[PATCH 2/4] perf: Add perf_event_count()

Peter Zijlstra
2010-05-21T14:20:57Z

[-- Attachment #1: perf-event_count.patch --]
[-- Type: text/plain, Size: 2456 bytes --]

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

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
kernel/perf_event.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -1701,6 +1701,11 @@ 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)
{
/*
@@ -1720,7 +1725,7 @@ static u64 perf_event_read(struct perf_e
raw_spin_unlock_irqrestore(&ctx->lock, flags);
}

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

/*
@@ -2280,7 +2285,7 @@ void perf_event_update_userpage(struct p
++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);

@@ -3125,7 +3130,7 @@ static void perf_output_read_one(struct
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);
@@ -3162,7 +3167,7 @@ static void perf_output_read_group(struc
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);

@@ -3174,7 +3179,7 @@ static void perf_output_read_group(struc
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);

@@ -5272,7 +5277,7 @@ static void sync_child_event(struct perf
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: