Re: [PATCH v2] cpufreq: schedutil: rate limits for SCHED_DEADLINE

[Claudio Scordino <claudio@evidence.eu.com>]

Dear Rafael, dear Viresh,

Il 28/02/2018 12:06, Claudio Scordino ha scritto:
> 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).

As a follow up of the previous thread, I've put some figures here: https://gist.github.com/claudioscordino/d4a10e8b3ceac419fb0c8b552db19806

In some cases, I've noticed the patch to even reduce the energy consumption (due to a mix of factors plus DL tasks entering the inactive state sooner).

I've also tried to create the "ramp-up" scenario by allocating 10 DL tasks on the same core, but it didn't produce any significant increase of consumption.

IMHO, the overall behavior looks better.

Best regards,

              Claudio