64_set(&counter
->hw
.prev_count
,
2568 get_cpu_migrations(counter
));
2572 static void cpu_migrations_perf_counter_disable(struct perf_counter
*counter
)
2574 cpu_migrations_perf_counter_update(counter
);
2577 static const struct hw_perf_counter_ops perf_ops_cpu_migrations
= {
2578 .enable
= cpu_migrations_perf_counter_enable
,
2579 .disable
= cpu_migrations_perf_counter_disable
,
2580 .read
= cpu_migrations_perf_counter_read
,
2583 #ifdef CONFIG_EVENT_PROFILE
2584 void perf_tpcounter_event(int event_id
)
2586 struct pt_regs
*regs
= get_irq_regs();
2589 regs
= task_pt_regs(current
);
2591 __perf_swcounter_event(PERF_TYPE_TRACEPOINT
, event_id
, 1, 1, regs
, 0);
2594 extern int ftrace_profile_enable(int);
2595 extern void ftrace_profile_disable(int);
2597 static void tp_perf_counter_destroy(struct perf_counter
*counter
)
2599 ftrace_profile_disable(perf_event_id(&counter
->hw_event
));
2602 static const struct hw_perf_counter_ops
*
2603 tp_perf_counter_init(struct perf_counter
*counter
)
2605 int event_id
= perf_event_id(&counter
->hw_event
);
2608 ret
= ftrace_profile_enable(event_id
);
2612 counter
->destroy
= tp_perf_counter_destroy
;
2613 counter
->hw
.irq_period
= counter
->hw_event
.irq_period
;
2615 return &perf_ops_generic
;
2618 static const struct hw_perf_counter_ops
*
2619 tp_perf_counter_init(struct perf_counter
*counter
)
2625 static const struct hw_perf_counter_ops
*
2626 sw_perf_counter_init(struct perf_counter
*counter
)
2628 struct perf_counter_hw_event
*hw_event
= &counter
->hw_event
;
2629 const struct hw_perf_counter_ops
*hw_ops
= NULL
;
2630 struct hw_perf_counter
*hwc
= &counter
->hw
;
2633 * Software counters (currently) can't in general distinguish
2634 * between user, kernel and hypervisor events.
2635 * However, context switches and cpu migrations are considered
2636 * to be kernel events, and page faults are never hypervisor
2639 switch (perf_event_id(&counter
->hw_event
)) {
2640 case PERF_COUNT_CPU_CLOCK
:
2641 hw_ops
= &perf_ops_cpu_clock
;
2643 if (hw_event
->irq_period
&& hw_event
->irq_period
< 10000)
2644 hw_event
->irq_period
= 10000;
2646 case PERF_COUNT_TASK_CLOCK
:
2648 * If the user instantiates this as a per-cpu counter,
2649 * use the cpu_clock counter instead.
2651 if (counter
->ctx
->task
)
2652 hw_ops
= &perf_ops_task_clock
;
2654 hw_ops
= &perf_ops_cpu_clock
;
2656 if (hw_event
->irq_period
&& hw_event
->irq_period
< 10000)
2657 hw_event
->irq_period
= 10000;
2659 case PERF_COUNT_PAGE_FAULTS
:
2660 case PERF_COUNT_PAGE_FAULTS_MIN
:
2661 case PERF_COUNT_PAGE_FAULTS_MAJ
:
2662 case PERF_COUNT_CONTEXT_SWITCHES
:
2663 hw_ops
= &perf_ops_generic
;
2665 case PERF_COUNT_CPU_MIGRATIONS
:
2666 if (!counter
->hw_event
.exclude_kernel
)
2667 hw_ops
= &perf_ops_cpu_migrations
;
2672 hwc
->irq_period
= hw_event
->irq_period
;
2678 * Allocate and initialize a counter structure
2680 static struct perf_counter
*
2681 perf_counter_alloc(struct perf_counter_hw_event
*hw_event
,
2683 struct perf_counter_context
*ctx
,
2684 struct perf_counter
*group_leader
,
2687 const struct hw_perf_counter_ops
*hw_ops
;
2688 struct perf_counter
*counter
;
2691 counter
= kzalloc(sizeof(*counter
), gfpflags
);
2693 return ERR_PTR(-ENOMEM
);
2696 * Single counters are their own group leaders, with an
2697 * empty sibling list:
2700 group_leader
= counter
;
2702 mutex_init(&counter
->mutex
);
2703 INIT_LIST_HEAD(&counter
->list_entry
);
2704 INIT_LIST_HEAD(&counter
->event_entry
);
2705 INIT_LIST_HEAD(&counter
