Re: [RFC PATCH v4 08/12] sched: Add over-utilization/tipping point indicator

[Quentin Perret]

On Friday 06 Jul 2018 at 15:24:28 (+0200), Peter Zijlstra wrote:
> On Fri, Jul 06, 2018 at 02:20:57PM +0100, Quentin Perret wrote:
> > So, what we try to do here is to _not_ set the overutilized flag based
> > on the utilization of a new task, because its utilization is 'wrong'.
> > That should help avoiding spurious transitions above the overutilized
> > threshold.
> 
> That most certainly deserves a comment,

Ok, will do.

> also didn't util_est fix some of that wrong-ness?

When a new task is enqueued, we don't have util_est samples yet, so the
task's util_est is equal to its util_avg. So util_est won't help here,
unfortunately.

But it does help in the wake-up path to predict what OPP will be
selected (see cpu_util_next() in patch 09/12).

Thanks,
Quentin