Messages in this thread Patch in this message | | | Date | Wed, 09 Dec 2009 11:30:36 +0800 | From | Xiao Guangrong <> | Subject | [PATCH 3/3] perf_event: cleanup for cpu_clock_perf_event_update() |
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Using atomic64_xchg() instead of atomic64_read() and atomic64_set().
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> --- kernel/perf_event.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 592b293..8f46012 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4079,8 +4079,7 @@ static void cpu_clock_perf_event_update(struct perf_event *event) u64 now; now = cpu_clock(cpu); - prev = atomic64_read(&event->hw.prev_count); - atomic64_set(&event->hw.prev_count, now); + prev = atomic64_xchg(&event->hw.prev_count, now); atomic64_add(now - prev, &event->count); } -- 1.6.1.2
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