From owner-svn-src-all@FreeBSD.ORG Sun Oct 28 22:12:52 2012 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id A540530B for ; Sun, 28 Oct 2012 22:12:52 +0000 (UTC) (envelope-from andre@freebsd.org) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.freebsd.org (Postfix) with ESMTP id 08B3F8FC0C for ; Sun, 28 Oct 2012 22:12:51 +0000 (UTC) Received: (qmail 93116 invoked from network); 28 Oct 2012 23:49:53 -0000 Received: from c00l3r.networx.ch (HELO [127.0.0.1]) ([62.48.2.2]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 28 Oct 2012 23:49:53 -0000 Message-ID: <508DADE1.6050900@freebsd.org> Date: Sun, 28 Oct 2012 23:12:49 +0100 From: Andre Oppermann User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20121010 Thunderbird/16.0.1 MIME-Version: 1.0 To: Rui Paulo Subject: Re: svn commit: r242261 - head/sys/netinet References: <201210281902.q9SJ272D078237@svn.freebsd.org> <6FC10C06-9288-4E2C-A1A2-33C5CC8086C5@felyko.com> <508DAA07.9090103@freebsd.org> <81A9846E-CC54-4822-A5B4-EF37D00B42B3@felyko.com> In-Reply-To: <81A9846E-CC54-4822-A5B4-EF37D00B42B3@felyko.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Oct 2012 22:12:52 -0000 On 28.10.2012 23:01, Rui Paulo wrote: > On Oct 28, 2012, at 14:56, Andre Oppermann wrote: > >> On 28.10.2012 22:34, Rui Paulo wrote: >>> On 28 Oct 2012, at 12:02, Andre Oppermann wrote: >>> >>>> Author: andre >>>> Date: Sun Oct 28 19:02:07 2012 >>>> New Revision: 242261 >>>> URL: http://svn.freebsd.org/changeset/base/242261 >>>> >>>> Log: >>>> For retransmits of SYN|ACK from the syncache use the slightly more >>>> aggressive special tcp_syn_backoff[] retransmit schedule instead of >>>> the normal tcp_backoff[] schedule for established connections. >>> >>> >>> How did you came up with the values for tcp_syn_backoff? I obviously >>> understand the aggressiveness, but did you measure any significant >>> improvement in connection establishment time and if so, on what type of links? >> >> I didn't come up with the values. tcp_syn_backoff[] was introduced >> almost 12 years ago by jlemon. For syncache it got lost somewhere >> along the line. > > Oh, I see. I read it backwards. > >> >> There has been recent talk by some large FreeBSD web server operators >> of reducing SYN|ACK retransmit timeouts. This change fixes a part of >> the problem. The recent RFC on reducing the RTO will fix the other >> part. > > Which RFC? I'm only aware of draft-hurtig-tcpm-rtorestart. RFC6298. -- Andre