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 pmu
*hw_perf_counter_init(struct perf_counter
*counter
)
60 u64 __weak
hw_perf_save_disable(void) { return 0; }
61 void __weak
hw_perf_restore(u64 ctrl
) { barrier(); }
62 void __weak
hw_perf_counter_setup(int cpu
) { barrier(); }
63 int __weak
hw_perf_group_sched_in(struct perf_counter
*group_leader
,
64 struct perf_cpu_context
*cpuctx
,
65 struct perf_counter_context
*ctx
, int cpu
)
70 void __weak
perf_counter_print_debug(void) { }
73 list_add_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
75 struct perf_counter
*group_leader
= counter
->group_leader
;
78 * Depending on whether it is a standalone or sibling counter,
79 * add it straight to the context's counter list, or to the group
80 * leader's sibling list:
82 if (counter
->group_leader
== counter
)
83 list_add_tail(&counter
->list_entry
, &ctx
->counter_list
);
85 list_add_tail(&counter
->list_entry
, &group_leader
->sibling_list
);
86 group_leader
->nr_siblings
++;
89 list_add_rcu(&counter
->event_entry
, &ctx
->event_list
);
93 list_del_counter(struct perf_counter
*counter
, struct perf_counter_context
*ctx
)
95 struct perf_counter
*sibling
, *tmp
;
97 list_del_init(&counter
->list_entry
);
98 list_del_rcu(&counter
->event_entry
);
100 if (counter
->group_leader
!= counter
)
101 counter
->group_leader
->nr_siblings
--;
104 * If this was a group counter with sibling counters then
105 * upgrade the siblings to singleton counters by adding them
106 * to the context list directly:
108 list_for_each_entry_safe(sibling
, tmp
,
109 &counter
->sibling_list
, list_entry
) {
111 list_move_tail(&sibling
->list_entry
, &ctx
->counter_list
);
112 sibling
->group_leader
= sibling
;
117 counter_sched_out(struct perf_counter
*counter
,
118 struct perf_cpu_context
*cpuctx
,
119 struct perf_counter_context
*ctx
)
121 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
124 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
125 counter
->tstamp_stopped
= ctx
->time
;
126 counter
->pmu
->disable(counter
);
129 if (!is_software_counter(counter
))
130 cpuctx
->active_oncpu
--;
132 if (counter
->hw_event
.exclusive
|| !cpuctx
->active_oncpu
)
133 cpuctx
->exclusive
= 0;
137 group_sched_out(struct perf_counter
*group_counter
,
138 struct perf_cpu_context
*cpuctx
,
139 struct perf_counter_context
*ctx
)
141 struct perf_counter
*counter
;
143 if (group_counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
146 counter_sched_out(group_counter
, cpuctx
, ctx
);
149 * Schedule out siblings (if any):
151 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
)
152 counter_sched_out(counter
, cpuctx
, ctx
);
154 if (group_counter
->hw_event
.exclusive
)
155 cpuctx
->exclusive
= 0;
159 * Cross CPU call to remove a performance counter
161 * We disable the counter on the hardware level first. After that we
162 * remove it from the context list.
164 static void __perf_counter_remove_from_context(void *info
)
166 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
167 struct perf_counter
*counter
= info
;
168 struct perf_counter_context
*ctx
= counter
->ctx
;
173 * If this is a task context, we need to check whether it is
174 * the current task context of this cpu. If not it has been
175 * scheduled out before the smp call arrived.
177 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
180 spin_lock_irqsave(&ctx
->lock
, flags
);
182 counter_sched_out(counter
, cpuctx
, ctx
);
184 counter
->task
= NULL
;
188 * Protect the list operation against NMI by disabling the
189 * counters on a global level. NOP for non NMI based counters.
191 perf_flags
= hw_perf_save_disable();
192 list_del_counter(counter
, ctx
);
193 hw_perf_restore(perf_flags
);
197 * Allow more per task counters with respect to the
200 cpuctx
->max_pertask
=
201 min(perf_max_counters
- ctx
->nr_counters
,
202 perf_max_counters
- perf_reserved_percpu
);
205 spin_unlock_irqrestore(&ctx
->lock
, flags
);
210 * Remove the counter from a task's (or a CPU's) list of counters.
212 * Must be called with counter->mutex and ctx->mutex held.
214 * CPU counters are removed with a smp call. For task counters we only
215 * call when the task is on a CPU.
217 static void perf_counter_remove_from_context(struct perf_counter
*counter
)
219 struct perf_counter_context
*ctx
= counter
->ctx
;
220 struct task_struct
*task
= ctx
->task
;
224 * Per cpu counters are removed via an smp call and
225 * the removal is always sucessful.
227 smp_call_function_single(counter
->cpu
,
228 __perf_counter_remove_from_context
,
234 task_oncpu_function_call(task
, __perf_counter_remove_from_context
,
237 spin_lock_irq(&ctx
->lock
);
239 * If the context is active we need to retry the smp call.
241 if (ctx
->nr_active
&& !list_empty(&counter
->list_entry
)) {
242 spin_unlock_irq(&ctx
->lock
);
247 * The lock prevents that this context is scheduled in so we
248 * can remove the counter safely, if the call above did not
251 if (!list_empty(&counter
->list_entry
)) {
253 list_del_counter(counter
, ctx
);
254 counter
->task
= NULL
;
256 spin_unlock_irq(&ctx
->lock
);
259 static inline u64
perf_clock(void)
261 return cpu_clock(smp_processor_id());
265 * Update the record of the current time in a context.
267 static void update_context_time(struct perf_counter_context
*ctx
)
269 u64 now
= perf_clock();
271 ctx
->time
+= now
- ctx
->timestamp
;
272 ctx
->timestamp
= now
;
276 * Update the total_time_enabled and total_time_running fields for a counter.
278 static void update_counter_times(struct perf_counter
*counter
)
280 struct perf_counter_context
*ctx
= counter
->ctx
;
283 if (counter
->state
< PERF_COUNTER_STATE_INACTIVE
)
286 counter
->total_time_enabled
= ctx
->time
- counter
->tstamp_enabled
;
288 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
)
289 run_end
= counter
->tstamp_stopped
;
293 counter
->total_time_running
= run_end
- counter
->tstamp_running
;
297 * Update total_time_enabled and total_time_running for all counters in a group.
299 static void update_group_times(struct perf_counter
*leader
)
301 struct perf_counter
*counter
;
303 update_counter_times(leader
);
304 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
305 update_counter_times(counter
);
309 * Cross CPU call to disable a performance counter
311 static void __perf_counter_disable(void *info
)
313 struct perf_counter
*counter
= info
;
314 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
315 struct perf_counter_context
*ctx
= counter
->ctx
;
319 * If this is a per-task counter, need to check whether this
320 * counter's task is the current task on this cpu.
322 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
325 spin_lock_irqsave(&ctx
->lock
, flags
);
328 * If the counter is on, turn it off.
329 * If it is in error state, leave it in error state.
331 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
) {
332 update_context_time(ctx
);
333 update_counter_times(counter
);
334 if (counter
== counter
->group_leader
)
335 group_sched_out(counter
, cpuctx
, ctx
);
337 counter_sched_out(counter
, cpuctx
, ctx
);
338 counter
->state
= PERF_COUNTER_STATE_OFF
;
341 spin_unlock_irqrestore(&ctx
->lock
, flags
);
347 static void perf_counter_disable(struct perf_counter
*counter
)
349 struct perf_counter_context
*ctx
= counter
->ctx
;
350 struct task_struct
*task
= ctx
->task
;
354 * Disable the counter on the cpu that it's on
356 smp_call_function_single(counter
->cpu
, __perf_counter_disable
,
362 task_oncpu_function_call(task
, __perf_counter_disable
, counter
);
364 spin_lock_irq(&ctx
->lock
);
366 * If the counter is still active, we need to retry the cross-call.
368 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
369 spin_unlock_irq(&ctx
->lock
);
374 * Since we have the lock this context can't be scheduled
375 * in, so we can change the state safely.
377 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
378 update_counter_times(counter
);
379 counter
->state
= PERF_COUNTER_STATE_OFF
;
382 spin_unlock_irq(&ctx
->lock
);
386 * Disable a counter and all its children.
388 static void perf_counter_disable_family(struct perf_counter
*counter
)
390 struct perf_counter
*child
;
392 perf_counter_disable(counter
);
395 * Lock the mutex to protect the list of children
397 mutex_lock(&counter
->mutex
);
398 list_for_each_entry(child
, &counter
->child_list
, child_list
)
399 perf_counter_disable(child
);
400 mutex_unlock(&counter
->mutex
);
404 counter_sched_in(struct perf_counter
*counter
,
405 struct perf_cpu_context
*cpuctx
,
406 struct perf_counter_context
*ctx
,
409 if (counter
->state
<= PERF_COUNTER_STATE_OFF
)
412 counter
->state
= PERF_COUNTER_STATE_ACTIVE
;
413 counter
->oncpu
= cpu
; /* TODO: put 'cpu' into cpuctx->cpu */
415 * The new state must be visible before we turn it on in the hardware:
419 if (counter
->pmu
->enable(counter
)) {
420 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
425 counter
->tstamp_running
+= ctx
->time
- counter
->tstamp_stopped
;
427 if (!is_software_counter(counter
))
428 cpuctx
->active_oncpu
++;
431 if (counter
->hw_event
.exclusive
)
432 cpuctx
->exclusive
= 1;
438 * Return 1 for a group consisting entirely of software counters,
439 * 0 if the group contains any hardware counters.
441 static int is_software_only_group(struct perf_counter
*leader
)
443 struct perf_counter
*counter
;
445 if (!is_software_counter(leader
))
448 list_for_each_entry(counter
, &leader
->sibling_list
, list_entry
)
449 if (!is_software_counter(counter
))
456 * Work out whether we can put this counter group on the CPU now.
458 static int group_can_go_on(struct perf_counter
*counter
,
459 struct perf_cpu_context
*cpuctx
,
463 * Groups consisting entirely of software counters can always go on.
465 if (is_software_only_group(counter
))
468 * If an exclusive group is already on, no other hardware
469 * counters can go on.
471 if (cpuctx
->exclusive
)
474 * If this group is exclusive and there are already
475 * counters on the CPU, it can't go on.
