diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2e6d95f97419..9e7012689a84 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -471,8 +471,8 @@ struct hw_perf_event { unsigned long event_base; int idx; }; - union { /* software */ - atomic64_t count; + struct { /* software */ + s64 remaining; struct hrtimer hrtimer; }; }; diff --git a/kernel/perf_event.c b/kernel/perf_event.c index afb7ef3dbc44..33ff019f9aa6 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3969,6 +3969,42 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) return ret; } +static void perf_swevent_start_hrtimer(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + + hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hwc->hrtimer.function = perf_swevent_hrtimer; + if (hwc->sample_period) { + u64 period; + + if (hwc->remaining) { + if (hwc->remaining < 0) + period = 10000; + else + period = hwc->remaining; + hwc->remaining = 0; + } else { + period = max_t(u64, 10000, hwc->sample_period); + } + __hrtimer_start_range_ns(&hwc->hrtimer, + ns_to_ktime(period), 0, + HRTIMER_MODE_REL, 0); + } +} + +static void perf_swevent_cancel_hrtimer(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + + if (hwc->sample_period) { + ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer); + hwc->remaining = ktime_to_ns(remaining); + + hrtimer_cancel(&hwc->hrtimer); + } +} + /* * Software event: cpu wall time clock */ @@ -3991,22 +4027,14 @@ static int cpu_clock_perf_event_enable(struct perf_event *event) int cpu = raw_smp_processor_id(); atomic64_set(&hwc->prev_count, cpu_clock(cpu)); - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hwc->hrtimer.function = perf_swevent_hrtimer; - if (hwc->sample_period) { - u64 period = max_t(u64, 10000, hwc->sample_period); - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL, 0); - } + perf_swevent_start_hrtimer(event); return 0; } static void cpu_clock_perf_event_disable(struct perf_event *event) { - if (event->hw.sample_period) - hrtimer_cancel(&event->hw.hrtimer); + perf_swevent_cancel_hrtimer(event); cpu_clock_perf_event_update(event); } @@ -4043,22 +4071,15 @@ static int task_clock_perf_event_enable(struct perf_event *event) now = event->ctx->time; atomic64_set(&hwc->prev_count, now); - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hwc->hrtimer.function = perf_swevent_hrtimer; - if (hwc->sample_period) { - u64 period = max_t(u64, 10000, hwc->sample_period); - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL, 0); - } + + perf_swevent_start_hrtimer(event); return 0; } static void task_clock_perf_event_disable(struct perf_event *event) { - if (event->hw.sample_period) - hrtimer_cancel(&event->hw.hrtimer); + perf_swevent_cancel_hrtimer(event); task_clock_perf_event_update(event, event->ctx->time); }