Messages in this thread | | | From | Vincent Guittot <> | Date | Mon, 14 May 2018 11:20:53 +0200 | Subject | Re: [PATCH v2 2/3] sched/fair: util_est: update before schedutil |
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Hi Patrick,
On 11 May 2018 at 15:15, Patrick Bellasi <patrick.bellasi@arm.com> wrote: > When a task is enqueue the estimated utilization of a CPU is updated > to better support the selection of the required frequency. > However, schedutil is (implicitly) updated by update_load_avg() which > always happens before util_est_{en,de}queue(), thus potentially > introducing a latency between estimated utilization updates and > frequency selections. > > Let's update util_est at the beginning of enqueue_task_fair(), > which will ensure that all schedutil updates will see the most > updated estimated utilization value for a CPU. > > Reported-by: Vincent Guittot <vincent.guittot@linaro.org> > Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com> > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Vincent Guittot <vincent.guittot@linaro.org> > Cc: linux-kernel@vger.kernel.org > Cc: linux-pm@vger.kernel.org > Fixes: 7f65ea42eb00 ("sched/fair: Add util_est on top of PELT")
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
> > --- > > Changes in v2: > - improve comment in enqueue_task_fair() (Peter) > - add "Fixes" tag > - add "Acked-by" Viresh tag > ---
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