477 if (counter
->hw_event
.exclusive
&& cpuctx
->active_oncpu
)
480 * Otherwise, try to add it if all previous groups were able
486 static void add_counter_to_ctx(struct perf_counter
*counter
,
487 struct perf_counter_context
*ctx
)
489 list_add_counter(counter
, ctx
);
491 counter
->prev_state
= PERF_COUNTER_STATE_OFF
;
492 counter
->tstamp_enabled
= ctx
->time
;
493 counter
->tstamp_running
= ctx
->time
;
494 counter
->tstamp_stopped
= ctx
->time
;
498 * Cross CPU call to install and enable a performance counter
500 static void __perf_install_in_context(void *info
)
502 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
503 struct perf_counter
*counter
= info
;
504 struct perf_counter_context
*ctx
= counter
->ctx
;
505 struct perf_counter
*leader
= counter
->group_leader
;
506 int cpu
= smp_processor_id();
512 * If this is a task context, we need to check whether it is
513 * the current task context of this cpu. If not it has been
514 * scheduled out before the smp call arrived.
516 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
519 spin_lock_irqsave(&ctx
->lock
, flags
);
520 update_context_time(ctx
);
523 * Protect the list operation against NMI by disabling the
524 * counters on a global level. NOP for non NMI based counters.
526 perf_flags
= hw_perf_save_disable();
528 add_counter_to_ctx(counter
, ctx
);
531 * Don't put the counter on if it is disabled or if
532 * it is in a group and the group isn't on.
534 if (counter
->state
!= PERF_COUNTER_STATE_INACTIVE
||
535 (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
))
539 * An exclusive counter can't go on if there are already active
540 * hardware counters, and no hardware counter can go on if there
541 * is already an exclusive counter on.
543 if (!group_can_go_on(counter
, cpuctx
, 1))
546 err
= counter_sched_in(counter
, cpuctx
, ctx
, cpu
);
550 * This counter couldn't go on. If it is in a group
551 * then we have to pull the whole group off.
552 * If the counter group is pinned then put it in error state.
554 if (leader
!= counter
)
555 group_sched_out(leader
, cpuctx
, ctx
);
556 if (leader
->hw_event
.pinned
) {
557 update_group_times(leader
);
558 leader
->state
= PERF_COUNTER_STATE_ERROR
;
562 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
563 cpuctx
->max_pertask
--;
566 hw_perf_restore(perf_flags
);
568 spin_unlock_irqrestore(&ctx
->lock
, flags
);
572 * Attach a performance counter to a context
574 * First we add the counter to the list with the hardware enable bit
575 * in counter->hw_config cleared.
577 * If the counter is attached to a task which is on a CPU we use a smp
578 * call to enable it in the task context. The task might have been
579 * scheduled away, but we check this in the smp call again.
581 * Must be called with ctx->mutex held.
584 perf_install_in_context(struct perf_counter_context
*ctx
,
585 struct perf_counter
*counter
,
588 struct task_struct
*task
= ctx
->task
;
592 * Per cpu counters are installed via an smp call and
593 * the install is always sucessful.
595 smp_call_function_single(cpu
, __perf_install_in_context
,
600 counter
->task
= task
;
602 task_oncpu_function_call(task
, __perf_install_in_context
,
605 spin_lock_irq(&ctx
->lock
);
607 * we need to retry the smp call.
609 if (ctx
->is_active
&& list_empty(&counter
->list_entry
)) {
610 spin_unlock_irq(&ctx
->lock
);
615 * The lock prevents that this context is scheduled in so we
616 * can add the counter safely, if it the call above did not
619 if (list_empty(&counter
->list_entry
))
620 add_counter_to_ctx(counter
, ctx
);
621 spin_unlock_irq(&ctx
->lock
);
625 * Cross CPU call to enable a performance counter
627 static void __perf_counter_enable(void *info
)
629 struct perf_counter
*counter
= info
;
630 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
631 struct perf_counter_context
*ctx
= counter
->ctx
;
632 struct perf_counter
*leader
= counter
->group_leader
;
637 * If this is a per-task counter, need to check whether this
638 * counter's task is the current task on this cpu.
640 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
643 spin_lock_irqsave(&ctx
->lock
, flags
);
644 update_context_time(ctx
);
646 counter
->prev_state
= counter
->state
;
647 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
649 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
650 counter
->tstamp_enabled
= ctx
->time
- counter
->total_time_enabled
;
653 * If the counter is in a group and isn't the group leader,
654 * then don't put it on unless the group is on.
656 if (leader
!= counter
&& leader
->state
!= PERF_COUNTER_STATE_ACTIVE
)
659 if (!group_can_go_on(counter
, cpuctx
, 1))
662 err
= counter_sched_in(counter
, cpuctx
, ctx
,
667 * If this counter can't go on and it's part of a
668 * group, then the whole group has to come off.
670 if (leader
!= counter
)
671 group_sched_out(leader
, cpuctx
, ctx
);
672 if (leader
->hw_event
.pinned
) {
673 update_group_times(leader
);
674 leader
->state
= PERF_COUNTER_STATE_ERROR
;
679 spin_unlock_irqrestore(&ctx
->lock
, flags
);
685 static void perf_counter_enable(struct perf_counter
*counter
)
687 struct perf_counter_context
*ctx
= counter
->ctx
;
688 struct task_struct
*task
= ctx
->task
;
692 * Enable the counter on the cpu that it's on
694 smp_call_function_single(counter
->cpu
, __perf_counter_enable
,
699 spin_lock_irq(&ctx
->lock
);
700 if (counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
704 * If the counter is in error state, clear that first.
705 * That way, if we see the counter in error state below, we
706 * know that it has gone back into error state, as distinct
707 * from the task having been scheduled away before the
708 * cross-call arrived.
710 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
711 counter
->state
= PERF_COUNTER_STATE_OFF
;
714 spin_unlock_irq(&ctx
->lock
);
715 task_oncpu_function_call(task
, __perf_counter_enable
, counter
);
717 spin_lock_irq(&ctx
->lock
);
720 * If the context is active and the counter is still off,
721 * we need to retry the cross-call.
723 if (ctx
->is_active
&& counter
->state
== PERF_COUNTER_STATE_OFF
)
727 * Since we have the lock this context can't be scheduled
728 * in, so we can change the state safely.
730 if (counter
->state
== PERF_COUNTER_STATE_OFF
) {
731 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
732 counter
->tstamp_enabled
=
733 ctx
->time
- counter
->total_time_enabled
;
736 spin_unlock_irq(&ctx
->lock
);
739 static void perf_counter_refresh(struct perf_counter
*counter
, int refresh
)
741 atomic_add(refresh
, &counter
->event_limit
);
742 perf_counter_enable(counter
);
746 * Enable a counter and all its children.
748 static void perf_counter_enable_family(struct perf_counter
*counter
)
750 struct perf_counter
*child
;
752 perf_counter_enable(counter
);
755 * Lock the mutex to protect the list of children
757 mutex_lock(&counter
->mutex
);
758 list_for_each_entry(child
, &counter
->child_list
, child_list
)
759 perf_counter_enable(child
);
760 mutex_unlock(&counter
->mutex
);
763 void __perf_counter_sched_out(struct perf_counter_context
*ctx
,
764 struct perf_cpu_context
*cpuctx
)
766 struct perf_counter
*counter
;
769 spin_lock(&ctx
->lock
);
771 if (likely(!ctx
->nr_counters
))
773 update_context_time(ctx
);
775 flags
= hw_perf_save_disable();
776 if (ctx
->nr_active
) {
777 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
)
778 group_sched_out(counter
, cpuctx
, ctx
);
780 hw_perf_restore(flags
);
782 spin_unlock(&ctx
->lock
);
786 * Called from scheduler to remove the counters of the current task,
787 * with interrupts disabled.
789 * We stop each counter and update the counter value in counter->count.
791 * This does not protect us against NMI, but disable()
792 * sets the disabled bit in the control field of counter _before_
793 * accessing the counter control register. If a NMI hits, then it will
794 * not restart the counter.
796 void perf_counter_task_sched_out(struct task_struct
*task
, int cpu
)
798 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
799 struct perf_counter_context
*ctx
= &task
->perf_counter_ctx
;
800 struct pt_regs
*regs
;
802 if (likely(!cpuctx
->task_ctx
))
805 update_context_time(ctx
);
807 regs
= task_pt_regs(task
);
808 perf_swcounter_event(PERF_COUNT_CONTEXT_SWITCHES
, 1, 1, regs
, 0);
809 __perf_counter_sched_out(ctx
, cpuctx
);
811 cpuctx
->task_ctx
= NULL
;
814 static void perf_counter_cpu_sched_out(struct perf_cpu_context
*cpuctx
)
816 __perf_counter_sched_out(&cpuctx
->ctx
, cpuctx
);
820 group_sched_in(struct perf_counter
*group_counter
,
821 struct perf_cpu_context
*cpuctx
,
822 struct perf_counter_context
*ctx
,
825 struct perf_counter
*counter
, *partial_group
;
828 if (group_counter
->state
== PERF_COUNTER_STATE_OFF
)
831 ret
= hw_perf_group_sched_in(group_counter
, cpuctx
, ctx
, cpu
);
833 return ret
< 0 ? ret
: 0;
835 group_counter
->prev_state
= group_counter
->state
;
836 if (counter_sched_in(group_counter
, cpuctx
, ctx
, cpu
))
840 * Schedule in siblings as one group (if any):
842 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
843 counter
->prev_state
= counter
->state
;
844 if (counter_sched_in(counter
, cpuctx
, ctx
, cpu
)) {
845 partial_group
= counter
;
854 * Groups can be scheduled in as one unit only, so undo any
855 * partial group before returning:
857 list_for_each_entry(counter
, &group_counter
->sibling_list
, list_entry
) {
858 if (counter
== partial_group
)
860 counter_sched_out(counter
, cpuctx
, ctx
);
862 counter_sched_out(group_counter
, cpuctx
, ctx
);
868 __perf_counter_sched_in(struct perf_counter_context
*ctx
,
869 struct perf_cpu_context
*cpuctx
, int cpu
)
871 struct perf_counter
*counter
;
875 spin_lock(&ctx
->lock
);
877 if (likely(!ctx
->nr_counters
))
880 ctx
->timestamp
= perf_clock();
882 flags
= hw_perf_save_disable();
885 * First go through the list and put on any pinned groups
886 * in order to give them the best chance of going on.
888 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
889 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
890 !counter
->hw_event
.pinned
)
892 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
895 if (group_can_go_on(counter
, cpuctx
, 1))
896 group_sched_in(counter
, cpuctx
, ctx
, cpu
);
899 * If this pinned group hasn't been scheduled,
900 * put it in error state.
