From owner-freebsd-net@FreeBSD.ORG Thu Dec 14 01:13:33 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id BE80F16A50A for ; Thu, 14 Dec 2006 01:13:33 +0000 (UTC) (envelope-from chrcoluk@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.191]) by mx1.FreeBSD.org (Postfix) with ESMTP id AAB4443CA1 for ; Thu, 14 Dec 2006 01:11:52 +0000 (GMT) (envelope-from chrcoluk@gmail.com) Received: by nf-out-0910.google.com with SMTP id x37so646821nfc for ; Wed, 13 Dec 2006 17:13:15 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=omtauxkiBokEbv9/uM3Jrb+YHNvfVoQ5HNJYvS78W/6AKNicJYTVaockXbcxKKlMH/l7Pl6bYKdPD8XoHQT18EoHsa+S3f8nVbAQv7XFJCC9JWfCh00bjSTsK3UGjEMHnOvyZmHuymbYYV2PcAilrdoWxpXYZkzFelZMtm9l35o= Received: by 10.82.110.14 with SMTP id i14mr151311buc.1166058381277; Wed, 13 Dec 2006 17:06:21 -0800 (PST) Received: by 10.82.134.15 with HTTP; Wed, 13 Dec 2006 17:06:21 -0800 (PST) Message-ID: <3aaaa3a0612131706w5ae75edcvadd7958274a1e2e2@mail.gmail.com> Date: Thu, 14 Dec 2006 01:06:21 +0000 From: Chris To: "Andre Oppermann" In-Reply-To: <457F2D82.6000905@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <457F2D82.6000905@freebsd.org> Cc: freebsd-net@freebsd.org, freebsd-current@freebsd.org Subject: Re: Automatic TCP send and receive socket buffer sizing X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Dec 2006 01:13:33 -0000 On 12/12/06, Andre Oppermann wrote: > This is a patch adding automatic TCP send and receive socket buffer sizing. > Normally the socket buffers are static (either derived from global defaults > or set with setsockopt) and do not adapt to real network conditions. Two > things happen: a) your socket buffers are too small and you can't reach the > full potential of the network between both hosts; b) your socket buffers are > too big and you waste a lot of kernel memory for data just sitting around. > > With automatic TCP send and receive socket buffers we can start with a small > buffer and quickly grow it in parallel with the TCP congestion window to match > real network conditions. > > FreeBSD has a default 32K send socket buffer. This supports a maximal > transfer rate of only slightly more than 2Mbit/s on a 100ms RTT trans- > continental link. Or at 200ms just above 1Mbit/s. With TCP send buffer > auto scaling and the default values below it supports 20Mbit/s at 100ms > and 10Mbit/s at 200ms. That's an improvement of factor 10, or 1000%. > For the receive side it looks slightly better with a default of 64K buffer > size. > > The automatic send buffer sizing patch is currently running on one half of > the FTP.FreeBSD.ORG cluster w/o any problems so far. Against this machine > with the automatic receive buffer sizing patch I can download at 5.7MBytes > per second. Without patch it maxed out at 1.6MBytes per second as the delay > bandwidth product became equal to the static socket buffer size without hitting > the limits of the physical link between the machines. My test machine is about > 35ms from that FTP.FreeBSD.ORG and connected through a moderately loaded 100Mbit > Internet link. > > New sysctl's are: > > net.inet.tcp.sendbuf_auto=1 (enabled) > net.inet.tcp.sendbuf_inc=8192 (8K, step size) > net.inet.tcp.sendbuf_max=262144 (256K, growth limit) > net.inet.tcp.recvbuf_auto=1 (enabled) > net.inet.tcp.recvbuf_inc=16384 (16K, step size) > net.inet.tcp.recvbuf_max=262144 (256K, growth limit) > > The patch is available here (it may apply with some fuzz): > > http://people.freebsd.org/~andre/tcp_auto_buf-20061212.diff > > Any tests and test reports are very welcome. > > -- > Andre Hi does this patch work on 6.x? I used the send patch on 6.x and works great please make a 6.x patch thank you and I will happily test. Chris