Re: [PATCH v5 05/10] cpufreq/schedutil: get max utilization

From: Joel Fernandes
Date: Tue May 29 2018 - 01:08:41 EST


On Mon, May 28, 2018 at 12:12:34PM +0200, Juri Lelli wrote:
[..]
> > +
> > + util = max_t(unsigned long, util, READ_ONCE(rq->avg_dl.util_avg));
> > +
> > + return util;
>
> Anyway, just a quick thought. I guess we should experiment with this a
> bit. Now, I don't unfortunately have a Arm platform at hand for testing.
> Claudio, Luca (now Cc-ed), would you be able to fire some tests with
> this change?
>
> Oh, adding Joel and Alessio as well that experimented with DEADLINE
> lately.

I also feel that for power reasons, dl.util_avg shouldn't drive the OPP
beyond what the running bandwidth is, or atleast do that only if CFS tasks
are running and being preempted as you/Vincent mentioned in one of the
threads.

With our DL experiments, I didn't measure power but got it to a point where
the OPP is scaling correctly based on DL parameters. I think Alessio did
measure power at his setup but I can't recall now. Alessio?

thanks,

- Joel