902 if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
903 update_group_times(counter
);
904 counter
->state
= PERF_COUNTER_STATE_ERROR
;
908 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
910 * Ignore counters in OFF or ERROR state, and
911 * ignore pinned counters since we did them already.
913 if (counter
->state
<= PERF_COUNTER_STATE_OFF
||
914 counter
->hw_event
.pinned
)
918 * Listen to the 'cpu' scheduling filter constraint
921 if (counter
->cpu
!= -1 && counter
->cpu
!= cpu
)
924 if (group_can_go_on(counter
, cpuctx
, can_add_hw
)) {
925 if (group_sched_in(counter
, cpuctx
, ctx
, cpu
))
929 hw_perf_restore(flags
);
931 spin_unlock(&ctx
->lock
);
935 * Called from scheduler to add the counters of the current task
936 * with interrupts disabled.
938 * We restore the counter value and then enable it.
940 * This does not protect us against NMI, but enable()
941 * sets the enabled bit in the control field of counter _before_
942 * accessing the counter control register. If a NMI hits, then it will
943 * keep the counter running.
945 void perf_counter_task_sched_in(struct task_struct
*task
, int cpu
)
947 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
948 struct perf_counter_context
*ctx
= &task
->perf_counter_ctx
;
950 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
951 cpuctx
->task_ctx
= ctx
;
954 static void perf_counter_cpu_sched_in(struct perf_cpu_context
*cpuctx
, int cpu
)
956 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
958 __perf_counter_sched_in(ctx
, cpuctx
, cpu
);
961 int perf_counter_task_disable(void)
963 struct task_struct
*curr
= current
;
964 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
965 struct perf_counter
*counter
;
970 if (likely(!ctx
->nr_counters
))
973 local_irq_save(flags
);
974 cpu
= smp_processor_id();
976 perf_counter_task_sched_out(curr
, cpu
);
978 spin_lock(&ctx
->lock
);
981 * Disable all the counters:
983 perf_flags
= hw_perf_save_disable();
985 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
986 if (counter
->state
!= PERF_COUNTER_STATE_ERROR
) {
987 update_group_times(counter
);
988 counter
->state
= PERF_COUNTER_STATE_OFF
;
992 hw_perf_restore(perf_flags
);
994 spin_unlock_irqrestore(&ctx
->lock
, flags
);
999 int perf_counter_task_enable(void)
1001 struct task_struct
*curr
= current
;
1002 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
1003 struct perf_counter
*counter
;
1004 unsigned long flags
;
1008 if (likely(!ctx
->nr_counters
))
1011 local_irq_save(flags
);
1012 cpu
= smp_processor_id();
1014 perf_counter_task_sched_out(curr
, cpu
);
1016 spin_lock(&ctx
->lock
);
1019 * Disable all the counters:
1021 perf_flags
= hw_perf_save_disable();
1023 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1024 if (counter
->state
> PERF_COUNTER_STATE_OFF
)
1026 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
1027 counter
->tstamp_enabled
=
1028 ctx
->time
- counter
->total_time_enabled
;
1029 counter
->hw_event
.disabled
= 0;
1031 hw_perf_restore(perf_flags
);
1033 spin_unlock(&ctx
->lock
);
1035 perf_counter_task_sched_in(curr
, cpu
);
1037 local_irq_restore(flags
);
1043 * Round-robin a context's counters:
1045 static void rotate_ctx(struct perf_counter_context
*ctx
)
1047 struct perf_counter
*counter
;
1050 if (!ctx
->nr_counters
)
1053 spin_lock(&ctx
->lock
);
1055 * Rotate the first entry last (works just fine for group counters too):
1057 perf_flags
= hw_perf_save_disable();
1058 list_for_each_entry(counter
, &ctx
->counter_list
, list_entry
) {
1059 list_move_tail(&counter
->list_entry
, &ctx
->counter_list
);
1062 hw_perf_restore(perf_flags
);
1064 spin_unlock(&ctx
->lock
);
1067 void perf_counter_task_tick(struct task_struct
*curr
, int cpu
)
1069 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1070 struct perf_counter_context
*ctx
= &curr
->perf_counter_ctx
;
1071 const int rotate_percpu
= 0;
1074 perf_counter_cpu_sched_out(cpuctx
);
1075 perf_counter_task_sched_out(curr
, cpu
);
1078 rotate_ctx(&cpuctx
->ctx
);
1082 perf_counter_cpu_sched_in(cpuctx
, cpu
);
1083 perf_counter_task_sched_in(curr
, cpu
);
1087 * Cross CPU call to read the hardware counter
1089 static void __read(void *info
)
1091 struct perf_counter
*counter
= info
;
1092 struct perf_counter_context
*ctx
= counter
->ctx
;
1093 unsigned long flags
;
1095 local_irq_save(flags
);
1097 update_context_time(ctx
);
1098 counter
->pmu
->read(counter
);
1099 update_counter_times(counter
);
1100 local_irq_restore(flags
);
1103 static u64
perf_counter_read(struct perf_counter
*counter
)
1106 * If counter is enabled and currently active on a CPU, update the
1107 * value in the counter structure:
1109 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
) {
1110 smp_call_function_single(counter
->oncpu
,
1111 __read
, counter
, 1);
1112 } else if (counter
->state
== PERF_COUNTER_STATE_INACTIVE
) {
1113 update_counter_times(counter
);
1116 return atomic64_read(&counter
->count
);
1119 static void put_context(struct perf_counter_context
*ctx
)
1122 put_task_struct(ctx
->task
);
1125 static struct perf_counter_context
*find_get_context(pid_t pid
, int cpu
)
1127 struct perf_cpu_context
*cpuctx
;
1128 struct perf_counter_context
*ctx
;
1129 struct task_struct
*task
;
1132 * If cpu is not a wildcard then this is a percpu counter:
1135 /* Must be root to operate on a CPU counter: */
1136 if (sysctl_perf_counter_priv
&& !capable(CAP_SYS_ADMIN
))
1137 return ERR_PTR(-EACCES
);
1139 if (cpu
< 0 || cpu
> num_possible_cpus())
1140 return ERR_PTR(-EINVAL
);
1143 * We could be clever and allow to attach a counter to an
1144 * offline CPU and activate it when the CPU comes up, but
1147 if (!cpu_isset(cpu
, cpu_online_map
))
1148 return ERR_PTR(-ENODEV
);
1150 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1160 task
= find_task_by_vpid(pid
);
1162 get_task_struct(task
);
1166 return ERR_PTR(-ESRCH
);
1168 ctx
= &task
->perf_counter_ctx
;
1171 /* Reuse ptrace permission checks for now. */
1172 if (!ptrace_may_access(task
, PTRACE_MODE_READ
)) {
1174 return ERR_PTR(-EACCES
);
1180 static void free_counter_rcu(struct rcu_head
*head
)
1182 struct perf_counter
*counter
;
1184 counter
= container_of(head
, struct perf_counter
, rcu_head
);
1188 static void perf_pending_sync(struct perf_counter
*counter
);
1190 static void free_counter(struct perf_counter
*counter
)
1192 perf_pending_sync(counter
);
1194 if (counter
->hw_event
.mmap
)
1195 atomic_dec(&nr_mmap_tracking
);
1196 if (counter
->hw_event
.munmap
)
1197 atomic_dec(&nr_munmap_tracking
);
1198 if (counter
->hw_event
.comm
)
1199 atomic_dec(&nr_comm_tracking
);
1201 if (counter
->destroy
)
1202 counter
->destroy(counter
);
1204 call_rcu(&counter
->rcu_head
, free_counter_rcu
);
1208 * Called when the last reference to the file is gone.
1210 static int perf_release(struct inode
*inode
, struct file
*file
)
1212 struct perf_counter
*counter
= file
->private_data
;
1213 struct perf_counter_context
*ctx
= counter
->ctx
;
1215 file
->private_data
= NULL
;
1217 mutex_lock(&ctx
->mutex
);
1218 mutex_lock(&counter
->mutex
);
1220 perf_counter_remove_from_context(counter
);
1222 mutex_unlock(&counter
->mutex
);
1223 mutex_unlock(&ctx
->mutex
);
1225 free_counter(counter
);
1232 * Read the performance counter - simple non blocking version for now
1235 perf_read_hw(struct perf_counter
*counter
, char __user
*buf
, size_t count
)
1241 * Return end-of-file for a read on a counter that is in
1242 * error state (i.e. because it was pinned but it couldn't be
1243 * scheduled on to the CPU at some point).
1245 if (counter
->state
== PERF_COUNTER_STATE_ERROR
)
1248 mutex_lock(&counter
->mutex
);
1249 values
[0] = perf_counter_read(counter
);
1251 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1252 values
[n
++] = counter
->total_time_enabled
+
1253 atomic64_read(&counter
->child_total_time_enabled
);
1254 if (counter
->hw_event
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1255 values
[n
++] = counter
->total_time_running
+
1256 atomic64_read(&counter
->child_total_time_running
);
1257 mutex_unlock(&counter
->mutex
);
1259 if (count
< n
* sizeof(u64
))
1261 count
= n
* sizeof(u64
);
1263 if (copy_to_user(buf
, values
, count
))
1270 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
1272 struct perf_counter
*counter
= file
->private_data
;
1274 return perf_read_hw(counter
, buf
, count
);
1277 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
1279 struct perf_counter
*counter
= file
->private_data
;
1280 struct perf_mmap_data
*data
;
1281 unsigned int events
;
1284 data
= rcu_dereference(counter
->data
);
1286 events
= atomic_xchg(&data
->wakeup
, 0);
1291 poll_wait(file
, &counter
->waitq
, wait
);
1296 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
1298 struct perf_counter
*counter
= file
->private_data
;
1302 case PERF_COUNTER_IOC_ENABLE
:
1303 perf_counter_enable_family(counter
);
1305 case PERF_COUNTER_IOC_DISABLE
:
1306 perf_counter_disable_family(counter
);
1308 case PERF_COUNTER_IOC_REFRESH
:
1309 perf_counter_refresh(counter
, arg
);
1318 * Callers need to ensure there can be no nesting of this function, otherwise
1319 * the seqlock logic goes bad. We can not serialize this because the arch
1320 * code calls this from NMI context.
