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Date: Fri, 1 Jul 2016 20:29:21 +0200
From: Borislav Petkov <bp@suse.de>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@elte.hu>,
        "H. Peter Anvin" <h.peter.anvin@intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Stephane Eranian <eranian@google.com>,
        Ravi V Shankar <ravi.v.shankar@intel.com>,
        Vikas Shivappa <vikas.shivappa@linux.intel.com>,
        linux-kernel <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>
Subject: Re: [PATCH] cacheinfo: Introduce cache id
Message-ID: <20160701182921.GD4749@pd.tnic>
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On Fri, Jul 01, 2016 at 11:00:35AM -0700, Luck, Tony wrote:
> For CAT we only need the IDs to be unique at each level. Our tentative
> syntax for the schema file for CAT looks like this (for a theoretical
> system supporting CAT in both L2 and L3 with two L3 caches and eight L2 caches)
> 
> L3:id0=fff;id1=ff0
> L2:id0=3;id1=c;id2=30;id3=c0;id4=3;id5=c;id6=30;id7=c0

So wouldn't it be straightforward and natural to do the following
nomenclature (which basically suggests itself):

ID<level>.<num>

?

So that the ID hierarchy above is:

ID3.0 ID3.1
ID2.0 ID2.1 ID2.2 ID2.3 ... ID2.7

I don't know if that's useful though.

I mean, we have that info in the path anyway:

/sys/devices/system/cpu/cpu0/cache/index3/id = 0xfff
...

and so on.

Whatever you do, as long as the nomenclature is documented somewhere,
say Documentation/x86/topology.txt, for example, we should be fine.

-- 
Regards/Gruss,
    Boris.

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