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perf_events: Fix __perf_event_exit_task() vs. update_event_times() locking 

Move the update_event_times() call in __perf_event_exit_task()
into list_del_event() because that holds the proper lock
(ctx->lock) and seems a more natural place to do the last time
update.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091123103819.842455480@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Peter Zijlstra 2009-11-23 11:37:27 +01:00 committed by Ingo Molnar
parent 5e942bb333
commit f67218c3e9
1 changed files with 39 additions and 39 deletions
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78
kernel/perf_event.c
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@ -246,6 +246,44 @@ static void perf_unpin_context(struct perf_event_context *ctx)
put_ctx(ctx);
}
static inline u64 perf_clock(void)
{
return cpu_clock(smp_processor_id());
}
/*
* Update the record of the current time in a context.
*/
static void update_context_time(struct perf_event_context *ctx)
{
u64 now = perf_clock();
ctx->time += now - ctx->timestamp;
ctx->timestamp = now;
}
/*
* Update the total_time_enabled and total_time_running fields for a event.
*/
static void update_event_times(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
u64 run_end;
if (event->state < PERF_EVENT_STATE_INACTIVE ||
event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
return;
event->total_time_enabled = ctx->time - event->tstamp_enabled;
if (event->state == PERF_EVENT_STATE_INACTIVE)
run_end = event->tstamp_stopped;
else
run_end = ctx->time;
event->total_time_running = run_end - event->tstamp_running;
}
/*
* Add a event from the lists for its context.
* Must be called with ctx->mutex and ctx->lock held.
@ -294,6 +332,7 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
if (event->group_leader != event)
event->group_leader->nr_siblings--;
update_event_times(event);
event->state = PERF_EVENT_STATE_OFF;
/*
@ -454,44 +493,6 @@ retry:
spin_unlock_irq(&ctx->lock);
}
static inline u64 perf_clock(void)
{
return cpu_clock(smp_processor_id());
}
/*
* Update the record of the current time in a context.
*/
static void update_context_time(struct perf_event_context *ctx)
{
u64 now = perf_clock();
ctx->time += now - ctx->timestamp;
ctx->timestamp = now;
}
/*
* Update the total_time_enabled and total_time_running fields for a event.
*/
static void update_event_times(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
u64 run_end;
if (event->state < PERF_EVENT_STATE_INACTIVE ||
event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
return;
event->total_time_enabled = ctx->time - event->tstamp_enabled;
if (event->state == PERF_EVENT_STATE_INACTIVE)
run_end = event->tstamp_stopped;
else
run_end = ctx->time;
event->total_time_running = run_end - event->tstamp_running;
}
/*
* Update total_time_enabled and total_time_running for all events in a group.
*/
@ -4931,7 +4932,6 @@ __perf_event_exit_task(struct perf_event *child_event,
{
struct perf_event *parent_event;
update_event_times(child_event);
perf_event_remove_from_context(child_event);
parent_event = child_event->parent;