1322 void perf_counter_update_userpage(struct perf_counter
*counter
)
1324 struct perf_mmap_data
*data
;
1325 struct perf_counter_mmap_page
*userpg
;
1328 data
= rcu_dereference(counter
->data
);
1332 userpg
= data
->user_page
;
1335 * Disable preemption so as to not let the corresponding user-space
1336 * spin too long if we get preempted.
1341 userpg
->index
= counter
->hw
.idx
;
1342 userpg
->offset
= atomic64_read(&counter
->count
);
1343 if (counter
->state
== PERF_COUNTER_STATE_ACTIVE
)
1344 userpg
->offset
-= atomic64_read(&counter
->hw
.prev_count
);
1353 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1355 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1356 struct perf_mmap_data
*data
;
1357 int ret
= VM_FAULT_SIGBUS
;
1360 data
= rcu_dereference(counter
->data
);
1364 if (vmf
->pgoff
== 0) {
1365 vmf
->page
= virt_to_page(data
->user_page
);
1367 int nr
= vmf
->pgoff
- 1;
1369 if ((unsigned)nr
> data
->nr_pages
)
1372 vmf
->page
= virt_to_page(data
->data_pages
[nr
]);
1374 get_page(vmf
->page
);
1382 static int perf_mmap_data_alloc(struct perf_counter
*counter
, int nr_pages
)
1384 struct perf_mmap_data
*data
;
1388 WARN_ON(atomic_read(&counter
->mmap_count
));
1390 size
= sizeof(struct perf_mmap_data
);
1391 size
+= nr_pages
* sizeof(void *);
1393 data
= kzalloc(size
, GFP_KERNEL
);
1397 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
1398 if (!data
->user_page
)
1399 goto fail_user_page
;
1401 for (i
= 0; i
< nr_pages
; i
++) {
1402 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
1403 if (!data
->data_pages
[i
])
1404 goto fail_data_pages
;
1407 data
->nr_pages
= nr_pages
;
1409 rcu_assign_pointer(counter
->data
, data
);
1414 for (i
--; i
>= 0; i
--)
1415 free_page((unsigned long)data
->data_pages
[i
]);
1417 free_page((unsigned long)data
->user_page
);
1426 static void __perf_mmap_data_free(struct rcu_head
*rcu_head
)
1428 struct perf_mmap_data
*data
= container_of(rcu_head
,
1429 struct perf_mmap_data
, rcu_head
);
1432 free_page((unsigned long)data
->user_page
);
1433 for (i
= 0; i
< data
->nr_pages
; i
++)
1434 free_page((unsigned long)data
->data_pages
[i
]);
1438 static void perf_mmap_data_free(struct perf_counter
*counter
)
1440 struct perf_mmap_data
*data
= counter
->data
;
1442 WARN_ON(atomic_read(&counter
->mmap_count
));
1444 rcu_assign_pointer(counter
->data
, NULL
);
1445 call_rcu(&data
->rcu_head
, __perf_mmap_data_free
);
1448 static void perf_mmap_open(struct vm_area_struct
*vma
)
1450 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1452 atomic_inc(&counter
->mmap_count
);
1455 static void perf_mmap_close(struct vm_area_struct
*vma
)
1457 struct perf_counter
*counter
= vma
->vm_file
->private_data
;
1459 if (atomic_dec_and_mutex_lock(&counter
->mmap_count
,
1460 &counter
->mmap_mutex
)) {
1461 vma
->vm_mm
->locked_vm
-= counter
->data
->nr_pages
+ 1;
1462 perf_mmap_data_free(counter
);
1463 mutex_unlock(&counter
->mmap_mutex
);
1467 static struct vm_operations_struct perf_mmap_vmops
= {
1468 .open
= perf_mmap_open
,
1469 .close
= perf_mmap_close
,
1470 .fault
= perf_mmap_fault
,
1473 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1475 struct perf_counter
*counter
= file
->private_data
;
1476 unsigned long vma_size
;
1477 unsigned long nr_pages
;
1478 unsigned long locked
, lock_limit
;
1481 if (!(vma
->vm_flags
& VM_SHARED
) || (vma
->vm_flags
& VM_WRITE
))
1484 vma_size
= vma
->vm_end
- vma
->vm_start
;
1485 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
1488 * If we have data pages ensure they're a power-of-two number, so we
1489 * can do bitmasks instead of modulo.
1491 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
1494 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
1497 if (vma
->vm_pgoff
!= 0)
1500 mutex_lock(&counter
->mmap_mutex
);
1501 if (atomic_inc_not_zero(&counter
->mmap_count
)) {
1502 if (nr_pages
!= counter
->data
->nr_pages
)
1507 locked
= vma
->vm_mm
->locked_vm
;
1508 locked
+= nr_pages
+ 1;
1510 lock_limit
= current
->signal
->rlim
[RLIMIT_MEMLOCK
].rlim_cur
;
1511 lock_limit
>>= PAGE_SHIFT
;
1513 if ((locked
> lock_limit
) && !capable(CAP_IPC_LOCK
)) {
1518 WARN_ON(counter
->data
);
1519 ret
= perf_mmap_data_alloc(counter
, nr_pages
);
1523 atomic_set(&counter
->mmap_count
, 1);
1524 vma
->vm_mm
->locked_vm
+= nr_pages
+ 1;
1526 mutex_unlock(&counter
->mmap_mutex
);
1528 vma
->vm_flags
&= ~VM_MAYWRITE
;
1529 vma
->vm_flags
|= VM_RESERVED
;
1530 vma
->vm_ops
= &perf_mmap_vmops
;
1535 static int perf_fasync(int fd
, struct file
*filp
, int on
)
1537 struct perf_counter
*counter
= filp
->private_data
;
1538 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
1541 mutex_lock(&inode
->i_mutex
);
1542 retval
= fasync_helper(fd
, filp
, on
, &counter
->fasync
);
1543 mutex_unlock(&inode
->i_mutex
);
1551 static const struct file_operations perf_fops
= {
1552 .release
= perf_release
,
1555 .unlocked_ioctl
= perf_ioctl
,
1556 .compat_ioctl
= perf_ioctl
,
1558 .fasync
= perf_fasync
,
1562 * Perf counter wakeup
1564 * If there's data, ensure we set the poll() state and publish everything
1565 * to user-space before waking everybody up.
1568 void perf_counter_wakeup(struct perf_counter
*counter
)
1570 struct perf_mmap_data
*data
;
1573 data
= rcu_dereference(counter
->data
);
1575 atomic_set(&data
->wakeup
, POLL_IN
);
1577 * Ensure all data writes are issued before updating the
1578 * user-space data head information. The matching rmb()
1579 * will be in userspace after reading this value.
1582 data
->user_page
->data_head
= atomic_read(&data
->head
);
1586 wake_up_all(&counter
->waitq
);
1588 if (counter
->pending_kill
) {
1589 kill_fasync(&counter
->fasync
, SIGIO
, counter
->pending_kill
);
1590 counter
->pending_kill
= 0;
1597 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
1599 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
1600 * single linked list and use cmpxchg() to add entries lockless.
1603 static void perf_pending_counter(struct perf_pending_entry
*entry
)
1605 struct perf_counter
*counter
= container_of(entry
,
1606 struct perf_counter
, pending
);
1608 if (counter
->pending_disable
) {
1609 counter
->pending_disable
= 0;
1610 perf_counter_disable(counter
);
1613 if (counter
->pending_wakeup
) {
1614 counter
->pending_wakeup
= 0;
1615 perf_counter_wakeup(counter
);
1619 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
1621 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
1625 static void perf_pending_queue(struct perf_pending_entry
*entry
,
1626 void (*func
)(struct perf_pending_entry
*))
1628 struct perf_pending_entry
**head
;
1630 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
1635 head
= &get_cpu_var(perf_pending_head
);
1638 entry
->next
= *head
;
1639 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
1641 set_perf_counter_pending();
1643 put_cpu_var(perf_pending_head
);
1646 static int __perf_pending_run(void)
1648 struct perf_pending_entry
*list
;
1651 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
1652 while (list
!= PENDING_TAIL
) {
1653 void (*func
)(struct perf_pending_entry
*);
1654 struct perf_pending_entry
*entry
= list
;
1661 * Ensure we observe the unqueue before we issue the wakeup,
1662 * so that we won't be waiting forever.
1663 * -- see perf_not_pending().
1674 static inline int perf_not_pending(struct perf_counter
*counter
)
1677 * If we flush on whatever cpu we run, there is a chance we don't
1681 __perf_pending_run();
1685 * Ensure we see the proper queue state before going to sleep
1686 * so that we do not miss the wakeup. -- see perf_pending_handle()
1689 return counter
->pending
.next
== NULL
;
1692 static void perf_pending_sync(struct perf_counter
*counter
)
1694 wait_event(counter
->waitq
, perf_not_pending(counter
));
1697 void perf_counter_do_pending(void)
1699 __perf_pending_run();
1703 * Callchain support -- arch specific
1706 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
1715 struct perf_output_handle
{
1716 struct perf_counter
*counter
;
1717 struct perf_mmap_data
*data
;
1718 unsigned int offset
;
1725 static inline void __perf_output_wakeup(struct perf_output_handle
*handle
)
1728 handle
->counter
->pending_wakeup
= 1;
1729 perf_pending_queue(&handle
->counter
->pending
,
1730 perf_pending_counter
);
1732 perf_counter_wakeup(handle
->counter
);
1735 static int perf_output_begin(struct perf_output_handle
*handle
,
1736 struct perf_counter
*counter
, unsigned int size
,
1737 int nmi
, int overflow
)
1739 struct perf_mmap_data
*data
;
1740 unsigned int offset
, head
;
1743 data
= rcu_dereference(counter
->data
);
1747 handle
->counter
= counter
;
1749 handle
->overflow
= overflow
;
1751 if (!data
->nr_pages
)
1755 offset
= head
= atomic_read(&data
->head
);
1757 } while (atomic_cmpxchg(&data
->head
, offset
, head
) != offset
);
1759 handle
->data
= data
;
1760 handle
->offset
= offset
;
1761 handle
->head
= head
;
1762 handle
->wakeup
= (offset
>> PAGE_SHIFT
) != (head
>> PAGE_SHIFT
);
1767 __perf_output_wakeup(handle
);
1774 static void perf_output_copy(struct perf_output_handle
*handle
,
1775 void *buf
, unsigned int len
)
1777 unsigned int pages_mask
;
1778 unsigned int offset
;
1782 offset
= handle
->offset
;
1783 pages_mask
= handle
->data
->nr_pages
- 1;
1784 pages
= handle
->data
->data_pages
;
1787 unsigned int page_offset
;
1790 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
1791 page_offset
= offset
& (PAGE_SIZE
- 1);
1792 size
= min_t(unsigned int, PAGE_SIZE
- page_offset
, len
);
1794 memcpy(pages
[nr
] + page_offset
, buf
, size
);
1801 handle
->offset
= offset
;
1803 WARN_ON_ONCE(handle
->offset
> handle
->head
);
1806 #define perf_output_put(handle, x) \
1807 perf_output_copy((handle), &(x), sizeof(x))
1809 static void perf_output_end(struct perf_output_handle
*handle
)
1811 int wakeup_events
= handle
->counter
->hw_event
.wakeup_events
;
1813 if (handle
->overflow
&& wakeup_events
) {
1814 int events
= atomic_inc_return(&handle
->data
->events
);
1815 if (events
>= wakeup_events
) {
1816 atomic_sub(wakeup_events
, &handle
->data
->events
);
1817 __perf_output_wakeup(handle
);
1819 } else if (handle
->wakeup
)
1820 __perf_output_wakeup(handle
);
1824 static void perf_counter_output(struct perf_counter
*counter
,
1825 int nmi
, struct pt_regs
*regs
, u64 addr
)
1828 u64 record_type
= counter
->hw_event
.record_type
;
1829 struct perf_output_handle handle
;
1830 struct perf_event_header header
;
1839 struct perf_callchain_entry
*callchain
= NULL
;
1840 int callchain_size
= 0;
1844 header
.size
= sizeof(header
);
1846 header
.misc
= PERF_EVENT_MISC_OVERFLOW
;
1847 header
.misc
|= user_mode(regs
) ?
