Re: [PATCH 1/3] sched/fair: Fix statistics for find_idlest_group()

From: Mel Gorman
Date: Tue Mar 03 2020 - 06:44:50 EST


On Tue, Mar 03, 2020 at 12:14:07PM +0100, Vincent Guittot wrote:
> Hi Mel,
>
> On Tue, 3 Mar 2020 at 12:03, Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > From: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> >
> > From: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> >
> > sgs->group_weight is not set while gathering statistics in
> > update_sg_wakeup_stats(). This means that a group can be classified as
> > fully busy with 0 running tasks if utilization is high enough.
> >
> > This path is mainly used for fork and exec.
> >
> > Fixes: 57abff067a08 ("sched/fair: Rework find_idlest_group()")
> > Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
> > Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> > Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> > Link: https://lore.kernel.org/r/20200218144534.4564-1-vincent.guittot@xxxxxxxxxx
>
> This one has been merged in tip/sched/urgent
>

I know and it appears in next but not in mainline yet. As tip/sched/core
is the development baseline for scheduler patches, it should have the
patch -- most likely via mainline to preserve git history. By including
it here, I wanted to highlight that anyone working on tip/sched/core at
the moment should include the patch if they want to avoid invalidating
any test results.

--
Mel Gorman
SUSE Labs