Re: [RFC][PATCH 1/5] sched/fair: Fix select_idle_cpu()s cost accounting

[Vincent Guittot]

On Fri, 8 Jan 2021 at 20:45, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Fri, Jan 08, 2021 at 04:10:51PM +0100, Vincent Guittot wrote:
> > Also, there is another problem (that I'm investigating)  which is that
> > this_rq()->avg_idle is stalled when your cpu is busy. Which means that
> > this avg_idle can just be a very old and meaningless value. I think
> > that we should decay it periodically to reflect there is less and less
>
> https://lkml.kernel.org/r/20180530143105.977759909@xxxxxxxxxxxxx
>
> :-)

:-)

I was more thinking of something like decaying avg_idle during
tick_fair but at leat we all agree that we can't stay with a stalled
avg_idle value