1848 PERF_EVENT_MISC_USER
: PERF_EVENT_MISC_KERNEL
;
1850 if (record_type
& PERF_RECORD_IP
) {
1851 ip
= instruction_pointer(regs
);
1852 header
.type
|= PERF_RECORD_IP
;
1853 header
.size
+= sizeof(ip
);
1856 if (record_type
& PERF_RECORD_TID
) {
1857 /* namespace issues */
1858 tid_entry
.pid
= current
->group_leader
->pid
;
1859 tid_entry
.tid
= current
->pid
;
1861 header
.type
|= PERF_RECORD_TID
;
1862 header
.size
+= sizeof(tid_entry
);
1865 if (record_type
& PERF_RECORD_TIME
) {
1867 * Maybe do better on x86 and provide cpu_clock_nmi()
1869 time
= sched_clock();
1871 header
.type
|= PERF_RECORD_TIME
;
1872 header
.size
+= sizeof(u64
);
1875 if (record_type
& PERF_RECORD_ADDR
) {
1876 header
.type
|= PERF_RECORD_ADDR
;
1877 header
.size
+= sizeof(u64
);
1880 if (record_type
& PERF_RECORD_GROUP
) {
1881 header
.type
|= PERF_RECORD_GROUP
;
1882 header
.size
+= sizeof(u64
) +
1883 counter
->nr_siblings
* sizeof(group_entry
);
1886 if (record_type
& PERF_RECORD_CALLCHAIN
) {
1887 callchain
= perf_callchain(regs
);
1890 callchain_size
= (1 + callchain
->nr
) * sizeof(u64
);
1892 header
.type
|= PERF_RECORD_CALLCHAIN
;
1893 header
.size
+= callchain_size
;
1897 ret
= perf_output_begin(&handle
, counter
, header
.size
, nmi
, 1);
1901 perf_output_put(&handle
, header
);
1903 if (record_type
& PERF_RECORD_IP
)
1904 perf_output_put(&handle
, ip
);
1906 if (record_type
& PERF_RECORD_TID
)
1907 perf_output_put(&handle
, tid_entry
);
1909 if (record_type
& PERF_RECORD_TIME
)
1910 perf_output_put(&handle
, time
);
1912 if (record_type
& PERF_RECORD_ADDR
)
1913 perf_output_put(&handle
, addr
);
1915 if (record_type
& PERF_RECORD_GROUP
) {
1916 struct perf_counter
*leader
, *sub
;
1917 u64 nr
= counter
->nr_siblings
;
1919 perf_output_put(&handle
, nr
);
1921 leader
= counter
->group_leader
;
1922 list_for_each_entry(sub
, &leader
->sibling_list
, list_entry
) {
1924 sub
->pmu
->read(sub
);
1926 group_entry
.event
= sub
->hw_event
.config
;
1927 group_entry
.counter
= atomic64_read(&sub
->count
);
1929 perf_output_put(&handle
, group_entry
);
1934 perf_output_copy(&handle
, callchain
, callchain_size
);
1936 perf_output_end(&handle
);
1943 struct perf_comm_event
{
1944 struct task_struct
*task
;
1949 struct perf_event_header header
;
1956 static void perf_counter_comm_output(struct perf_counter
*counter
,
1957 struct perf_comm_event
*comm_event
)
1959 struct perf_output_handle handle
;
1960 int size
= comm_event
->event
.header
.size
;
1961 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
1966 perf_output_put(&handle
, comm_event
->event
);
1967 perf_output_copy(&handle
, comm_event
->comm
,
1968 comm_event
->comm_size
);
1969 perf_output_end(&handle
);
1972 static int perf_counter_comm_match(struct perf_counter
*counter
,
1973 struct perf_comm_event
*comm_event
)
1975 if (counter
->hw_event
.comm
&&
1976 comm_event
->event
.header
.type
== PERF_EVENT_COMM
)
1982 static void perf_counter_comm_ctx(struct perf_counter_context
*ctx
,
1983 struct perf_comm_event
*comm_event
)
1985 struct perf_counter
*counter
;
1987 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
1991 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
1992 if (perf_counter_comm_match(counter
, comm_event
))
1993 perf_counter_comm_output(counter
, comm_event
);
1998 static void perf_counter_comm_event(struct perf_comm_event
*comm_event
)
2000 struct perf_cpu_context
*cpuctx
;
2002 char *comm
= comm_event
->task
->comm
;
2004 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
2006 comm_event
->comm
= comm
;
2007 comm_event
->comm_size
= size
;
2009 comm_event
->event
.header
.size
= sizeof(comm_event
->event
) + size
;
2011 cpuctx
= &get_cpu_var(perf_cpu_context
);
2012 perf_counter_comm_ctx(&cpuctx
->ctx
, comm_event
);
2013 put_cpu_var(perf_cpu_context
);
2015 perf_counter_comm_ctx(¤t
->perf_counter_ctx
, comm_event
);
2018 void perf_counter_comm(struct task_struct
*task
)
2020 struct perf_comm_event comm_event
;
2022 if (!atomic_read(&nr_comm_tracking
))
2025 comm_event
= (struct perf_comm_event
){
2028 .header
= { .type
= PERF_EVENT_COMM
, },
2029 .pid
= task
->group_leader
->pid
,
2034 perf_counter_comm_event(&comm_event
);
2041 struct perf_mmap_event
{
2047 struct perf_event_header header
;
2057 static void perf_counter_mmap_output(struct perf_counter
*counter
,
2058 struct perf_mmap_event
*mmap_event
)
2060 struct perf_output_handle handle
;
2061 int size
= mmap_event
->event
.header
.size
;
2062 int ret
= perf_output_begin(&handle
, counter
, size
, 0, 0);
2067 perf_output_put(&handle
, mmap_event
->event
);
2068 perf_output_copy(&handle
, mmap_event
->file_name
,
2069 mmap_event
->file_size
);
2070 perf_output_end(&handle
);
2073 static int perf_counter_mmap_match(struct perf_counter
*counter
,
2074 struct perf_mmap_event
*mmap_event
)
2076 if (counter
->hw_event
.mmap
&&
2077 mmap_event
->event
.header
.type
== PERF_EVENT_MMAP
)
2080 if (counter
->hw_event
.munmap
&&
2081 mmap_event
->event
.header
.type
== PERF_EVENT_MUNMAP
)
2087 static void perf_counter_mmap_ctx(struct perf_counter_context
*ctx
,
2088 struct perf_mmap_event
*mmap_event
)
2090 struct perf_counter
*counter
;
2092 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2096 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2097 if (perf_counter_mmap_match(counter
, mmap_event
))
2098 perf_counter_mmap_output(counter
, mmap_event
);
2103 static void perf_counter_mmap_event(struct perf_mmap_event
*mmap_event
)
2105 struct perf_cpu_context
*cpuctx
;
2106 struct file
*file
= mmap_event
->file
;
2113 buf
= kzalloc(PATH_MAX
, GFP_KERNEL
);
2115 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
2118 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
2120 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
2124 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
2129 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
2131 mmap_event
->file_name
= name
;
2132 mmap_event
->file_size
= size
;
2134 mmap_event
->event
.header
.size
= sizeof(mmap_event
->event
) + size
;
2136 cpuctx
= &get_cpu_var(perf_cpu_context
);
2137 perf_counter_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
2138 put_cpu_var(perf_cpu_context
);
2140 perf_counter_mmap_ctx(¤t
->perf_counter_ctx
, mmap_event
);
2145 void perf_counter_mmap(unsigned long addr
, unsigned long len
,
2146 unsigned long pgoff
, struct file
*file
)
2148 struct perf_mmap_event mmap_event
;
2150 if (!atomic_read(&nr_mmap_tracking
))
2153 mmap_event
= (struct perf_mmap_event
){
2156 .header
= { .type
= PERF_EVENT_MMAP
, },
2157 .pid
= current
->group_leader
->pid
,
2158 .tid
= current
->pid
,
2165 perf_counter_mmap_event(&mmap_event
);
2168 void perf_counter_munmap(unsigned long addr
, unsigned long len
,
2169 unsigned long pgoff
, struct file
*file
)
2171 struct perf_mmap_event mmap_event
;
2173 if (!atomic_read(&nr_munmap_tracking
))
2176 mmap_event
= (struct perf_mmap_event
){
2179 .header
= { .type
= PERF_EVENT_MUNMAP
, },
2180 .pid
= current
->group_leader
->pid
,
2181 .tid
= current
->pid
,
2188 perf_counter_mmap_event(&mmap_event
);
2192 * Generic counter overflow handling.
