From owner-freebsd-hackers@FreeBSD.ORG Fri Apr 11 09:43:04 2003 Return-Path: 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 ECC1D37B404; Fri, 11 Apr 2003 09:43:03 -0700 (PDT) Received: from samson.dc.luth.se (samson.dc.luth.se [130.240.112.30]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0EDD643F75; Fri, 11 Apr 2003 09:43:02 -0700 (PDT) (envelope-from bj@dc.luth.se) Received: from dc.luth.se (root@bompe.dc.luth.se [130.240.60.42]) by samson.dc.luth.se (8.12.5/8.12.5) with ESMTP id h3BGgwjY023931; Fri, 11 Apr 2003 18:42:58 +0200 (MET DST) Received: from bompe.dc.luth.se (bj@localhost.dc.luth.se [127.0.0.1]) by dc.luth.se (8.12.6/8.11.3) with ESMTP id h3BGgwKl087226; Fri, 11 Apr 2003 18:42:58 +0200 (CEST) (envelope-from bj@bompe.dc.luth.se) Message-Id: <200304111642.h3BGgwKl087226@dc.luth.se> X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Terry Lambert In-reply-to: Your message of Fri, 11 Apr 2003 09:32:51 PDT. <3E96EE33.FAF4FABB@mindspring.com> Dcc: X-Disposition-notification-to: Borje.Josefsson@dc.luth.se X-uri: http://www.dc.luth.se/~bj/index.html Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Date: Fri, 11 Apr 2003 18:42:57 +0200 From: Borje Josefsson cc: freebsd-hackers@freebsd.org cc: freebsd-performance@freebsd.org cc: "Jin Guojun \[DSD\]" cc: Eric Anderson cc: David Gilbert 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 Reply-To: bj@dc.luth.se List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Apr 2003 16:43:04 -0000 On Fri, 11 Apr 2003 09:32:51 PDT Terry Lambert wrote: > Borje Josefsson wrote: > > > A good thing to look at at this point would be: > > > > > > o Clean boot of FreeBSD target > > > o Run NetBSD against it > > > o Save statistics > > = > > What type of statistics do You mean? > = > Dropped packets; frags; delayed acks. The stuff you get from > "netstat -s" and "netstat -m". > = > > > You mean "bandwidth delay product". Yes, assuming you have packet > > > loss. From your description of your setup, packet loss should not > > > be possible, so we can discount it as a factor. > > = > > Of cause packet loss is possible on a nationwide network. If I loose = a > > packet on the (expected) 10 second test (with NetBSD), recovering fro= m > > that drops performance from 900+ to ~550 Mbps. Thos shows very clearl= y if > > I run "netstat 1". > = > You are running these tests over .se's nationwide network? One of them, I'm using GigaSunet, the nationwide network for the = universities in Sweden. 10 Gbps to 22 cities, connecting 35 universities = with 2,5G (redundant). This not a "research network" per se, it's the = "production" network for the universities. If I suceeed with this, the = next challenge (no kidding) is to try the same thing over the commodity = Internet from here to California (or sonething similar), showing that You= = don't need a "private" network for high speed communication if You do = things right. After that I've thought of testing against Japan or New = Zealand, which is about as far You can get from here :-) --B=F6rje