Re: [PATCH 4/5] sched/fair: Add SIS_UTIL support to select_idle_capacity()

[K Prateek Nayak]

Hello Andrea,

On 4/23/2026 1:06 PM, Andrea Righi wrote:
> From: K Prateek Nayak <kprateek.nayak@xxxxxxx>
> 
> Add to select_idle_capacity() the same SIS_UTIL-controlled idle-scan
> mechanism, already used by select_idle_cpu(): when sched_feat(SIS_UTIL)
> is enabled and the LLC domain has sched_domain_shared data, derive the
> per-attempt scan limit from sd->shared->nr_idle_scan.
> 
> That bounds the walk on large LLCs and allows an early return once the
> scan limit is reached, if we already picked a sufficiently strong
> idle-core candidate (best_fits == -4).
> 
> Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>

I think this still requires your S-o-b ;-)

Thank you again for cleaning this up and testing it. Since you mentioned
having tested on Grace without SMT, I don't think this will be a problem
for other CAS use cases too although I'll love to hear if Android with
overloaded status could run into any problems when that state is
triggered.

-- 
Thanks and Regards,
Prateek