2195 int perf_counter_overflow(struct perf_counter
*counter
,
2196 int nmi
, struct pt_regs
*regs
, u64 addr
)
2198 int events
= atomic_read(&counter
->event_limit
);
2201 counter
->pending_kill
= POLL_IN
;
2202 if (events
&& atomic_dec_and_test(&counter
->event_limit
)) {
2204 counter
->pending_kill
= POLL_HUP
;
2206 counter
->pending_disable
= 1;
2207 perf_pending_queue(&counter
->pending
,
2208 perf_pending_counter
);
2210 perf_counter_disable(counter
);
2213 perf_counter_output(counter
, nmi
, regs
, addr
);
2218 * Generic software counter infrastructure
2221 static void perf_swcounter_update(struct perf_counter
*counter
)
2223 struct hw_perf_counter
*hwc
= &counter
->hw
;
2228 prev
= atomic64_read(&hwc
->prev_count
);
2229 now
= atomic64_read(&hwc
->count
);
2230 if (atomic64_cmpxchg(&hwc
->prev_count
, prev
, now
) != prev
)
2235 atomic64_add(delta
, &counter
->count
);
2236 atomic64_sub(delta
, &hwc
->period_left
);
2239 static void perf_swcounter_set_period(struct perf_counter
*counter
)
2241 struct hw_perf_counter
*hwc
= &counter
->hw
;
2242 s64 left
= atomic64_read(&hwc
->period_left
);
2243 s64 period
= hwc
->irq_period
;
2245 if (unlikely(left
<= -period
)) {
2247 atomic64_set(&hwc
->period_left
, left
);
2250 if (unlikely(left
<= 0)) {
2252 atomic64_add(period
, &hwc
->period_left
);
2255 atomic64_set(&hwc
->prev_count
, -left
);
2256 atomic64_set(&hwc
->count
, -left
);
2259 static enum hrtimer_restart
perf_swcounter_hrtimer(struct hrtimer
*hrtimer
)
2261 enum hrtimer_restart ret
= HRTIMER_RESTART
;
2262 struct perf_counter
*counter
;
2263 struct pt_regs
*regs
;
2265 counter
= container_of(hrtimer
, struct perf_counter
, hw
.hrtimer
);
2266 counter
->pmu
->read(counter
);
2268 regs
= get_irq_regs();
2270 * In case we exclude kernel IPs or are somehow not in interrupt
2271 * context, provide the next best thing, the user IP.
2273 if ((counter
->hw_event
.exclude_kernel
|| !regs
) &&
2274 !counter
->hw_event
.exclude_user
)
2275 regs
= task_pt_regs(current
);
2278 if (perf_counter_overflow(counter
, 0, regs
, 0))
2279 ret
= HRTIMER_NORESTART
;
2282 hrtimer_forward_now(hrtimer
, ns_to_ktime(counter
->hw
.irq_period
));
2287 static void perf_swcounter_overflow(struct perf_counter
*counter
,
2288 int nmi
, struct pt_regs
*regs
, u64 addr
)
2290 perf_swcounter_update(counter
);
2291 perf_swcounter_set_period(counter
);
2292 if (perf_counter_overflow(counter
, nmi
, regs
, addr
))
2293 /* soft-disable the counter */
2298 static int perf_swcounter_match(struct perf_counter
*counter
,
2299 enum perf_event_types type
,
2300 u32 event
, struct pt_regs
*regs
)
2302 if (counter
->state
!= PERF_COUNTER_STATE_ACTIVE
)
2305 if (perf_event_raw(&counter
->hw_event
))
2308 if (perf_event_type(&counter
->hw_event
) != type
)
2311 if (perf_event_id(&counter
->hw_event
) != event
)
2314 if (counter
->hw_event
.exclude_user
&& user_mode(regs
))
2317 if (counter
->hw_event
.exclude_kernel
&& !user_mode(regs
))
2323 static void perf_swcounter_add(struct perf_counter
*counter
, u64 nr
,
2324 int nmi
, struct pt_regs
*regs
, u64 addr
)
2326 int neg
= atomic64_add_negative(nr
, &counter
->hw
.count
);
2327 if (counter
->hw
.irq_period
&& !neg
)
2328 perf_swcounter_overflow(counter
, nmi
, regs
, addr
);
2331 static void perf_swcounter_ctx_event(struct perf_counter_context
*ctx
,
2332 enum perf_event_types type
, u32 event
,
2333 u64 nr
, int nmi
, struct pt_regs
*regs
,
2336 struct perf_counter
*counter
;
2338 if (system_state
!= SYSTEM_RUNNING
|| list_empty(&ctx
->event_list
))
2342 list_for_each_entry_rcu(counter
, &ctx
->event_list
, event_entry
) {
2343 if (perf_swcounter_match(counter
, type
, event
, regs
))
2344 perf_swcounter_add(counter
, nr
, nmi
, regs
, addr
);
2349 static int *perf_swcounter_recursion_context(struct perf_cpu_context
*cpuctx
)
2352 return &cpuctx
->recursion
[3];
2355 return &cpuctx
->recursion
[2];
2358 return &cpuctx
->recursion
[1];
2360 return &cpuctx
->recursion
[0];
2363 static void __perf_swcounter_event(enum perf_event_types type
, u32 event
,
2364 u64 nr
, int nmi
, struct pt_regs
*regs
,
2367 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
2368 int *recursion
= perf_swcounter_recursion_context(cpuctx
);
2376 perf_swcounter_ctx_event(&cpuctx
->ctx
, type
, event
,
2377 nr
, nmi
, regs
, addr
);
2378 if (cpuctx
->task_ctx
) {
2379 perf_swcounter_ctx_event(cpuctx
->task_ctx
, type
, event
,
2380 nr
, nmi
, regs
, addr
);
2387 put_cpu_var(perf_cpu_context
);
2391 perf_swcounter_event(u32 event
, u64 nr
, int nmi
, struct pt_regs
*regs
, u64 addr
)
2393 __perf_swcounter_event(PERF_TYPE_SOFTWARE
, event
, nr
, nmi
, regs
, addr
);
2396 static void perf_swcounter_read(struct perf_counter
*counter
)
2398 perf_swcounter_update(counter
);
2401 static int perf_swcounter_enable(struct perf_counter
*counter
)
2403 perf_swcounter_set_period(counter
);
2407 static void perf_swcounter_disable(struct perf_counter
*counter
)
2409 perf_swcounter_update(counter
);
2412 static const struct pmu perf_ops_generic
= {
2413 .enable
= perf_swcounter_enable
,
2414 .disable
= perf_swcounter_disable
,
2415 .read
= perf_swcounter_read
,
2419 * Software counter: cpu wall time clock
2422 static void cpu_clock_perf_counter_update(struct perf_counter
*counter
)
2424 int cpu
= raw_smp_processor_id();
2428 now
= cpu_clock(cpu
);
2429 prev
= atomic64_read(&counter
->hw
.prev_count
);
2430 atomic64_set(&counter
->hw
.prev_count
, now
);
2431 atomic64_add(now
- prev
, &counter
->count
);
2434 static int cpu_clock_perf_counter_enable(struct perf_counter
*counter
)
2436 struct hw_perf_counter
*hwc
= &counter
->hw
;
2437 int cpu
= raw_smp_processor_id();
2439 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
2440 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2441 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2442 if (hwc
->irq_period
) {
2443 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2444 ns_to_ktime(hwc
->irq_period
), 0,
2445 HRTIMER_MODE_REL
, 0);
2451 static void cpu_clock_perf_counter_disable(struct perf_counter
*counter
)
2453 hrtimer_cancel(&counter
->hw
.hrtimer
);
2454 cpu_clock_perf_counter_update(counter
);
2457 static void cpu_clock_perf_counter_read(struct perf_counter
*counter
)
2459 cpu_clock_perf_counter_update(counter
);
2462 static const struct pmu perf_ops_cpu_clock
= {
2463 .enable
= cpu_clock_perf_counter_enable
,
2464 .disable
= cpu_clock_perf_counter_disable
,
2465 .read
= cpu_clock_perf_counter_read
,
2469 * Software counter: task time clock
2472 static void task_clock_perf_counter_update(struct perf_counter
*counter
, u64 now
)
2477 prev
= atomic64_xchg(&counter
->hw
.prev_count
, now
);
2479 atomic64_add(delta
, &counter
->count
);
2482 static int task_clock_perf_counter_enable(struct perf_counter
*counter
)
2484 struct hw_perf_counter
*hwc
= &counter
->hw
;
2487 now
= counter
->ctx
->time
;
2489 atomic64_set(&hwc
->prev_count
, now
);
2490 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
2491 hwc
->hrtimer
.function
= perf_swcounter_hrtimer
;
2492 if (hwc
->irq_period
) {
2493 __hrtimer_start_range_ns(&hwc
->hrtimer
,
2494 ns_to_ktime(hwc
->irq_period
), 0,
2495 HRTIMER_MODE_REL
, 0);
2501 static void task_clock_perf_counter_disable(struct perf_counter
*counter
)
2503 hrtimer_cancel(&counter
->hw
.hrtimer
);
2504 task_clock_perf_counter_update(counter
, counter
->ctx
->time
);
2508 static void task_clock_perf_counter_read(struct perf_counter
*counter
)
2513 update_context_time(counter
->ctx
);
2514 time
= counter
->ctx
->time
;
2516 u64 now
= perf_clock();
2517 u64 delta
= now
- counter
->ctx
->timestamp
;
2518 time
= counter
->ctx
->time
+ delta
;
2521 task_clock_perf_counter_update(counter
, time
);
2524 static const struct pmu perf_ops_task_clock
= {
2525 .enable
= task_clock_perf_counter_enable
,
2526 .disable
= task_clock_perf_counter_disable
,
2527 .read
= task_clock_perf_counter_read
,
2531 * Software counter: cpu migrations
2534 static inline u64
get_cpu_migrations(struct perf_counter
*counter
)
2536 struct task_struct
*curr
= counter
->ctx
->task
;
2539 return curr
->se
.nr_migrations
;
2540 return cpu_nr_migrations(smp_processor_id());
2543 static void cpu_migrations_perf_counter_update(struct perf_counter
*counter
)
2548 prev
= atomic64_read(&counter
->hw
.prev_count
);
2549 now
= get_cpu_migrations(counter
);
2551 atomic64_set(&counter
->hw
.prev_count
, now
);
2555 atomic64_add(delta
, &counter
->count
);
2558 static void cpu_migrations_perf_counter_read(struct perf_counter
*counter
)
2560 cpu_migrations_perf_counter_update(counter
);
2563 static int cpu_migrations_perf_counter_enable(struct perf_counter
*counter
)
2565 if (counter
->prev_state
<= PERF_COUNTER_STATE_OFF
)
2566 atomic64_set(&counter
->hw
.prev_count
,
2567 get_cpu_migrations(counter
));
2571 static void cpu_migrations_perf_counter_disable(struct perf_counter
*counter
)
2573 cpu_migrations_perf_counter_update(counter
);
2576 static const struct pmu perf_ops_cpu_migrations
= {
2577 .enable
= cpu_migrations_perf_counter_enable
,
2578 .disable
= cpu_migrations_perf_counter_disable
,
2579 .read
= cpu_migrations_perf_counter_read
,
2582 #ifdef CONFIG_EVENT_PROFILE
2583 void perf_tpcounter_event(int event_id
)
2585 struct pt_regs
*regs
= get_irq_regs();
2588 regs
= task_pt_regs(current
);
2590 __perf_swcounter_event(PERF_TYPE_TRACEPOINT
, event_id
, 1, 1, regs
, 0);
2592 EXPORT_SYMBOL_GPL(perf_tpcounter_event
);
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 pmu
*tp_perf_counter_init(struct perf_counter
*counter
)
2604 int event_id
= perf_event_id(&counter
->hw_event
);
2607 ret
= ftrace_profile_enable(event_id
);
2611 counter
->destroy
= tp_perf_counter_destroy
;
2612 counter
->hw
.irq_period
= counter
->hw_event
.irq_period
;
2614 return &perf_ops_generic
;
2617 static const struct pmu
*tp_perf_counter_init(struct perf_counter
*counter
)
2623 static const struct pmu
*sw_perf_counter_init(struct perf_counter
*counter
)
2625 struct perf_counter_hw_event
*hw_event
= &counter
->hw_event
;
2626 const struct pmu
*pmu
= NULL
;
2627 struct hw_perf_counter
*hwc
= &counter
->hw
;
2630 * Software counters (currently) can't in general distinguish
2631 * between user, kernel and hypervisor events.
