Re: [PATCH v4 08/20] sched/fair: load balance only among preferred CPUs

[Shrikanth Hegde]

Hi Prateek, thanks for going through the patches.

On 6/18/26 8:33 AM, K Prateek Nayak wrote:
> Hello Shrikanth,
>
> On 6/17/2026 11:11 PM, Shrikanth Hegde wrote:
> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> > index d78467ec6ee1..3f3c7f0ca489 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -13291,6 +13291,9 @@ static int sched_balance_rq(int this_cpu, struct rq *this_rq,
> >   
> >   	cpumask_and(cpus, sched_domain_span(sd), cpu_active_mask);
> >   
> > +	/* Spread load among preferred CPUs */
> > +	cpumask_and(cpus, cpus, cpu_preferred_mask);
>
> Since "cpu_preferred_mask" is a subset of "cpu_active_mask", just:
>
>      cpumask_and(cpus, sched_domain_span(sd), cpu_preferred_mask);
>
> is sufficient. We don't need that redundant cpumask_and() with
> cpu_active_mask before.

Ack.

> > +
> >   	schedstat_inc(sd->lb_count[idle]);
> >   
> >   redo: