Re: [RFC][PATCH v2 2/2] cpufreq: schedutil: Avoid decreasing frequency of busy CPUs

From: Peter Zijlstra
Date: Tue Mar 21 2017 - 11:04:32 EST


On Tue, Mar 21, 2017 at 03:46:07PM +0100, Rafael J. Wysocki wrote:
> @@ -207,6 +212,8 @@ static void sugov_update_single(struct u
> if (!sugov_should_update_freq(sg_policy, time))
> return;
>
> + sg_policy->overload = this_rq()->rd->overload;
> +

Same problem as before; rd->overload is set if _any_ CPU in the root
domain has more than 1 runnable task at a random point in history (when
we ran the load balance tick -- and since that is the same tick used for
timers, there's a bias to over-account there).