2632 * However, context switches and cpu migrations are considered
2633 * to be kernel events, and page faults are never hypervisor
2636 switch (perf_event_id(&counter
->hw_event
)) {
2637 case PERF_COUNT_CPU_CLOCK
:
2638 pmu
= &perf_ops_cpu_clock
;
2640 if (hw_event
->irq_period
&& hw_event
->irq_period
< 10000)
2641 hw_event
->irq_period
= 10000;
2643 case PERF_COUNT_TASK_CLOCK
:
2645 * If the user instantiates this as a per-cpu counter,
2646 * use the cpu_clock counter instead.
2648 if (counter
->ctx
->task
)
2649 pmu
= &perf_ops_task_clock
;
2651 pmu
= &perf_ops_cpu_clock
;
2653 if (hw_event
->irq_period
&& hw_event
->irq_period
< 10000)
2654 hw_event
->irq_period
= 10000;
2656 case PERF_COUNT_PAGE_FAULTS
:
2657 case PERF_COUNT_PAGE_FAULTS_MIN
:
2658 case PERF_COUNT_PAGE_FAULTS_MAJ
:
2659 case PERF_COUNT_CONTEXT_SWITCHES
:
2660 pmu
= &perf_ops_generic
;
2662 case PERF_COUNT_CPU_MIGRATIONS
:
2663 if (!counter
->hw_event
.exclude_kernel
)
2664 pmu
= &perf_ops_cpu_migrations
;
2669 hwc
->irq_period
= hw_event
->irq_period
;
2675 * Allocate and initialize a counter structure
2677 static struct perf_counter
*
2678 perf_counter_alloc(struct perf_counter_hw_event
*hw_event
,
2680 struct perf_counter_context
*ctx
,
2681 struct perf_counter
*group_leader
,
2684 const struct pmu
*pmu
;
2685 struct perf_counter
*counter
;
2688 counter
= kzalloc(sizeof(*counter
), gfpflags
);
2690 return ERR_PTR(-ENOMEM
);
2693 * Single counters are their own group leaders, with an
2694 * empty sibling list:
2697 group_leader
= counter
;
2699 mutex_init(&counter
->mutex
);
2700 INIT_LIST_HEAD(&counter
->list_entry
);
2701 INIT_LIST_HEAD(&counter
->event_entry
);
2702 INIT_LIST_HEAD(&counter
->sibling_list
);
2703 init_waitqueue_head(&counter
->waitq
);
2705 mutex_init(&counter
->mmap_mutex
);
2707 INIT_LIST_HEAD(&counter
->child_list
);
2710 counter
->hw_event
= *hw_event
;
2711 counter
->group_leader
= group_leader
;
2712 counter
->pmu
= NULL
;
2715 counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
2716 if (hw_event
->disabled
)
2717 counter
->state
= PERF_COUNTER_STATE_OFF
;
2721 if (perf_event_raw(hw_event
)) {
2722 pmu
= hw_perf_counter_init(counter
);
2726 switch (perf_event_type(hw_event
)) {
2727 case PERF_TYPE_HARDWARE
:
2728 pmu
= hw_perf_counter_init(counter
);
2731 case PERF_TYPE_SOFTWARE
:
2732 pmu
= sw_perf_counter_init(counter
);
2735 case PERF_TYPE_TRACEPOINT
:
2736 pmu
= tp_perf_counter_init(counter
);
2743 else if (IS_ERR(pmu
))
2748 return ERR_PTR(err
);
2753 if (counter
->hw_event
.mmap
)
2754 atomic_inc(&nr_mmap_tracking
);
2755 if (counter
->hw_event
.munmap
)
2756 atomic_inc(&nr_munmap_tracking
);
2757 if (counter
->hw_event
.comm
)
2758 atomic_inc(&nr_comm_tracking
);
2764 * sys_perf_counter_open - open a performance counter, associate it to a task/cpu
2766 * @hw_event_uptr: event type attributes for monitoring/sampling
2769 * @group_fd: group leader counter fd
2771 SYSCALL_DEFINE5(perf_counter_open
,
2772 const struct perf_counter_hw_event __user
*, hw_event_uptr
,
2773 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
2775 struct perf_counter
*counter
, *group_leader
;
2776 struct perf_counter_hw_event hw_event
;
2777 struct perf_counter_context
*ctx
;
2778 struct file
*counter_file
= NULL
;
2779 struct file
*group_file
= NULL
;
2780 int fput_needed
= 0;
2781 int fput_needed2
= 0;
2784 /* for future expandability... */
2788 if (copy_from_user(&hw_event
, hw_event_uptr
, sizeof(hw_event
)) != 0)
2792 * Get the target context (task or percpu):
2794 ctx
= find_get_context(pid
, cpu
);
2796 return PTR_ERR(ctx
);
2799 * Look up the group leader (we will attach this counter to it):
2801 group_leader
= NULL
;
2802 if (group_fd
!= -1) {
2804 group_file
= fget_light(group_fd
, &fput_needed
);
2806 goto err_put_context
;
2807 if (group_file
->f_op
!= &perf_fops
)
2808 goto err_put_context
;
2810 group_leader
= group_file
->private_data
;
2812 * Do not allow a recursive hierarchy (this new sibling
2813 * becoming part of another group-sibling):
2815 if (group_leader
->group_leader
!= group_leader
)
2816 goto err_put_context
;
2818 * Do not allow to attach to a group in a different
2819 * task or CPU context:
2821 if (group_leader
->ctx
!= ctx
)
2822 goto err_put_context
;
2824 * Only a group leader can be exclusive or pinned
2826 if (hw_event
.exclusive
|| hw_event
.pinned
)
2827 goto err_put_context
;
2830 counter
= perf_counter_alloc(&hw_event
, cpu
, ctx
, group_leader
,
2832 ret
= PTR_ERR(counter
);
2833 if (IS_ERR(counter
))
2834 goto err_put_context
;
2836 ret
= anon_inode_getfd("[perf_counter]", &perf_fops
, counter
, 0);
2838 goto err_free_put_context
;
2840 counter_file
= fget_light(ret
, &fput_needed2
);
2842 goto err_free_put_context
;
2844 counter
->filp
= counter_file
;
2845 mutex_lock(&ctx
->mutex
);
2846 perf_install_in_context(ctx
, counter
, cpu
);
2847 mutex_unlock(&ctx
->mutex
);
2849 fput_light(counter_file
, fput_needed2
);
2852 fput_light(group_file
, fput_needed
);
2856 err_free_put_context
:
2866 * Initialize the perf_counter context in a task_struct:
2869 __perf_counter_init_context(struct perf_counter_context
*ctx
,
2870 struct task_struct
*task
)
2872 memset(ctx
, 0, sizeof(*ctx
));
2873 spin_lock_init(&ctx
->lock
);
2874 mutex_init(&ctx
->mutex
);
2875 INIT_LIST_HEAD(&ctx
->counter_list
);
2876 INIT_LIST_HEAD(&ctx
->event_list
);
2881 * inherit a counter from parent task to child task:
2883 static struct perf_counter
*
2884 inherit_counter(struct perf_counter
*parent_counter
,
2885 struct task_struct
*parent
,
2886 struct perf_counter_context
*parent_ctx
,
2887 struct task_struct
*child
,
2888 struct perf_counter
*group_leader
,
2889 struct perf_counter_context
*child_ctx
)
2891 struct perf_counter
*child_counter
;
2894 * Instead of creating recursive hierarchies of counters,
2895 * we link inherited counters back to the original parent,
2896 * which has a filp for sure, which we use as the reference
2899 if (parent_counter
->parent
)
2900 parent_counter
= parent_counter
->parent
;
2902 child_counter
= perf_counter_alloc(&parent_counter
->hw_event
,
2903 parent_counter
->cpu
, child_ctx
,
2904 group_leader
, GFP_KERNEL
);
2905 if (IS_ERR(child_counter
))
2906 return child_counter
;
2909 * Link it up in the child's context:
2911 child_counter
->task
= child
;
2912 add_counter_to_ctx(child_counter
, child_ctx
);
2914 child_counter
->parent
= parent_counter
;
2916 * inherit into child's child as well:
2918 child_counter
->hw_event
.inherit
= 1;
2921 * Get a reference to the parent filp - we will fput it
2922 * when the child counter exits. This is safe to do because
2923 * we are in the parent and we know that the filp still
2924 * exists and has a nonzero count:
2926 atomic_long_inc(&parent_counter
->filp
->f_count
);
2929 * Link this into the parent counter's child list
2931 mutex_lock(&parent_counter
->mutex
);
2932 list_add_tail(&child_counter
->child_list
, &parent_counter
->child_list
);
2935 * Make the child state follow the state of the parent counter,
2936 * not its hw_event.disabled bit. We hold the parent's mutex,
2937 * so we won't race with perf_counter_{en,dis}able_family.
