From owner-freebsd-net@FreeBSD.ORG Tue Feb 5 21:40:23 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 120D726A; Tue, 5 Feb 2013 21:40:23 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net [IPv6:2001:470:1f10:75::2]) by mx1.freebsd.org (Postfix) with ESMTP id DEA829A2; Tue, 5 Feb 2013 21:40:22 +0000 (UTC) Received: from pakbsde14.localnet (unknown [38.105.238.108]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 54C42B91E; Tue, 5 Feb 2013 16:40:22 -0500 (EST) From: John Baldwin To: Andre Oppermann Subject: Re: [PATCH] Add a new TCP_IGNOREIDLE socket option Date: Tue, 5 Feb 2013 16:40:21 -0500 User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110714-p22; KDE/4.5.5; amd64; ; ) References: <201301221511.02496.jhb@freebsd.org> <201302051211.43345.jhb@freebsd.org> <511144FB.50807@freebsd.org> In-Reply-To: <511144FB.50807@freebsd.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201302051640.21412.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Tue, 05 Feb 2013 16:40:22 -0500 (EST) Cc: Sepherosa Ziehau , freebsd-net@freebsd.org, Bjoern Zeeb X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Feb 2013 21:40:23 -0000 On Tuesday, February 05, 2013 12:44:27 pm Andre Oppermann wrote: > On 05.02.2013 18:11, John Baldwin wrote: > > On Wednesday, January 30, 2013 12:26:17 pm Andre Oppermann wrote: > >> You can simply create your own congestion control algorithm with only the > >> restart window changed. See (pseudo) code below. BTW, I just noticed that > >> the other cc algos don't do not reset the idle window. > > > > *sigh* I am fully competent at maintaining my own local changes. The point > > was to share this so that other people with similar workloads could make use > > of it. Also, a custom CC algo is not the right approach as we would want this > > change regardless of the CC algo used for handling non-idle periods (so that > > this is an orthogonal knob). Linux also makes this an orthogonal knob rather > > than requiring a separate CC algo. > > If everything Linux does is good, then go ahead and commit it. Discussing > this change further then is pointless. I don't mind too much and I have > stated my case why I think it's the wrong thing to do. Not everything Linux does is good, nor is everything Linux does bad. > I would prefer to encapsulate it into its own not-so-much-congestion-management > algorithm so you can eventually do other tweaks as well like more aggressive > loss recovery which would fit your objective as well. Since you have to modify > your app anyways to do the sockopt call this seems a more complete solution to > me. At least better than to do a non-portable hack that violates one of the > most fundamental TCP concepts. This is real rich from the guy pushing the increased IW that came from Linux. :) "Tools not policy" yadda yadda, but I digress. -- John Baldwin