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

From: Vincent Guittot
Date: Tue Mar 03 2020 - 08:12:08 EST


On Tue, 3 Mar 2020 at 12:44, Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> wrote:
>
> 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.

ok. Make sense

>
> --
> Mel Gorman
> SUSE Labs