From owner-freebsd-net@FreeBSD.ORG  Tue Jan  8 16:45:43 2013
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
 by hub.freebsd.org (Postfix) with ESMTP id 1C278813
 for <freebsd-net@freebsd.org>; Tue,  8 Jan 2013 16:45:43 +0000 (UTC)
 (envelope-from smithi@nimnet.asn.au)
Received: from sola.nimnet.asn.au (paqi.nimnet.asn.au [115.70.110.159])
 by mx1.freebsd.org (Postfix) with ESMTP id 643C0CC1
 for <freebsd-net@freebsd.org>; Tue,  8 Jan 2013 16:45:41 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
 by sola.nimnet.asn.au (8.14.2/8.14.2) with ESMTP id r08GY0ID074549;
 Wed, 9 Jan 2013 03:34:01 +1100 (EST)
 (envelope-from smithi@nimnet.asn.au)
Date: Wed, 9 Jan 2013 03:34:00 +1100 (EST)
From: Ian Smith <smithi@nimnet.asn.au>
To: Garrett Cooper <yanegomi@gmail.com>
Subject: Re: To SMP or not to SMP
In-Reply-To: <D889FFD5-6832-43B9-A6BA-93111C619F35@gmail.com>
Message-ID: <20130109032940.H30575@sola.nimnet.asn.au>
References: <1357660252.29936.YahooMailClassic@web121603.mail.ne1.yahoo.com>
 <D889FFD5-6832-43B9-A6BA-93111C619F35@gmail.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Cc: Barney Cordoba <barney_cordoba@yahoo.com>,
 Erich Dollansky <erichsfreebsdlist@alogt.com>, freebsd-net@freebsd.org
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 08 Jan 2013 16:45:43 -0000

On Tue, 8 Jan 2013 07:57:04 -0800, Garrett Cooper wrote:
 > On Jan 8, 2013, at 7:50 AM, Barney Cordoba wrote:
 > 
 > > --- On Mon, 1/7/13, Erich Dollansky <erichsfreebsdlist@alogt.com> wrote:
 > > 
 > >> From: Erich Dollansky <erichsfreebsdlist@alogt.com>
 > >> Subject: Re: To SMP or not to SMP
 > >> To: "Barney Cordoba" <barney_cordoba@yahoo.com>
 > >> Cc: freebsd-net@freebsd.org
 > >> Date: Monday, January 7, 2013, 10:56 PM
 > >> Hi,
 > >> 
 > >> On Mon, 7 Jan 2013 18:25:58 -0800 (PST)
 > >> Barney Cordoba <barney_cordoba@yahoo.com>
 > >> wrote:
 > >> 
 > >>> I have a situation where I have to run 9.1 on an old
 > >> single core box.
 > >>> Does anyone have a handle on whether it's better to
 > >> build a non SMP
 > >>> kernel or to just use a standard SMP build with just
 > >> the one core?
 > >>> Thanks.
 > >> 
 > >> I ran a single CPU version of FreeBSD until my last single
 > >> CPU got hit
 > >> by a lightning last April or May without any problems.
 > >> 
 > >> I never saw a reason to include the overhead of SMP for this
 > >> kind of
 > >> machine and I also never ran into problems with this.
 > > 
 > > Another "ass"umption based on logic rather than empirical evidence.
 > 
 > 	It isn't really an offhanded assumption because there _is_ 
 > additional overhead added into the kernel structures to make things 
 > work SMP with locking :). Whether or not it's measurable for you and 
 > your applications, I have no idea.
 > HTH,
 > -Garrett

Where's Kris Kennaway when you need something compared, benchmarked 
under N different types of loads, and nicely graphed?  Do we have a 
contender? :)

cheers, Ian