Re: [PATCH] cpufreq: schedutil: Don't skip freq update when limits change

Rafael J. Wysocki
2019-07-23T09:13:30Z

On Tue, Jul 23, 2019 at 9:10 AM Doug Smythies <dsmythies@telus.net> wrote:
>
> On 2019.07.21 23:52 Viresh Kumar wrote:
>
> > To avoid reducing the frequency of a CPU prematurely, we skip reducing
> > the frequency if the CPU had been busy recently.
> >
> > This should not be done when the limits of the policy are changed, for
> > example due to thermal throttling. We should always get the frequency
> > within limits as soon as possible.
> >
> > Fixes: ecd288429126 ("cpufreq: schedutil: Don't set next_freq to UINT_MAX")
> > Cc: v4.18+ <stable@vger.kernel.org> # v4.18+
> > Reported-by: Doug Smythies <doug.smythies@gmail.com>
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > ---
> > @Doug: Please try this patch, it must fix the issue you reported.
>
> It fixes the driver = acpi-cpufreq ; governor = schedutil test case
> It does not fix the driver = intel_cpufreq ; governor = schedutil test case

So what's the difference between them, with the patch applied?

> I have checked my results twice, but will check again in the day or two.

OK, thanks!