linux-kernel - RE: [PATCH] x86/AMD: Fix Socket ID for LLC topology for AMD Fam17h systems

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Message-ID: <alpine.DEB.2.20.1609021508550.5647@nanos>
Date:   Fri, 2 Sep 2016 15:13:31 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     "Ghannam, Yazen" <Yazen.Ghannam@....com>
cc:     "mingo@...hat.com" <mingo@...hat.com>,
        "hpa@...or.com" <hpa@...or.com>, "x86@...nel.org" <x86@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Borislav Petkov <bp@...en8.de>
Subject: RE: [PATCH] x86/AMD: Fix Socket ID for LLC topology for AMD Fam17h
 systems

On Fri, 2 Sep 2016, Ghannam, Yazen wrote:
> > > The Socket ID is ApicId[bits] on Fam17h systems.
> > >
> > > Change substraction to logical AND when extracting socket_id
> > > from c->apicid.
> > 
> > So Fam17h will only ever have 2 sockets, right?
> > 
> 
> This is the decoding of the ApicId shown in our latest Programming
> Reference.

I have no idea what your latest reference manual says as it seems to be not
yet public.

> However, I can remove the "& 1" if you think it'll be better.

I's not about what I think is better.

I asked the obvious question whether Fam17h will only ever have two sockets,
because your patch limits it hard to that.

Care to answer that very question instead of handwaving about your
interpretation of a secret manual?

Thanks,

	tglx