2939 if (parent_counter
->state
>= PERF_COUNTER_STATE_INACTIVE
)
2940 child_counter
->state
= PERF_COUNTER_STATE_INACTIVE
;
2942 child_counter
->state
= PERF_COUNTER_STATE_OFF
;
2944 mutex_unlock(&parent_counter
->mutex
);
2946 return child_counter
;
2949 static int inherit_group(struct perf_counter
*parent_counter
,
2950 struct task_struct
*parent
,
2951 struct perf_counter_context
*parent_ctx
,
2952 struct task_struct
*child
,
2953 struct perf_counter_context
*child_ctx
)
2955 struct perf_counter
*leader
;
2956 struct perf_counter
*sub
;
2957 struct perf_counter
*child_ctr
;
2959 leader
= inherit_counter(parent_counter
, parent
, parent_ctx
,
2960 child
, NULL
, child_ctx
);
2962 return PTR_ERR(leader
);
2963 list_for_each_entry(sub
, &parent_counter
->sibling_list
, list_entry
) {
2964 child_ctr
= inherit_counter(sub
, parent
, parent_ctx
,
2965 child
, leader
, child_ctx
);
2966 if (IS_ERR(child_ctr
))
2967 return PTR_ERR(child_ctr
);
2972 static void sync_child_counter(struct perf_counter
*child_counter
,
2973 struct perf_counter
*parent_counter
)
2975 u64 parent_val
, child_val
;
2977 parent_val
= atomic64_read(&parent_counter
->count
);
2978 child_val
= atomic64_read(&child_counter
->count
);
2981 * Add back the child's count to the parent's count:
2983 atomic64_add(child_val
, &parent_counter
->count
);
2984 atomic64_add(child_counter
->total_time_enabled
,
2985 &parent_counter
->child_total_time_enabled
);
2986 atomic64_add(child_counter
->total_time_running
,
2987 &parent_counter
->child_total_time_running
);
2990 * Remove this counter from the parent's list
2992 mutex_lock(&parent_counter
->mutex
);
2993 list_del_init(&child_counter
->child_list
);
2994 mutex_unlock(&parent_counter
->mutex
);
2997 * Release the parent counter, if this was the last
3000 fput(parent_counter
->filp
);
3004 __perf_counter_exit_task(struct task_struct
*child
,
3005 struct perf_counter
*child_counter
,
3006 struct perf_counter_context
*child_ctx
)
3008 struct perf_counter
*parent_counter
;
3009 struct perf_counter
*sub
, *tmp
;
3012 * If we do not self-reap then we have to wait for the
3013 * child task to unschedule (it will happen for sure),
3014 * so that its counter is at its final count. (This
3015 * condition triggers rarely - child tasks usually get
3016 * off their CPU before the parent has a chance to
3017 * get this far into the reaping action)
3019 if (child
!= current
) {
3020 wait_task_inactive(child
, 0);
3021 list_del_init(&child_counter
->list_entry
);
3022 update_counter_times(child_counter
);
3024 struct perf_cpu_context
*cpuctx
;
3025 unsigned long flags
;
3029 * Disable and unlink this counter.
3031 * Be careful about zapping the list - IRQ/NMI context
3032 * could still be processing it:
3034 local_irq_save(flags
);
3035 perf_flags
= hw_perf_save_disable();
3037 cpuctx
= &__get_cpu_var(perf_cpu_context
);
3039 group_sched_out(child_counter
, cpuctx
, child_ctx
);
3040 update_counter_times(child_counter
);
3042 list_del_init(&child_counter
->list_entry
);
3044 child_ctx
->nr_counters
--;
3046 hw_perf_restore(perf_flags
);
3047 local_irq_restore(flags
);
3050 parent_counter
= child_counter
->parent
;
3052 * It can happen that parent exits first, and has counters
3053 * that are still around due to the child reference. These
3054 * counters need to be zapped - but otherwise linger.
3056 if (parent_counter
) {
3057 sync_child_counter(child_counter
, parent_counter
);
3058 list_for_each_entry_safe(sub
, tmp
, &child_counter
->sibling_list
,
3061 sync_child_counter(sub
, sub
->parent
);
3065 free_counter(child_counter
);
3070 * When a child task exits, feed back counter values to parent counters.
3072 * Note: we may be running in child context, but the PID is not hashed
3073 * anymore so new counters will not be added.
3075 void perf_counter_exit_task(struct task_struct
*child
)
3077 struct perf_counter
*child_counter
, *tmp
;
3078 struct perf_counter_context
*child_ctx
;
3080 child_ctx
= &child
->perf_counter_ctx
;
3082 if (likely(!child_ctx
->nr_counters
))
3085 list_for_each_entry_safe(child_counter
, tmp
, &child_ctx
->counter_list
,
3087 __perf_counter_exit_task(child
, child_counter
, child_ctx
);
3091 * Initialize the perf_counter context in task_struct
3093 void perf_counter_init_task(struct task_struct
*child
)
3095 struct perf_counter_context
*child_ctx
, *parent_ctx
;
3096 struct perf_counter
*counter
;
3097 struct task_struct
*parent
= current
;
3099 child_ctx
= &child
->perf_counter_ctx
;
3100 parent_ctx
= &parent
->perf_counter_ctx
;
3102 __perf_counter_init_context(child_ctx
, child
);
3105 * This is executed from the parent task context, so inherit
3106 * counters that have been marked for cloning:
3109 if (likely(!parent_ctx
->nr_counters
))
3113 * Lock the parent list. No need to lock the child - not PID
3114 * hashed yet and not running, so nobody can access it.
3116 mutex_lock(&parent_ctx
->mutex
);
3119 * We dont have to disable NMIs - we are only looking at
3120 * the list, not manipulating it:
3122 list_for_each_entry(counter
, &parent_ctx
->counter_list
, list_entry
) {
3123 if (!counter
->hw_event
.inherit
)
3126 if (inherit_group(counter
, parent
,
3127 parent_ctx
, child
, child_ctx
))
3131 mutex_unlock(&parent_ctx
->mutex
);
3134 static void __cpuinit
perf_counter_init_cpu(int cpu
)
3136 struct perf_cpu_context
*cpuctx
;
3138 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3139 __perf_counter_init_context(&cpuctx
->ctx
, NULL
);
3141 mutex_lock(&perf_resource_mutex
);
3142 cpuctx
->max_pertask
= perf_max_counters
- perf_reserved_percpu
;
3143 mutex_unlock(&perf_resource_mutex
);
3145 hw_perf_counter_setup(cpu
);
3148 #ifdef CONFIG_HOTPLUG_CPU
3149 static void __perf_counter_exit_cpu(void *info
)
3151 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
3152 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3153 struct perf_counter
*counter
, *tmp
;
3155 list_for_each_entry_safe(counter
, tmp
, &ctx
->counter_list
, list_entry
)
3156 __perf_counter_remove_from_context(counter
);
3158 static void perf_counter_exit_cpu(int cpu
)
3160 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3161 struct perf_counter_context
*ctx
= &cpuctx
->ctx
;
3163 mutex_lock(&ctx
->mutex
);
3164 smp_call_function_single(cpu
, __perf_counter_exit_cpu
, NULL
, 1);
3165 mutex_unlock(&ctx
->mutex
);
3168 static inline void perf_counter_exit_cpu(int cpu
) { }
3171 static int __cpuinit
3172 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
3174 unsigned int cpu
= (long)hcpu
;
3178 case CPU_UP_PREPARE
:
3179 case CPU_UP_PREPARE_FROZEN
:
3180 perf_counter_init_cpu(cpu
);
3183 case CPU_DOWN_PREPARE
:
3184 case CPU_DOWN_PREPARE_FROZEN
:
3185 perf_counter_exit_cpu(cpu
);
3195 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
3196 .notifier_call
= perf_cpu_notify
,
3199 static int __init
perf_counter_init(void)
3201 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
3202 (void *)(long)smp_processor_id());
3203 register_cpu_notifier(&perf_cpu_nb
);
3207 early_initcall(perf_counter_init
);
3209 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class, char *buf
)
3211 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
3215 perf_set_reserve_percpu(struct sysdev_class
*class,
3219 struct perf_cpu_context
*cpuctx
;
3223 err
= strict_strtoul(buf
, 10, &val
);
3226 if (val
> perf_max_counters
)
3229 mutex_lock(&perf_resource_mutex
);
3230 perf_reserved_percpu
= val
;
3231 for_each_online_cpu(cpu
) {
3232 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
3233 spin_lock_irq(&cpuctx
->ctx
.lock
);
3234 mpt
= min(perf_max_counters
- cpuctx
->ctx
.nr_counters
,
3235 perf_max_counters
- perf_reserved_percpu
);
3236 cpuctx
->max_pertask
= mpt
;
3237 spin_unlock_irq(&cpuctx
->ctx
.lock
);
3239 mutex_unlock(&perf_resource_mutex
);
3244 static ssize_t
perf_show_overcommit(struct sysdev_class
*class, char *buf
)
3246 return sprintf(buf
, "%d\n", perf_overcommit
);
3250 perf_set_overcommit(struct sysdev_class
*class, const char *buf
, size_t count
)
3255 err
= strict_strtoul(buf
, 10, &val
);
3261 mutex_lock(&perf_resource_mutex
);
3262 perf_overcommit
= val
;
3263 mutex_unlock(&perf_resource_mutex
);
3268 static SYSDEV_CLASS_ATTR(
3271 perf_show_reserve_percpu
,
3272 perf_set_reserve_percpu
3275 static SYSDEV_CLASS_ATTR(
3278 perf_show_overcommit
,
3282 static struct attribute
*perfclass_attrs
[] = {
3283 &attr_reserve_percpu
.attr
,
3284 &attr_overcommit
.attr
,
3288 static struct attribute_group perfclass_attr_group
= {
3289 .attrs
= perfclass_attrs
,
3290 .name
= "perf_counters",
3293 static int __init
perf_counter_sysfs_init(void)
3295 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
3296 &perfclass_attr_group
);
3298 device_initcall(perf_counter_sysfs_init
);