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

From: Peter Zijlstra <peterz@infradead.org>
To: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, linux-kernel@vger.kernel.org, leo.duran@amd.com,
	yazen.ghannam@amd.com
Subject: Re: [PATCH 1/2] x86/CPU/AMD: Present package as die instead of socket
Date: Wed, 5 Jul 2017 17:50:53 +0200	[thread overview]
Message-ID: <20170705155053.jucdvggtxxczzkba@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <bb167d94-828b-2d5b-642a-d56e8db392d0@amd.com>

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.