Commit-ID: ec89a06fd4e12301f11ab039ee07d2353a18addc Gitweb: http://git.kernel.org/tip/ec89a06fd4e12301f11ab039ee07d2353a18addc Author: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx> AuthorDate: Wed, 9 Dec 2009 11:30:36 +0800 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Wed, 9 Dec 2009 09:56:27 +0100 perf_event: Cleanup for cpu_clock_perf_event_update() Using atomic64_xchg() instead of atomic64_read() and atomic64_set(). Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx> Reviewed-by: Frederic Weisbecker <fweisbec@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> LKML-Reference: <4B1F19DC.90204@xxxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- 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 77641ae..94e1b28 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); } -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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