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

From: Peter Zijlstra
Date: Tue Mar 21 2017 - 11:02:37 EST


On Tue, Mar 21, 2017 at 03:26:06PM +0100, Rafael J. Wysocki wrote:
> + if ((flags & SCHED_CPUFREQ_RT_DL) || this_rq()->rd->overload) {
> next_f = policy->cpuinfo.max_freq;

So this I think is wrong; rd->overload is set if _any_ of the CPUs in the
root domain is overloaded. And given the root domain is typically the
_entire_ machine, this would have a tendency to run at max_freq far too
often.