->sibling_list
);
2706 init_waitqueue_head(&counter
->waitq
);
2708 mutex_init(&counter
->mmap_mutex
);
2710 INIT_LIST_HEAD(&counter
->child_list
);
2713 counter
->hw_event
= *hw_event
;
2714 counter
->group_leader
= group_leader
;
2715 counter
->hw_ops
= NULL
;
2718 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
2719 if (hw_event
->disabled
)
2720 counter
->state
= PERF_COUNTER_STATE_OFF
;
2724 if (perf_event_raw(hw_event
)) {
2725 hw_ops
= hw_perf_counter_init(counter
);
2729 switch (perf_event_type(hw_event
)) {
2730 case PERF_TYPE_HARDWARE
:
2731 hw_ops
= hw_perf_counter_init(counter
);
2734 case PERF_TYPE_SOFTWARE
:
2735 hw_ops
= sw_perf_counter_init(counter
);
2738 case PERF_TYPE_TRACEPOINT
:
2739 hw_ops
= tp_perf_counter_init(counter
);
2746 else if (IS_ERR(hw_ops
))
2747 err
= PTR_ERR(hw_ops
);
2751 return ERR_PTR(err
);
2754 counter
->hw_ops
= hw_ops
;
2756 if (counter
->hw_event
.mmap
)
2757 atomic_inc(&nr_mmap_tracking
);
2758 if (counter
->hw_event
.munmap
)
2759 atomic_inc(&nr_munmap_tracking
);
2760 if (counter
->hw_event
.comm
)
2761 atomic_inc(&nr_comm_tracking
);
2767 * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
2769 * @hw_event_uptr: event type attributes for monitoring/sampling
2772 * @group_fd: group leader counter fd
2774 SYSCALL_DEFINE5(perf_counter_open
,
2775 const struct perf_counter_hw_event __user
*, hw_event_uptr
,
2776 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
2778 struct perf_counter
*counter
, *group_leader
;
2779 struct perf_counter_hw_event hw_event
;
2780 struct perf_counter_context
*ctx
;
2781 struct file
*counter_file
= NULL
;
2782 struct file
*group_file
= NULL
;
2783 int fput_needed
= 0;
2784 int fput_needed2
= 0;
2787 /* for future expandability... */
2791 if (copy_from_user(&hw_event
, hw_event_uptr
, sizeof(hw_event
)) != 0)
2795 * Get the target context (task or percpu):
2797 ctx
= find_get_context(pid
, cpu
);
2799 return PTR_ERR(ctx
);
2802 * Look up the group leader (we will attach this counter to it):
2804 group_leader
= NULL
;
2805 if (group_fd
!= -1) {
2807 group_file
= fget_light(group_fd
, &fput_needed
);
2809 goto err_put_context
;
2810 if (group_file
->f_op
!= &perf_fops
)
2811 goto err_put_context
;
2813 group_leader
= group_file
->private_data
;
2815 * Do not allow a recursive hierarchy (this new sibling
2816 * becoming part of another group-sibling):
2818 if (group_leader
->group_leader
!= group_leader
)
2819 goto err_put_context
;
2821 * Do not allow to attach to a group in a different
2822 * task or CPU context:
2824 if (group_leader
->ctx
!= ctx
)
2825 goto err_put_context
;
2827 * Only a group leader can be exclusive or pinned
2829 if (hw_event
.exclusive
|| hw_event
.pinned
)
2830 goto err_put_context
;
2833 counter
= perf_counter_alloc(&hw_event
, cpu
, ctx
, group_leader
,
2835 ret
= PTR_ERR(counter
);
2836 if (IS_ERR(counter
))
2837 goto err_put_context
;
2839 ret
= anon_inode_getfd("[perf_counter]", &perf_fops
, counter
, 0);
2841 goto err_free_put_context
;
2843 counter_file
= fget_light(ret
, &fput_needed2
);
2845 goto err_free_put_context
;
2847 counter
->filp
= counter_file
;
2848 mutex_lock(&ctx
->mutex
);
2849 perf_install_in_context(ctx
, counter
, cpu
);
2850 mutex_unlock(&ctx
->mutex
);
2852 fput_light(counter_file
, fput_needed2
);
2855 fput_light(group_file
, fput_needed
);
2859 err_free_put_context
:
2869 * Initialize the perf_counter context in a task_struct:
2872 __perf_counter_init_context(struct perf_counter_context
