From owner-freebsd-current@FreeBSD.ORG Mon Sep 4 08:00:16 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BE2CC16A4DD for ; Mon, 4 Sep 2006 08:00:16 +0000 (UTC) (envelope-from pyunyh@gmail.com) Received: from py-out-1112.google.com (py-out-1112.google.com [64.233.166.180]) by mx1.FreeBSD.org (Postfix) with ESMTP id 07F2343D58 for ; Mon, 4 Sep 2006 08:00:14 +0000 (GMT) (envelope-from pyunyh@gmail.com) Received: by py-out-1112.google.com with SMTP id o67so2788953pye for ; Mon, 04 Sep 2006 01:00:14 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:date:from:to:cc:subject:message-id:reply-to:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=SQ/pCZ8SdijetmLna9xPYIDNRWYUuK1VjetfGvLeKVXz8h/AkFtmKKRMaB2o8OASmKkQMG5nuNbUtk0qhNndKuVu5BIPV/q9a9GYcShgvf2oZzsj0AdIVMEiqVMGYqpwIkmQq3QoxhhrTn8YEJtRayu8niihHQo0ruGQPLUYmac= Received: by 10.35.128.1 with SMTP id f1mr9588909pyn; Mon, 04 Sep 2006 01:00:14 -0700 (PDT) Received: from michelle.cdnetworks.co.kr ( [211.53.35.84]) by mx.gmail.com with ESMTP id 38sm2361681nza.2006.09.04.01.00.13; Mon, 04 Sep 2006 01:00:14 -0700 (PDT) Received: from michelle.cdnetworks.co.kr (localhost.cdnetworks.co.kr [127.0.0.1]) by michelle.cdnetworks.co.kr (8.13.5/8.13.5) with ESMTP id k847wOHD002106 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 4 Sep 2006 16:58:24 +0900 (KST) (envelope-from pyunyh@gmail.com) Received: (from yongari@localhost) by michelle.cdnetworks.co.kr (8.13.5/8.13.5/Submit) id k847wNDx002105; Mon, 4 Sep 2006 16:58:23 +0900 (KST) (envelope-from pyunyh@gmail.com) Date: Mon, 4 Sep 2006 16:58:23 +0900 From: Pyun YongHyeon To: Jack Vogel Message-ID: <20060904075823.GA1210@cdnetworks.co.kr> References: <2a41acea0609011551v40338539u4eef48d091dd12ab@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2a41acea0609011551v40338539u4eef48d091dd12ab@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Cc: freebsd-net , freebsd-current Subject: Re: RFC: TSO patch for current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: pyunyh@gmail.com List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Sep 2006 08:00:16 -0000 On Fri, Sep 01, 2006 at 03:51:21PM -0700, Jack Vogel wrote: > This is a patch for the stack and the em driver to enable TSO > on CURRENT. Previously I had problems getting it to work, but > this is functional. > > I should note that CURRENT is being a pain right now, when > I comment out em in the config the kernel panics coming up, > so I had to substitute this code into the tree. Rather bizarre :) > > I have this functionality running on a 6.1 based system, and > our test group is already testing against that driver, so far > things are looking good. > > I have designed it so the driver can continue to be built > without support. There is also a sysctl in the stack code > so you can set net.inet.tcp.tso_enable on or off and > compare. > > I know there may be some refinements to add in, but I > would like to get this into CURRENT as a start. > > Comments? > It seems that 8254x also supports UDP segmentation offloading feature. Have you tried to implement it? According to the data sheet checksums are not accurate above 12K frame size but I couldn't find frame size restrictions in TSO path. What is maximum frame size supported by TSO? It seems that TSO assumes IP/TCP/UDP checksum offloading is always enabled by hardware. What if users disable IP/TCP/UDP checksum offloading with ifconfig(8)? What happen if users disable hardware VLAN tag insertion with ifconfig(8)? It woud be even better if users can disable/enable TSO capability for each network devices with ifconfig(8) instead of relying on global sysctl MIB(net.inet.tcp.tso_enable). Btw, do you have benchmark numbers? > Jack -- Regards, Pyun YongHyeon