Re: [GIT PULL] scheduler changes for v5.5

Linus Torvalds
2019-11-25T16:49:10Z

On Mon, Nov 25, 2019 at 5:49 AM Valentin Schneider
<valentin.schneider@arm.com> wrote:
>
> On 25/11/2019 12:59, Ingo Molnar wrote:
>
> So I really don't want to be labeled as "that annoying scheduler PR guy",
> but some patches in Vincent's rework should be squashed to avoid being
> performance bisection honeypots.
>
> > Vincent Guittot (14):
> > sched/fair: Remove meaningless imbalance calculation
> > sched/fair: Rework load_balance()
>
> These two ^ (were split for ease of reviewing, [1])
>
> > sched/fair: Rework find_idlest_group()
> > sched/fair: Fix rework of find_idlest_group()
>
> And these two ^ (Mel voiced similar concerns at [2])

If they were split for ease of reviewing, then they should be split in
the history too.

I worry a lot less about some possible (temporary!) performance dip
than about a hard bug, and if the code is easier to review in two
steps then it's going to be easier to find the bug in two steps too.

Linus