From owner-svn-src-all@FreeBSD.ORG Sun Oct 28 22:01:24 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 993E2155; Sun, 28 Oct 2012 22:01:24 +0000 (UTC) (envelope-from rpaulo@felyko.com) Received: from felyko.com (unknown [IPv6:2607:f2f8:a528::3:1337:ca7]) by mx1.freebsd.org (Postfix) with ESMTP id 7499B8FC08; Sun, 28 Oct 2012 22:01:24 +0000 (UTC) Received: from [10.0.1.38] (c-50-131-226-51.hsd1.ca.comcast.net [50.131.226.51]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by felyko.com (Postfix) with ESMTPSA id 0464A39828; Sun, 28 Oct 2012 15:01:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=felyko.com; s=mail; t=1351461684; bh=7vCnyOuGLeQRQDhmaszAEhVxQ1rta5tOvjD8/pKwjPg=; h=References:In-Reply-To:Cc:From:Subject:Date:To; b=Q2CZRm9ntX/Fw7qYZf6Bk9EDG0m6R4JiZDGwZ28uhIvYE7gzKxObDQozfCXasxJv3 WYUlTGuskeQlrzypD+cVr079XG0WMvOWwgpvLCc15nv6cBJXtnfvylK4qX2di8n3zw 0hawa5es0Um8aPkZIBwpJOFMyyPDLwwwsxM9WAmU= References: <201210281902.q9SJ272D078237@svn.freebsd.org> <6FC10C06-9288-4E2C-A1A2-33C5CC8086C5@felyko.com> <508DAA07.9090103@freebsd.org> Mime-Version: 1.0 (1.0) In-Reply-To: <508DAA07.9090103@freebsd.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Message-Id: <81A9846E-CC54-4822-A5B4-EF37D00B42B3@felyko.com> X-Mailer: iPhone Mail (10A505) From: Rui Paulo Subject: Re: svn commit: r242261 - head/sys/netinet Date: Sun, 28 Oct 2012 15:01:24 -0700 To: Andre Oppermann 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 22:01:24 -0000 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: >>=20 >>> Author: andre >>> Date: Sun Oct 28 19:02:07 2012 >>> New Revision: 242261 >>> URL: http://svn.freebsd.org/changeset/base/242261 >>>=20 >>> 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. >>=20 >>=20 >> 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 l= inks? >=20 > 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.=20 >=20 > 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.=20=