Re: [PATCH] sched/fair: Ensure _sum and _avg values stay consistent

From: Sachin Sant
Date: Thu Jul 01 2021 - 07:51:15 EST




> On 01-Jul-2021, at 4:39 PM, Odin Ugedal <odin@xxxxxxx> wrote:
>
> tor. 1. jul. 2021 kl. 12:34 skrev Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>:
>>
>> What was HEAD when you checked this? 1c35b07e6d39 was merged in the
>> 5.14-rc1 merge window so would not be in 5.13.
>
> From the kernel log it looks like he used commit dbe69e433722
> (somewhere in Linus' tree), and that should include my patch. I don't
> think the patches from Vincent in the previous thread have been posted
> properly, and I think those can fix the edge case you are seeing.
>
Sorry about the confusion. Yes I am using this code level.

commit dbe69e43372212527abf48609aba7fc39a6daa27 (HEAD -> master, origin/master, origin/HEAD)
Merge: a6eaf3850cb1 b6df00789e28
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Wed Jun 30 15:51:09 2021 -0700

This does contain the patch from Odin.

> This should mitigate some issues:
> https://lore.kernel.org/lkml/20210622143154.GA804@vingu-book/
>
> while
> https://lore.kernel.org/lkml/20210623071935.GA29143@vingu-book/
> might also help in some cases as well.
>
> Both of those are needed to make sure that *_avg is zero whenever *_sum is zero.

Okay, so additional patches are required to fix this problem completely.
I can help test these.

Thanks
-Sachin