On Mon, Apr 23, 2018 at 05:41:16PM -0700, subhra mazumdar wrote:
> Lower the lower limit of idle cpu search in select_idle_cpu() and also put
> an upper limit. This helps in scalability of the search by restricting the
> search window.
> @@ -6297,15 +6297,24 @@ static int select_idle_cpu(struct task_struct *p,
> struct sched_domain *sd, int t
>
> if (sched_feat(SIS_PROP)) {
> u64 span_avg = sd->span_weight * avg_idle;
> - if (span_avg > 4*avg_cost)
> + if (span_avg > 2*avg_cost) {
> nr = div_u64(span_avg, avg_cost);
> - else
> - nr = 4;
> + if (nr > 4)
> + nr = 4;
> + } else {
> + nr = 2;
> + }
> }
Why do you need to put a max on? Why isn't the proportional thing
working as is? (is the average no good because of big variance or what)
Again, why do you need to lower the min; what's wrong with 4?
The reason I picked 4 is that many laptops have 4 CPUs and desktops
really want to avoid queueing if at all possible.
