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authorFranck Bui-Huu <fbuihuu@gmail.com>2010-11-23 16:21:45 +0100
committerIngo Molnar <mingo@elte.hu>2010-11-26 15:14:55 +0100
commit5d508e820a23d9b6e8a149dfaa8ba5cbedf3d95c (patch)
treef11741710e4a2bb6b5c50e0d0b8c8cea0e6d9d6d /kernel/perf_event.c
parent2e939d1da9b5628642314c1e68b4319e61263c94 (diff)
downloadlinux-5d508e820a23d9b6e8a149dfaa8ba5cbedf3d95c.tar.gz
perf: Don't bother to init the hrtimer for no SW sampling counters
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290525705-6265-3-git-send-email-fbuihuu@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r--kernel/perf_event.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 027c4d33b4d3..98c5549c8e29 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4917,24 +4917,26 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
 static void perf_swevent_start_hrtimer(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
+	s64 period;
+
+	if (!is_sampling_event(event))
+		return;
 
 	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hwc->hrtimer.function = perf_swevent_hrtimer;
-	if (is_sampling_event(event)) {
-		s64 period = local64_read(&hwc->period_left);
 
-		if (period) {
-			if (period < 0)
-				period = 10000;
+	period = local64_read(&hwc->period_left);
+	if (period) {
+		if (period < 0)
+			period = 10000;
 
-			local64_set(&hwc->period_left, 0);
-		} else {
-			period = max_t(u64, 10000, hwc->sample_period);
-		}
-		__hrtimer_start_range_ns(&hwc->hrtimer,
+		local64_set(&hwc->period_left, 0);
+	} else {
+		period = max_t(u64, 10000, hwc->sample_period);
+	}
+	__hrtimer_start_range_ns(&hwc->hrtimer,
 				ns_to_ktime(period), 0,
 				HRTIMER_MODE_REL_PINNED, 0);
-	}
 }
 
 static void perf_swevent_cancel_hrtimer(struct perf_event *event)