From owner-freebsd-hackers@FreeBSD.ORG  Wed Apr  9 21:15:28 2003
Return-Path: <owner-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 8D74537B401; Wed,  9 Apr 2003 21:15:28 -0700 (PDT)
Received: from sabre.velocet.net (sabre.velocet.net [216.138.209.205])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id CB17643FCB; Wed,  9 Apr 2003 21:15:27 -0700 (PDT)
	(envelope-from dgilbert@velocet.ca)
Received: from trooper.velocet.ca (trooper.velocet.net [216.138.242.2])
	by sabre.velocet.net (Postfix) with ESMTP
	id 7EFE9138443; Thu, 10 Apr 2003 00:15:26 -0400 (EDT)
Received: by trooper.velocet.ca (Postfix, from userid 66)
	id 2065974D72; Thu, 10 Apr 2003 00:15:26 -0400 (EDT)
Received: by canoe.velocet.net (Postfix, from userid 101)
	id A0C3E56791B; Thu, 10 Apr 2003 00:14:35 -0400 (EDT)
From: David Gilbert <dgilbert@velocet.ca>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-ID: <16020.61355.551242.159558@canoe.velocet.net>
Date: Thu, 10 Apr 2003 00:14:35 -0400
To: "Jin Guojun [DSD]" <j_guojun@lbl.gov>
In-Reply-To: <3E94A8C4.3A196E42@lbl.gov>
References: <3E94A22D.174321F0@lbl.gov>
	<3E94A8C4.3A196E42@lbl.gov>
X-Mailer: VM 7.07 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid
cc: freebsd-hackers@freebsd.org
cc: freebsd-performance@freebsd.org
Subject: Re: tcp_output starving -- is due to mbuf get delay?
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
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: Thu, 10 Apr 2003 04:15:28 -0000

>>>>> "Jin" == Jin Guojun <[DSD]" <j_guojun@lbl.gov>> writes:

Jin> Some details was left behind -- The machine is 2 GHz Intel P4
Jin> with 1 GB memory, so the delay is not from either CPU or lack of
Jin> memory.

I just want to quickly jump in with the comment that our GigE tests of
routing through FreeBSD have exposed several-order-of-magnitude
differences by changing ram/motherboard/which-slot-the-card-is-in.

Do not assume that a fast CPU is the key.  We went through 10
motherboards to commission the current routers ... and sometimes
faster cpus would route slower (in various combinations of
motherboards and RAM).

Dave.

-- 
============================================================================
|David Gilbert, Velocet Communications.       | Two things can only be     |
|Mail:       dgilbert@velocet.net             |  equal if and only if they |
|http://daveg.ca                              |   are precisely opposite.  |
=========================================================GLO================