Re: Commit 554c8aa8ecad causing severe performance degression with pcc-cpufreq

From: Rafael J. Wysocki
Date: Tue Jul 17 2018 - 05:06:33 EST


On Tue, Jul 17, 2018 at 10:50 AM, Andreas Herrmann <aherrmann@xxxxxxxx> wrote:

[cut]

>
> On balance before this commit users could use pcc-cpufreq but had
> already suboptimal performance (compared to say intel_pstate driver
> which can be used changing BIOS options).

BTW, I wonder why you need to change the BIOS options for intel_pstate to load.

It should be initialized before pcc-cpufreq (according to their
respective initcall levels), so in theory intel_pstate should be used
by default on the affected systems anyway.

What BIOS settings need to be changed for that?