Re: [PATCH 1/2] x86/CPU/AMD: Present package as die instead of socket

From: Peter Zijlstra
Date: Wed Jul 05 2017 - 11:51:06 EST


On Tue, Jun 27, 2017 at 08:07:10PM +0700, Suravee Suthikulpanit wrote:

> As I have described in the cover letter, this patch series changes how

Which you didn't send to me... thanks for that.

> kernel derives cpu "package" from package-as-socket to package-as-die in
> order to fix following issues on AMD family17h multi-die processor
> platforms:

> These issues are fixed when properly intepretes package as DIE.
>
> For MCM Magny-Cours (family15h), we do not have this issue because the MC
> sched-domain has the same cpumask as the DIE sched-domain. This is not the
> same as for Zen cores (family17h) where the MC sched-domain is the CCX (2
> CCX per die)

Are you saying that your LLCs are smaller than your NUMA nodes ? You do
not in fact have a cache level that spans the memory controller?

Because that is indeed the assumption we have for Intel CoD/SnC and AMD
Magny-Cours.