Date: Tue, 22 Mar 2005 11:55:22 +0000
From: "Dr. David Alan Gilbert" <gilbertd@treblig.org>
To: Dave Jones <davej@redhat.com>, Dan Maas <dmaas@maasdigital.com>,
       linux-kernel@vger.kernel.org
Subject: Re: Distinguish real vs. virtual CPUs?
Message-ID: <20050322115522.GN1450@gallifrey>
References: <20050321202726.A7630@morpheus> <20050322015603.GB19541@redhat.com>
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* Dave Jones (davej@redhat.com) wrote:
> Compare the 'physical id' fields of /proc/cpuinfo, and count
> how many unique values you get.
> Ie, on my dual+ht, I see..
> 
> physical id     : 0
> physical id     : 0
> physical id     : 3
> physical id     : 3
> 
> Which indicates 2 real CPUs split in two.

Is this guarenteed to be safe on all architectures?  Parsing
/proc/cpuinfo accross different architectures can be a bit hairy;
I'm thinking when non-x86 start to have multiple hardware threads
people might want to do the same thing.

Dave
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    | Running GNU/Linux on Alpha,68K| Happy  \ 
\ gro.gilbert @ treblig.org | MIPS,x86,ARM,SPARC,PPC & HPPA | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/
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