Re: [PATCH v4] cpufreq: schedutil: rate limits for SCHED_DEADLINE

From: Joel Fernandes
Date: Tue Mar 13 2018 - 21:28:04 EST


On Tue, Mar 13, 2018 at 4:15 AM, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> On 13-03-18, 11:35, Claudio Scordino wrote:
>> When the SCHED_DEADLINE scheduling class increases the CPU utilization,
>> we should not wait for the rate limit, otherwise we may miss some
>> deadline.
>>
>> Tests using rt-app on Exynos5422 with up to 10 SCHED_DEADLINE tasks have
>> shown reductions of even 10% of deadline misses with a negligible
>> increase of energy consumption (measured through Baylibre Cape).
>>
>> Signed-off-by: Claudio Scordino <claudio@xxxxxxxxxxxxxxx>
>> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
>> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>> CC: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>> CC: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
>> CC: Patrick Bellasi <patrick.bellasi@xxxxxxx>
>> CC: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
>> CC: Morten Rasmussen <morten.rasmussen@xxxxxxx>
>> CC: Juri Lelli <juri.lelli@xxxxxxxxxx>
>> CC: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
>> CC: Todd Kjos <tkjos@xxxxxxxxxxx>
>> CC: Joel Fernandes <joelaf@xxxxxxxxxx>
>> CC: linux-pm@xxxxxxxxxxxxxxx
>> CC: linux-kernel@xxxxxxxxxxxxxxx
>> ---
>> Changes from v3:
>> - Specific routine renamed as ignore_dl_rate_limit()
>
> LGTM. Thanks.

Nice! Thanks.

- Joel