Subject: Re: How to detect multi-core and/or HT-enabled CPUs in 2.4.x and
	2.6.x kernels
From: Arjan van de Ven <arjan@infradead.org>
To: knobi@knobisoft.de
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <666716.84435.qm@web32603.mail.mud.yahoo.com>
References: <666716.84435.qm@web32603.mail.mud.yahoo.com>
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Organization: Intel International BV
Date: Wed, 27 Dec 2006 15:24:30 +0100
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On Wed, 2006-12-27 at 06:16 -0800, Martin Knoblauch wrote:
> Hi, (please CC on replies, thanks)
> 
>  for the ganglia project (http://ganglia.sourceforge.net/) we are
> trying to find a heuristics to determine the number of physical CPU
> "cores" as opposed to virtual processors added by enabling HT. The
> method should work on 2.4 and 2.6 kernels.

I have a counter question for you.. what are you trying to do with the
"these two are SMT sibblings" information ?

Because I suspect "HT" is the wrong level of detection for what you
really want to achieve....

If you want to decide "shares caches" then at least 2.6 kernels directly
export that (and HT is just the wrong way to go about this). 
-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

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