Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 8 Oct 2002 19:51:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 8 Oct 2002 19:51:29 -0400 Received: from svr-ganmtc-appserv-mgmt.ncf.coxexpress.com ([24.136.46.5]:47632 "EHLO svr-ganmtc-appserv-mgmt.ncf.coxexpress.com") by vger.kernel.org with ESMTP id ; Tue, 8 Oct 2002 19:51:28 -0400 Subject: Re: bug 2 cpus shows as 4 cpus From: Robert Love To: Jeff Chua Cc: Linux Kernel In-Reply-To: References: Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 (1.0.8-10) Date: 08 Oct 2002 19:57:08 -0400 Message-Id: <1034121428.29468.1876.camel@phantasy> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 919 Lines: 25 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/