Re: [PATCH] sched/fair: Update min_vruntime for reweight_entity() correctly

[Abel Wu]

On 11/16/23 7:52 PM, Abel Wu Wrote:
> Please add a Fix tag like this:
>
> Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")

Can you resend this patch with this fix tag please?

> On 11/16/23 7:42 PM, Yiwei Lin Wrote:
> > Since reweight_entity() may have chance to change the weight of
> > cfs_rq->curr entity, we should also update_min_vruntime() if
> > this is the case
> >
> > Signed-off-by: Yiwei Lin <s921975628@xxxxxxxxx>
> > ---
> >   kernel/sched/fair.c | 20 ++++++++++----------
> >   1 file changed, 10 insertions(+), 10 deletions(-)
> >
> > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> > index 07f555857..6fb89f4a3 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -3815,17 +3815,17 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
> >       enqueue_load_avg(cfs_rq, se);
> >       if (se->on_rq) {
> >           update_load_add(&cfs_rq->load, se->load.weight);
> > -        if (!curr) {
> > -            /*
> > -             * The entity's vruntime has been adjusted, so let's check
> > -             * whether the rq-wide min_vruntime needs updated too. Since
> > -             * the calculations above require stable min_vruntime rather
> > -             * than up-to-date one, we do the update at the end of the
> > -             * reweight process.
> > -             */
> > +        if (!curr)
> >               __enqueue_entity(cfs_rq, se);
> > -            update_min_vruntime(cfs_rq);
> > -        }
> > +
> > +        /*
> > +         * The entity's vruntime has been adjusted, so let's check
> > +         * whether the rq-wide min_vruntime needs updated too. Since
> > +         * the calculations above require stable min_vruntime rather
> > +         * than up-to-date one, we do the update at the end of the
> > +         * reweight process.
> > +         */
> > +        update_min_vruntime(cfs_rq);
> >       }
> >   }
>
> LGTM, thanks!