From owner-freebsd-net@FreeBSD.ORG Mon Feb 26 07:25:37 2007 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 BD57B16A400 for ; Mon, 26 Feb 2007 07:25:37 +0000 (UTC) (envelope-from jfvogel@gmail.com) Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.243]) by mx1.freebsd.org (Postfix) with ESMTP id 78E4913C461 for ; Mon, 26 Feb 2007 07:25:37 +0000 (UTC) (envelope-from jfvogel@gmail.com) Received: by an-out-0708.google.com with SMTP id c24so746808ana for ; Sun, 25 Feb 2007 23:25:36 -0800 (PST) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=UfxYshnYfJmLEvAUtvBtwrsleAfeoFw1hABLkQFII01+SIshcIRBe0jsXs2zdOCz+9KjIExdIPQtBOoAg9E95uTKcBa5k60zIYamySmTsN+r/giwkwuP88QSnTS14Z2acvBpqQVmSYk8a8222HzviD/MXxEJ49aiGTRD0wcwO0s= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=q6rwC+Bru+edxs23dUPcyccz16a2ubP1ogT7RUT6d/wCh2udmr7N3d6UJm+WVMNRl7G0kM9nsCYEYzGNqp/oNW45Alb1iVGzlMgICUVk0Fgc/PTG01KPkUa0Jz+5dPHkwOM7Ckfpc+JIF6A4kZC+tjnxeG3x4wVPFC9LOMx1O2c= Received: by 10.114.112.1 with SMTP id k1mr549005wac.1172474736365; Sun, 25 Feb 2007 23:25:36 -0800 (PST) Received: by 10.114.103.15 with HTTP; Sun, 25 Feb 2007 23:25:30 -0800 (PST) Message-ID: <2a41acea0702252325k4ec64d59m95a63bebaf6ea30c@mail.gmail.com> Date: Sun, 25 Feb 2007 23:25:30 -0800 From: "Jack Vogel" To: "Kip Macy" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <45E19B54.9060007@freebsd.org> <45E1A3B4.7090002@freebsd.org> <2a41acea0702252053v2357b5f5tefbcf58375be1a2f@mail.gmail.com> Cc: freebsd-net , Andre Oppermann Subject: Re: improved TSO interface needed 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: Mon, 26 Feb 2007 07:25:37 -0000 On 2/25/07, Kip Macy wrote: > > The stack will send down chains where pkthdr.len > 65536 bytes - I'm > also seeing it send down mbuf chains of 66 mbufs or more. I don't > think all cards can handle an arbitrary number of descriptors being > used for a single packet. 64K is the max, and I believe that is taking into account the headers. What size are you seeing that is larger? Even if an mbuf chain comes down that large, it does NOT form a single packet, it is packetized by the hardware into MTU size, as I said, on the wire, ie as the receiver sees it, its just a lot of packets. The only question is whether the transmit hardware can handle it. Do you have eivdence of some hardware that supports TSO in the driver that cant?? Jack