From 5d508e820a23d9b6e8a149dfaa8ba5cbedf3d95c Mon Sep 17 00:00:00 2001 From: Franck Bui-Huu Date: Tue, 23 Nov 2010 16:21:45 +0100 Subject: [PATCH] perf: Don't bother to init the hrtimer for no SW sampling counters Signed-off-by: Franck Bui-Huu Signed-off-by: Peter Zijlstra LKML-Reference: <1290525705-6265-3-git-send-email-fbuihuu@gmail.com> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 24 +++++++++++++----------- 1 file 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) -- 2.20.1