Re: [PATCH] perf_events: improve x86 event scheduling

[Frederic Weisbecker <fweisbec@gmail.com>]

On Sun, Jan 17, 2010 at 03:42:16PM +0100, Stephane Eranian wrote:
> Frederic,
> 
> 
> Here is what I have now in the x86 code.
> 
> As for your comment on disabling the x86 event, we don't
> need to do this because it is not actually activated yet when
> we return from hw_perf_group_sched_in(). Activation occurs
> really in hw_perf_enable().


Ah, indeed.


> 
> 
> static int x86_event_sched_in(struct perf_event *event,
>                           struct perf_cpu_context *cpuctx, int cpu)
> {
>         int ret = 0;
> 
>         event->state = PERF_EVENT_STATE_ACTIVE;
>         event->oncpu = cpu;
>         event->tstamp_running += event->ctx->time - event->tstamp_stopped;
> 
>         if (is_software_event(event))
>                 ret = event->pmu->enable(event);
> 
>         if (!ret && !is_software_event(event))
>                 cpuctx->active_oncpu++;
> 
>         if (!ret && event->attr.exclusive)
>                 cpuctx->exclusive = 1;
> 
>         return ret;
> }
> 
> static void x86_event_sched_out(struct perf_event *event,
>                             struct perf_cpu_context *cpuctx, int cpu)
> {
>         event->state = PERF_EVENT_STATE_INACTIVE;
>         event->oncpu = -1;
> 
>         event->tstamp_running -= event->ctx->time - event->tstamp_stopped;
> 
>         if (is_software_event(event))
>                 event->pmu->disable(event);
> 
>         if (!is_software_event(event))
>                 cpuctx->active_oncpu--;
> 
>         if (event->attr.exclusive || !cpuctx->active_oncpu)
>                 cpuctx->exclusive = 0;
> }



Yeah looks good.

Thanks.