From 01add3eaf1b25e497b14ca210f3bfe5f5dd2b112 Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Thu, 3 Sep 2015 20:07:46 -0700 Subject: perf/core: Split perf_event_read() and perf_event_count() perf_event_read() does two things: - call the PMU to read/update the counter value, and - compute the total count of the event and its children Not all callers need both. perf_event_reset() for instance needs the first piece but doesn't need the second. Similarly, when we implement the ability to read a group of events using the transaction interface, we would need the two pieces done independently. Break up perf_event_read() and have it just read/update the counter and have the callers compute the total count if necessary. Signed-off-by: Sukadev Bhattiprolu Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Michael Ellerman Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Link: http://lkml.kernel.org/r/1441336073-22750-4-git-send-email-sukadev@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- kernel/events/core.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'kernel/events/core.c') diff --git a/kernel/events/core.c b/kernel/events/core.c index c80cee82959f..260bf8cfed51 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3275,7 +3275,7 @@ u64 perf_event_read_local(struct perf_event *event) return val; } -static u64 perf_event_read(struct perf_event *event) +static void perf_event_read(struct perf_event *event) { /* * If event is enabled and currently active on a CPU, update the @@ -3301,8 +3301,6 @@ static u64 perf_event_read(struct perf_event *event) update_event_times(event); raw_spin_unlock_irqrestore(&ctx->lock, flags); } - - return perf_event_count(event); } /* @@ -3818,14 +3816,18 @@ u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running) *running = 0; mutex_lock(&event->child_mutex); - total += perf_event_read(event); + + perf_event_read(event); + total += perf_event_count(event); + *enabled += event->total_time_enabled + atomic64_read(&event->child_total_time_enabled); *running += event->total_time_running + atomic64_read(&event->child_total_time_running); list_for_each_entry(child, &event->child_list, child_list) { - total += perf_event_read(child); + perf_event_read(child); + total += perf_event_count(child); *enabled += child->total_time_enabled; *running += child->total_time_running; } @@ -3985,7 +3987,7 @@ static unsigned int perf_poll(struct file *file, poll_table *wait) static void _perf_event_reset(struct perf_event *event) { - (void)perf_event_read(event); + perf_event_read(event); local64_set(&event->count, 0); perf_event_update_userpage(event); } -- cgit v1.2.3