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    SubjectRe: [PATCH v5 05/10] cpufreq/schedutil: get max utilization
    On 29/05/18 08:48, Vincent Guittot wrote:
    > On 29 May 2018 at 08:31, Juri Lelli <juri.lelli@redhat.com> wrote:
    > > On 28/05/18 22:08, Joel Fernandes wrote:
    > >> 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.
    > >
    > > It's however a bit awkward that we might be running at a higher OPP when
    > > CFS tasks are running (even though they are of less priority). :/
    >
    > Even if cfs task has lower priority that doesn't mean that we should
    > not take their needs into account.
    > In the same way, we run at max OPP as soon as a RT task is runnable

    Sure. What I fear is a little CFS utilization generating spikes because
    dl.util_avg became big when running DL tasks. Not sure that can happen
    though because such DL tasks should be throttled anyway.

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