Re: [PATCH RFC] sched/fair: Avoid unnecessary IPIs for ILB

From: Vineeth Pillai
Date: Fri Oct 06 2023 - 17:20:58 EST


Hi Shrikanth,

> Hi Joel/Vineeth.
>
> Its an interesting patch.
>
> Gave this patch a try on powerpc system with 96 CPU. (12 cores SMT8)
> Was debugging an issue where ILB count goes up significantly at a specific
> busy CPU count. Haven't yet found out why. Its WIP. Was curious if this patch
> would address that issue.
>
Increased SCHED_SOFTIRQ was another problem that we noticed and we
have a separate fix for that in the chromeos tree. We were planning to
send the patch after a bit more testing. You could try the patch and
see if it solves the problem that you are seeing:
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/918f229ba2ff720f5dfae4768469acbb6ea39fe2

Thanks