From owner-freebsd-hackers@FreeBSD.ORG  Fri Mar 17 16:40:11 2006
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
X-Original-To: freebsd-hackers@freebsd.org
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B2E2E16A400
	for <freebsd-hackers@freebsd.org>; Fri, 17 Mar 2006 16:40:10 +0000 (UTC)
	(envelope-from jhb@freebsd.org)
Received: from server.baldwin.cx (66-23-211-162.clients.speedfactory.net
	[66.23.211.162])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 2493443D45
	for <freebsd-hackers@freebsd.org>; Fri, 17 Mar 2006 16:40:10 +0000 (GMT)
	(envelope-from jhb@freebsd.org)
Received: from localhost (john@localhost [127.0.0.1])
	by server.baldwin.cx (8.13.4/8.13.4) with ESMTP id k2HGe3Iu054949;
	Fri, 17 Mar 2006 11:40:03 -0500 (EST) (envelope-from jhb@freebsd.org)
From: John Baldwin <jhb@freebsd.org>
To: freebsd-hackers@freebsd.org
Date: Fri, 17 Mar 2006 11:39:05 -0500
User-Agent: KMail/1.9.1
References: <20060317085746.S15860@quartz.bos.dyndns.com>
In-Reply-To: <20060317085746.S15860@quartz.bos.dyndns.com>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200603171139.07121.jhb@freebsd.org>
X-Virus-Scanned: ClamAV 0.87.1/1335/Wed Mar 15 23:58:43 2006 on
	server.baldwin.cx
X-Virus-Status: Clean
X-Spam-Status: No, score=-3.6 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 
	autolearn=ham version=3.1.0
X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on server.baldwin.cx
Cc: Tom Daly <tom@dyndns.com>
Subject: Re: Recommended SMP Config
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 17 Mar 2006 16:40:11 -0000

On Friday 17 March 2006 09:04, Tom Daly wrote:
> Hi,
> I'm running FreeBSD 6.0 Release (amd64) on Dell Poweredge 2850s. So far, 
> so good. I'm doing a pretty vanilla install of things, enabling SMP in the 
> kernel, and that's pretty much it. This server has 2 EM64T CPUs in it.
> 
> When looking at top, CPU 1 rarely shows up with processes on it. systat 
> does show it idle most of the time. Why is this? Why do processes land on 
> CPU 0, 2, and 3 in most cases.
> 
> Also, by setting machdep.hyperthreading_allowed=1, CPU 1 starts taking 
> process onto it.

Because CPU 1 is a hyperthread.  So is CPU 3 for that matter.

-- 
John Baldwin <jhb@FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org