[tip:perf/core] perf: Add perf_event_count()

tip-bot for Peter Zijlstra
2010-06-09T10:17:58Z

Commit-ID: b5e58793c7a8ec35e72ea6ec6c353499dd189809
Gitweb: http://git.kernel.org/tip/b5e58793c7a8ec35e72ea6ec6c353499dd189809
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 21 May 2010 14:43:12 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 9 Jun 2010 11:12:36 +0200

perf: Add perf_event_count()

Create a helper function for those sites that want to read the event count.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/perf_event.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index f75c9c9..ab4c0ff 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1736,6 +1736,11 @@ static void __perf_event_read(void *info)
event->pmu->read(event);
}

+static inline u64 perf_event_count(struct perf_event *event)
+{
+ return atomic64_read(&event->count);
+}
+
static u64 perf_event_read(struct perf_event *event)
{
/*
@@ -1755,7 +1760,7 @@ static u64 perf_event_read(struct perf_event *event)
raw_spin_unlock_irqrestore(&ctx->lock, flags);
}

- return atomic64_read(&event->count);
+ return perf_event_count(event);
}

/*
@@ -2352,7 +2357,7 @@ void perf_event_update_userpage(struct perf_event *event)
++userpg->lock;
barrier();
userpg->index = perf_event_index(event);
- userpg->offset = atomic64_read(&event->count);
+ userpg->offset = perf_event_count(event);
if (event->state == PERF_EVENT_STATE_ACTIVE)
userpg->offset -= atomic64_read(&event->hw.prev_count);

@@ -3211,7 +3216,7 @@ static void perf_output_read_one(struct perf_output_handle *handle,
u64 values[4];
int n = 0;

- values[n++] = atomic64_read(&event->count);
+ values[n++] = perf_event_count(event);
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
values[n++] = event->total_time_enabled +
atomic64_read(&event->child_total_time_enabled);
@@ -3248,7 +3253,7 @@ static void perf_output_read_group(struct perf_output_handle *handle,
if (leader != event)
leader->pmu->read(leader);

- values[n++] = atomic64_read(&leader->count);
+ values[n++] = perf_event_count(leader);
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_event_id(leader);

@@ -3260,7 +3265,7 @@ static void perf_output_read_group(struct perf_output_handle *handle,
if (sub != event)
sub->pmu->read(sub);

- values[n++] = atomic64_read(&sub->count);
+ values[n++] = perf_event_count(sub);
if (read_format & PERF_FORMAT_ID)
values[n++] = primary_event_id(sub);

@@ -5369,7 +5374,7 @@ static void sync_child_event(struct perf_event *child_event,
if (child_event->attr.inherit_stat)
perf_event_read_event(child_event, child);

- child_val = atomic64_read(&child_event->count);
+ child_val = perf_event_count(child_event);

/*
* Add back the child's count to the parent's count: