Re: [PATCH v4] sched/fair: Introduce SIS_UTIL to search idle CPU based on sum of util_avg

[Peter Zijlstra]

On Wed, Jun 22, 2022 at 12:06:55PM +0530, K Prateek Nayak wrote:
> Hello Chenyu,
> 
> I'm sorry for the delay. The testing took a while but below are
> the results from testing on our system.
> 
> tl;dr
> 
> o We ran all the tests with with SIS_PROP disabled.
> o tbench reaches close to saturation early with 256 clients.
> o schbench shows improvements for low worker counts.
> o All other benchmark results seem comparable to tip.
>   We don't see any serious regressions with v4.
> 
> > @@ -61,6 +61,7 @@ SCHED_FEAT(TTWU_QUEUE, true)
> >   * When doing wakeups, attempt to limit superfluous scans of the LLC domain.
> >   */
> >  SCHED_FEAT(SIS_PROP, true)
> 
> SIS_PROP was disabled in our testing as follows:
> 
> --
> -SCHED_FEAT(SIS_PROP, true)
> +SCHED_FEAT(SIS_PROP, false)

So how about I make this change.

> With v4 on the current tip, I don't see any need for
> a special case for systems with smaller LLCs with
> SIS_PROP disabled and SIS_UITL enable. Even SIS Efficiency
> seems to be better with SIS_UTIL for hackbench.
> 
> Tested-by: K Prateek Nayak <kprateek.nayak@xxxxxxx> 

And apply this thing, lets see how it fares..