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From: Zhang Rui <>
Subject: [PATCH V2 0/8] x86/topology: Improve CPUID.1F handling
Date: Tue, 16 Aug 2022 13:16:25 +0800	[thread overview]
Message-ID: <> (raw)

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. This could bring
some potential issues although we have not observed any functionalities
issues so far.

This patch series fixes these three problems in CPUID.1F handling code,
together with some related fixes and document updates.


Changes since V1:
 - fix/improve changelog/comment wording issues
 - reorder the patches to eliminate bisection breakage window
 - add a new patch for coretemp driver variable renaming
 - update coretemp driver patch to fix a case of ida_free(&ida, -2)

             reply	other threads:[~2022-08-16  7:57 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-16  5:16 Zhang Rui [this message]
2022-08-16  5:16 ` [PATCH V2 1/8] perf/x86/intel/P4: Fix smp_num_siblings usage Zhang Rui
2022-08-16  8:27   ` Peter Zijlstra
2022-08-16  9:47     ` Zhang Rui
2022-08-16 10:08       ` Peter Zijlstra
2022-08-16  5:16 ` [PATCH V2 2/8] hwmon/coretemp: Rename indx to index Zhang Rui
2022-08-16  5:16 ` [PATCH V2 3/8] hwmon/coretemp: Handle large core ID value Zhang Rui
2022-08-16 11:16   ` Guenter Roeck
2022-08-16  5:16 ` [PATCH V2 4/8] x86/topology: Fix multiple packages shown on a single-package system Zhang Rui
2022-09-21 16:26   ` Dave Hansen
2022-09-22 13:38     ` Zhang Rui
2022-08-16  5:16 ` [PATCH V2 5/8] x86/topology: Fix duplicated core ID within a package Zhang Rui
2022-08-16  5:16 ` [PATCH V2 6/8] x86/topology: Fix max_siblings calculation Zhang Rui
2022-08-16  5:16 ` [PATCH V2 7/8] Documentation: x86: Update smp_num_siblings/x86_max_cores description Zhang Rui
2022-08-16  5:16 ` [PATCH V2 8/8] Documentation: x86: Remove obsolete x86_max_dies description Zhang Rui
2022-09-20  1:57 ` [PATCH V2 0/8] x86/topology: Improve CPUID.1F handling Zhang Rui

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