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Subject: Re: [PATCH] hyper-threading information in /proc/cpuinfo
From: Robert Love <rml@tech9.net>
To: "David D. Hagood" <wowbagger@sktc.net>
Cc: Jeff Garzik <jgarzik@pobox.com>, "Nakajima, Jun" <jun.nakajima@intel.com>,
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On Fri, 2002-10-25 at 19:45, David D. Hagood wrote:

> I would assert that, at least in the case of the P4, there IS a "major 
> core", as the 2 subcores share L1 and bus controller access, as well as 
> several other parts of the chip.
> 
> I beleive this is to some extent the case in the Power4 modules - that 
> each module contains resources shared by the execution units. However, I 
> might be full of it, and since there are plenty of @ibm.com's here I 
> expect to be corrected shortly....

You are entirely right :)

But argument for siblings vs. subcore is that in the context of the
processors displayed in /proc/cpuinfo known of them are "subscores" of
the other (and thus none of them are the "main core").

Some are just "siblings" in the same parent process package.  So given a
dual Xeon machine, you have 4 virtual processors, which are broken into
two sets of two siblings.  Those two sets are each part of the same
package.

	Robert Love

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