linux-kernel - Re: [PATCH 0/7] x86/topology: Improve CPUID.1F handling

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Message-ID: <57686aa5-b0bb-cd49-370c-ad1b376c48fd@roeck-us.net>
Date:   Fri, 12 Aug 2022 09:09:59 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Zhang Rui <rui.zhang@...el.com>,
        LKML <linux-kernel@...r.kernel.org>, x86@...r.kernel.org
Cc:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
        dave.hansen@...ux.intel.com, "H. Peter Anvin" <hpa@...or.com>,
        Len Brown <len.brown@...el.com>,
        "Yu, Fenghua" <fenghua.yu@...el.com>
Subject: Re: [PATCH 0/7] x86/topology: Improve CPUID.1F handling

On 8/12/22 08:08, Zhang Rui wrote:
> On Intel AlderLake-N platforms where there are Ecores only, the Ecore
> Module topology is enumerated via CPUID.1F Module level, which has not
> been supported by Linux kernel yet.
> 
> This exposes two issues in current CPUID.1F handling code.
> 1. Linux interprets the Module id bits as package id and erroneously
> reports a multi module system as a multi-package system.
> 2. Linux excludes the unknown Module id bits from the core_id, and
> results in duplicate core_id’s shown in a package after the first issue
> solved.
> 
> Plus that, a third problem is observed on Intel Hybrid ADL-S/P
> platforms. The return value of CPUID.1F SMT level EBX (number of
> siblings) differs on Pcore CPUs and Ecore CPUs, and results in
> inconsistent smp_num_siblings value based on the Pcore/Ecore CPU
> enumeration order.
> 
> Patch 1/7 and 2/7 fix the first two issues. And at the same time, it
> reveals a reality that the core_id could be sparse on platforms with
> CPUID.1F support.
> Patch 3/7 improves coretemp driver code to be able to handle sparse and
> large core id, which is the only driver that uses core_id as array
> index and run on platforms with CPUID.1F support.
> 

So far I only got this e-mail (and I don't find any of the other patches
elsewhere either), and it looks like the hwmon mailing list was not copied
on any of the patches. Please copy the hwmon mailing list for all changes
in hwmon code.

Thanks,
Guenter