Re: bug 2 cpus shows as 4 cpus

From: Robert Love (rml@tech9.net)
Date: Tue Oct 08 2002 - 18:57:08 EST


On Tue, 2002-10-08 at 19:39, Jeff Chua wrote:

> I'm running 2.4.20-pre9 on DELL server with Xeon dual processors, but
> /proc/cpuinfo shows not 2, but "4" cpus!
>
> The bogomips semms to indicate 2 cpus. (3971.48 is about 2GHz x 2).
>
> Is this problem related to Xeon? I've other SMP boxes with P3, but they
> reports correctly 2 cpus.

Hahaha, dude, you have hyper-threading! Each of your Xeons has two
logical processors that share most processor resources but implement two
independent pipelines. So you have four schedulable processors in
total.

Google around for hyper-threading, HT, and SMT. It is in all P4-class
Xeons and soon all regular P4s.

        Robert Love

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