*ctx
,
2873 struct task_struct
*task
)
2875 memset(ctx
, 0, sizeof(*ctx
));
2876 spin_lock_init(&ctx
->lock
);
2877 mutex_init(&ctx
->mutex
);
2878 INIT_LIST_HEAD(&ctx
->counter_list
);
2879 INIT_LIST_HEAD(&ctx
->event_list
);
2884 * inherit a counter from parent task to child task:
2886 static struct perf_counter
*
2887 inherit_counter(struct perf_counter
*parent_counter
,
2888 struct task_struct
*parent
,
2889 struct perf_counter_context
*parent_ctx
,
2890 struct task_struct
*child
,
2891 struct perf_counter
*group_leader
,
2892 struct perf_counter_context
*child_ctx
)
2894 struct perf_counter
*child_counter
;
2897 * Instead of creating recursive hierarchies of counters,
2898 * we link inherited counters back to the original parent,
2899 * which has a filp for sure, which we use as the reference
2902 if (parent_counter
->parent
)
2903 parent_counter
= parent_counter
->parent
;
2905 child_counter
= perf_counter_alloc(&parent_counter
->hw_event
,
2906 parent_counter
->cpu
, child_ctx
,
2907 group_leader
, GFP_KERNEL
);
2908 if (IS_ERR(child_counter
))
2909 return child_counter
;
2912 * Link it up in the child's context:
2914 child_counter
->task
= child
;
2915 add_counter_to_ctx(child_counter
, child_ctx
);
2917 child_counter
->parent
= parent_counter
;
2919 * inherit into child's child as well:
2921 child_counter
->hw_event
.inherit
= 1;
2924 * Get a reference to the parent filp - we will fput it
2925 * when the child counter exits. This is safe to do because
2926 * we are in the parent and we know that the filp still
2927 * exists and has a nonzero count:
2929 atomic_long_inc(&parent_counter
->filp
->f_count
);
2932 * Link this into the parent counter's child list
2934 mutex_lock(&parent_counter
->mutex
);
2935 list_add_tail(&child_counter
->child_list
, &parent_counter
->child_list
);
2938 * Make the child state follow the state of the parent counter,
2939 * not its hw_event.disabled bit. We hold the parent's mutex,
2940 * so we won't race with perf_counter_{en,dis}able_family.
2942 if (parent_counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
2943 child_counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
2945 child_counter
->state
= PERF_COUNTER_STATE_OFF
;
2947 mutex_unlock(&parent_counter
->mutex
);
2949 return child_counter
;
2952 static int inherit_group(struct perf_counter
*parent_counter
,
2953 struct task_struct
*parent
,
2954 struct perf_counter_context
*parent_ctx
,
2955 struct task_struct
*child
,
2956 struct perf_counter_context
*child_ctx
)
2958 struct perf_counter
*leader
;
2959 struct perf_counter
*sub
;
2960 struct perf_counter
*child_ctr
;
2962 leader
= inherit_counter(parent_counter
, parent
, parent_ctx
,
2963 child
, NULL
, child_ctx
);
2965 return PTR_ERR(leader
);
2966 list_for_each_entry(sub
, &parent_counter
->sibling_list
, list_entry
) {
2967 child_ctr
= inherit_counter(sub
, parent
, parent_ctx
,
2968 child
, leader
, child_ctx
);
2969 if (IS_ERR(child_ctr
))
2970 return PTR_ERR(child_ctr
);
2975 static void sync_child_counter(struct perf_counter
*child_counter
,
2976 struct perf_counter
*parent_counter
)
2978 u64 parent_val
, child_val
;
2980 parent_val
= atomic64_read(&parent_counter
->count
);
2981 child_val
= atomic64_read(&child_counter
->count
);
2984 * Add back the child's count to the parent's count:
2986 atomic64_add(child_val
, &parent_counter
->count
);
2987 atomic64_add(child_counter
->total_time_enabled
,
2988 &parent_counter
