On Tue, Sep 19, 2017 at 11:09:32PM -0700, Yonghong Song wrote:
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 3e691b7..2d5bbe5 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -3684,10 +3684,12 @@ static inline u64 perf_event_count(struct perf_event
> *event)
> * will not be local and we cannot read them atomically
> * - must not have a pmu::count method
> */
> -int perf_event_read_local(struct perf_event *event, u64 *value)
> +int perf_event_read_local(struct perf_event *event, u64 *value,
> + u64 *enabled, u64 *running)
> {
> unsigned long flags;
> int ret = 0;
> + u64 now;
>
> /*
> * Disabling interrupts avoids all counter scheduling (context
> @@ -3718,14 +3720,21 @@ int perf_event_read_local(struct perf_event *event,
> u64 *value)
> goto out;
> }
>
> + now = event->shadow_ctx_time + perf_clock();
> + if (enabled)
> + *enabled = now - event->tstamp_enabled;
> /*
> * If the event is currently on this CPU, its either a per-task event,
> * or local to this CPU. Furthermore it means its ACTIVE (otherwise
> * oncpu == -1).
> */
> - if (event->oncpu == smp_processor_id())
> + if (event->oncpu == smp_processor_id()) {
> event->pmu->read(event);
> -
> + if (running)
> + *running = now - event->tstamp_running;
> + } else if (running) {
> + *running = event->total_time_running;
> + }
> *value = local64_read(&event->count);
> out:
> local_irq_restore(flags);
Yeah, this looks about right.
Dave, could we have this in a topic tree of sorts, because I have a
pending series to rework all the timekeeping and it might be nice to not
have sfr run into all sorts of conflicts.
