Re: [PATCH v2] x86/amd: Derive L3 shared_cpu_map from cpu_llc_shared_mask

From: Borislav Petkov
Date: Sat Jul 29 2017 - 23:49:27 EST


On Thu, Jul 27, 2017 at 08:52:35PM -0500, Suravee Suthikulpanit wrote:
> For system with X86_FEATURE_TOPOEXT, current logic use APIC ID to
> calculate shared_cpu_map. However, since APIC IDs are not guaranteed
> to be contiguous for cores across different L3 (e.g. family17h system
> w/ downcore configuration). This breaks the logic, and results in
> incorrect L3 shared_cpu_map.
>
> Instead, always use the previously calculated cpu_llc_shared_mask of
> each cpu to derive L3 shared_cpu_map. This has been tested on
> family15h and family17h systems, which has L3 and support
> X86_FEATURE_TOPOEXT.
>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> ---
> arch/x86/kernel/cpu/intel_cacheinfo.c | 32 ++++++++++++++++++--------------
> 1 file changed, 18 insertions(+), 14 deletions(-)

Applied, thanks.

--
Regards/Gruss,
Boris.

SUSE Linux GmbH, GF: Felix ImendÃrffer, Jane Smithard, Graham Norton, HRB 21284 (AG NÃrnberg)
--