Re: [tip:sched/core] sched/fair: Fix rounding bug for asym packing

From: Vincent Guittot
Date: Mon Jan 21 2019 - 08:22:32 EST


On Mon, 21 Jan 2019 at 13:47, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
>
> Sorry guys, I seem to have messed this up :/
>
> Valentin pointed me out that I missed v3 and v4 of these patches; v3 got

I was about to sent an email about that too

> lost in the x-mas pile and v4 was actually on my todo list for this
> week, but I'd forgotten I'd already queued v2.
>
> I'll go queue delta patches.

Thanks

>
> On Mon, Jan 21, 2019 at 03:33:53AM -0800, tip-bot for Vincent Guittot wrote:
> > index 50aa2aba69bd..2ccd6e093326 100644
> > --- a/kernel/sched/fair.c
> > +++ b/kernel/sched/fair.c
> > @@ -8190,6 +8190,12 @@ static inline void update_sg_lb_stats(struct lb_env *env,
> > /* Adjust by relative CPU capacity of the group */
> > sgs->group_capacity = group->sgc->capacity;
> > sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) / sgs->group_capacity;
> > + /*
> > + * Prevent division rounding to make the computation of imbalance
> > + * slightly less than original value and to prevent the rq to be then
> > + * selected as busiest queue:
> > + */
> > + sgs->avg_load += 1;
> >
> > if (sgs->sum_nr_running)
> > sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
>
>