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Brice Goglin edited this page Mar 2, 2018 · 26 revisions

AMD 24-core EPYC

  • L3 (cpuset 0x60000060) intersects with NUMANode (P#0 cpuset 0x3f00003f nodeset 0x00000001) without inclusion!

Fixed in 4.14 in commit

commit 2b83809a5e6d619a780876fcaf68cdc42b50d28c
Author: Suravee Suthikulpanit <[email protected]>
Date:   Mon Jul 31 10:51:59 2017 +0200

    x86/cpu/amd: Derive L3 shared_cpu_map from cpu_llc_shared_mask
    
    For systems with X86_FEATURE_TOPOEXT, current logic uses the APIC ID
    to calculate shared_cpu_map. However, APIC IDs are not guaranteed to
    be contiguous for cores across different L3s (e.g. family17h system
    w/ downcore configuration). This breaks the logic, and results in an
    incorrect L3 shared_cpu_map.
    
    Instead, always use the previously calculated cpu_llc_shared_mask of
    each CPU to derive the L3 shared_cpu_map.

Backported in upstream 4.13.16.

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