->child_total_time_enabled
);
2989 atomic64_add(child_counter
->total_time_running
,
2990 &parent_counter
->child_total_time_running
);
2993 * Remove this counter from the parent's list
2995 mutex_lock(&parent_counter
->mutex
);
2996 list_del_init(&child_counter
->child_list
);
2997 mutex_unlock(&parent_counter
->mutex
);
3000 * Release the parent counter, if this was the last
3003 fput(parent_counter
->filp
);
3007 __perf_counter_exit_task(struct task_struct
*child
,
3008 struct perf_counter
*child_counter
,
3009 struct perf_counter_context
*child_ctx
)
3011 struct perf_counter
*parent_counter
;
3012 struct perf_counter
*sub
, *tmp
;
3015 * If we do not self-reap then we have to wait for the
3016 * child task to unschedule (it will happen for sure),
3017 * so that its counter is at its final count. (This
3018 * condition triggers rarely - child tasks usually get
3019 * off their CPU before the parent has a chance to
3020 * get this far into the reaping action)
3022 if (child
!= current
) {
3023 wait_task_inactive(child
, 0);
3024 list_del_init(&child_counter
->list_entry
);
3025 update_counter_times(child_counter
);
3027 struct perf_cpu_context
*cpuctx
;
3028 unsigned long flags
;
3032 * Disable and unlink this counter.
3034 * Be careful about zapping the list - IRQ/NMI context
3035 * could still be processing it:
3037 local_irq_save(flags
);
3038 perf_flags
= hw_perf_save_disable();
3040 cpuctx
= &__get_cpu_var(perf_cpu_context
);
3042 group_sched_out(child_counter
, cpuctx
, child_ctx
);
3043 update_counter_times(child_counter
);
3045 list_del_init(&child_counter
->list_entry
);
3047 child_ctx
->nr_counters
--;
3049 hw_perf_restore(perf_flags
);
3050 local_irq_restore(flags
);
3053 parent_counter
= child_counter
->parent
;
3055 * It can happen that parent exits first, and has counters
3056 * that are still around due to the child reference. These
3057 * counters need to be zapped - but otherwise linger.
3059 if (parent_counter
) {
3060 sync_child_counter(child_counter
, parent_counter
);
3061 list_for_each_entry_safe(sub
, tmp
, &child_counter
->sibling_list
,
3064 sync_child_counter(sub
, sub
->parent
);
3068 free_counter(child_counter
);
3073 * When a child task exits, feed back counter values to parent counters.
3075 * Note: we may be running in child context, but the PID is not hashed
3076 * anymore so new counters will not be added.
3078 void perf_counter_exit_task(struct task_struct
*child
)
3080 struct perf_counter
*child_counter
, *tmp
;
3081 struct perf_counter_context
*child_ctx
;
3083 child_ctx
= &child
->perf_counter_ctx
;
3085 if (likely(!child_ctx
->nr_counters
))
3088 list_for_each_entry_safe(child_counter
, tmp
, &child_ctx
->counter_list
,
3090 __perf_counter_exit_task(child
, child_counter
, child_ctx
);
3094 * Initialize the perf_counter context in task_struct
3096 void perf_counter_init_task(struct task_struct
*child
)
3098 struct perf_counter_context
*child_ctx
, *parent_ctx
;
3099 struct perf_counter
*counter
;
3100 struct task_struct
*parent
= current
;
3102 child_ctx
= &child
->perf_counter_ctx
;
3103 parent_ctx
= &parent
->perf_counter_ctx
;
3105 __perf_counter_init_context(child_ctx
, child
);
3108 * This is executed from the parent task context, so inherit
3109 * counters that have been marked for cloning:
3112 if (likely(!parent_ctx
->nr_counters
))
3116 * Lock the parent list. No need to lock the child - not PID
3117 * hashed yet and not running, so nobody can access it.
