Re: [RFC PATCH 2/4] cpufreq: acpi-cpufreq: Add processor to the ignore PSD override list

From: Borislav Petkov
Date: Mon Dec 14 2020 - 07:41:57 EST


On Sat, Dec 12, 2020 at 08:36:48AM +0900, Punit Agrawal wrote:
> To me it suggests, that there are likely more systems from the family
> that show the characteristic described below.

Until we find a *single* system with a broken BIOS which has those
objects kaputt and then this heuristic would need an exception.

VS the clear statement from AMD that from zen3 onwards, all BIOS will be
tested. I hope they boot Linux at least before they ship.

> In all these systems, the override causes this topology information to
> be ignored - treating each core to be a separate domain. The proposed
> patch removes the override so that _PSD is taken into account.

You're still not answering my question: what does the coupling of the
SMT threads bring on those systems? Power savings? Perf improvement?
Anything palpable or measurable?

Thx.

--
Regards/Gruss,
Boris.

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