Re: [PATCH v5 00/10] track CPU utilization

Juri Lelli
2018-06-05T15:03:07Z

On 05/06/18 16:18, Peter Zijlstra wrote:
> On Mon, Jun 04, 2018 at 08:08:58PM +0200, Vincent Guittot wrote:

[...]

> > As you mentioned, scale_rt_capacity give the remaining capacity for
> > cfs and it will behave like cfs util_avg now that it uses PELT. So as
> > long as cfs util_avg < scale_rt_capacity(we probably need a margin)
> > we keep using dl bandwidth + cfs util_avg + rt util_avg for selecting
> > OPP because we have remaining spare capacity but if cfs util_avg ==
> > scale_rt_capacity, we make sure to use max OPP.
>
> Good point, when cfs-util < cfs-cap then there is idle time and the util
> number is 'right', when cfs-util == cfs-cap we're overcommitted and
> should go max.
>
> Since the util and cap values are aligned that should track nicely.

Yeah. Makes sense to me as well. :)