Re: [PATCH v4 2/2] sched/fair: update scale invariance of PELT

From: Peter Zijlstra
Date: Tue Oct 23 2018 - 06:01:19 EST


On Fri, Oct 19, 2018 at 06:17:51PM +0200, Vincent Guittot wrote:
> In order to achieve this time scaling, a new clock_pelt is created per rq.


> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index 3990818..d987f50 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -848,6 +848,8 @@ struct rq {
> unsigned int clock_update_flags;
> u64 clock;
> u64 clock_task;
> + u64 clock_pelt;
> + unsigned long lost_idle_time;

Very clever that. Seems to work out nicely. We should maybe look at
ensuring all these clock fields are indeed on the same cacheline.