3119 mutex_lock(&parent_ctx
->mutex
);
3122 * We dont have to disable NMIs - we are only looking at
3123 * the list, not manipulating it:
3125 list_for_each_entry(counter
, &parent_ctx
->counter_list
, list_entry
) {
3126 if (!counter
->hw_event
.inherit
)
3129 if (inherit_group(counter
, parent
,
3130 parent_ctx
, child
, child_ctx
))
3134 mutex_unlock(&parent_ctx
->mutex
);
3137 static void __cpuinit
perf_counter_init_cpu(int cpu
)
3139 struct perf_cpu_context
*cpuctx
;
3141 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3142 __perf_counter_init_context(&cpuctx
->ctx
, NULL
);
3144 mutex_lock(&perf_resource_mutex
);
3145 cpuctx
->max_pertask
= perf_max_counters
- perf_reserved_percpu
;
3146 mutex_unlock(&perf_resource_mutex
);
3148 hw_perf_counter_setup(cpu
);
3151 #ifdef CONFIG_HOTPLUG_CPU
3152 static void __perf_counter_exit_cpu(void *info
)
3154 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
3155 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3156 struct perf_counter
*counter
, *tmp
;
3158 list_for_each_entry_safe(counter
, tmp
, &ctx
->counter_list
, list_entry
)
3159 __perf_counter_remove_from_context(counter
);
3161 static void perf_counter_exit_cpu(int cpu
)
3163 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3164 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3166 mutex_lock(&ctx
->mutex
);
3167 smp_call_function_single(cpu
, __perf_counter_exit_cpu
, NULL
, 1);
3168 mutex_unlock(&ctx
->mutex
);
3171 static inline void perf_counter_exit_cpu(int cpu
) { }
3174 static int __cpuinit
3175 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
3177 unsigned int cpu
= (long)hcpu
;
3181 case CPU_UP_PREPARE
:
3182 case CPU_UP_PREPARE_FROZEN
:
3183 perf_counter_init_cpu(cpu
);
3186 case CPU_DOWN_PREPARE
:
3187 case CPU_DOWN_PREPARE_FROZEN
:
3188 perf_counter_exit_cpu(cpu
);
3198 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
3199 .notifier_call
= perf_cpu_notify
,
3202 static int __init
perf_counter_init(void)
3204 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
3205 (void *)(long)smp_processor_id());
3206 register_cpu_notifier(&perf_cpu_nb
);
3210 early_initcall(perf_counter_init
);
3212 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class, char *buf
)
3214 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
3218 perf_set_reserve_percpu(struct sysdev_class
*class,
3222 struct perf_cpu_context
*cpuctx
;
3226 err
= strict_strtoul(buf
, 10, &val
);
3229 if (val
> perf_max_counters
)
3232 mutex_lock(&perf_resource_mutex
);
3233 perf_reserved_percpu
= val
;
3234 for_each_online_cpu(cpu
) {
3235 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3236 spin_lock_irq(&cpuctx
->ctx
.lock
);
3237 mpt
= min(perf_max_counters
- cpuctx
->ctx
.nr_counters
,
3238 perf_max_counters
- perf_reserved_percpu
);
3239 cpuctx
->max_pertask
= mpt
;
3240 spin_unlock_irq(&cpuctx
->ctx
.lock
);
3242 mutex_unlock(&perf_resource_mutex
);
3247 static ssize_t
perf_show_overcommit(struct sysdev_class
*class, char *buf
)
3249 return sprintf(buf
, "%d\n", perf_overcommit
);
3253 perf_set_overcommit(struct sysdev_class
*class, const char *buf
, size_t count
)
3258 err
= strict_strtoul(buf
, 10, &val
);
3264 mutex_lock(&perf_resource_mutex
);
3265 perf_overcommit
= val
;
3266 mutex_unlock(&perf_resource_mutex
);
3271 static SYSDEV_CLASS_ATTR(
3274 perf_show_reserve_percpu
,
3275 perf_set_reserve_percpu
3278 static SYSDEV_CLASS_ATTR(
3281 perf_show_overcommit
,
3285 static struct attribute
*perfclass_attrs
[] = {
3286 &attr_reserve_percpu
.attr
,
3287 &attr_overcommit
.attr
,
3291 static struct attribute_group perfclass_attr_group
= {
3292 .attrs
= perfclass_attrs
,
3293 .name
= "perf_counters",
3296 static int __init
perf_counter_sysfs_init(void)
3298 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
3299 &perfclass_attr_group
);
3301 device_initcall(perf_counter_sysfs_init
);