From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270432AbTGMW4R (ORCPT ); Sun, 13 Jul 2003 18:56:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270433AbTGMW4R (ORCPT ); Sun, 13 Jul 2003 18:56:17 -0400 Received: from pizda.ninka.net ([216.101.162.242]:18118 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id S270432AbTGMW4P (ORCPT ); Sun, 13 Jul 2003 18:56:15 -0400 Date: Sun, 13 Jul 2003 16:02:00 -0700 From: "David S. Miller" To: Roland Dreier Cc: alan@storlinksemi.com, linux-kernel@vger.kernel.org, linux-net@vger.kernel.org, netdev@oss.sgi.com Subject: Re: TCP IP Offloading Interface Message-Id: <20030713160200.571716cf.davem@redhat.com> In-Reply-To: <52u19qwg53.fsf@topspin.com> References: <20030713004818.4f1895be.davem@redhat.com> <52u19qwg53.fsf@topspin.com> X-Mailer: Sylpheed version 0.9.2 (GTK+ 1.2.6; sparc-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 13 Jul 2003 09:22:32 -0700 Roland Dreier wrote: > David> TOE is evil, read this: > > David> http://www.usenix.org/events/hotos03/tech/full_papers/mogul/mogul.pdf > Your ideas are certainly very interesting, and I would be happy to see > hardware that supports flow identification. But the Usenix paper > you're citing completely disagrees with you! I didn't say I agree with all of Moguls ideas, just his anti-TOE arguments. For example, I also think RDMA sucks too yet he thinks it's a good iea. > For example, Mogul writes: > > "Nevertheless, copy-avoidance designs have not been widely adopted, > due to significant limitations. For example, when network maximum > segment size (MSS) values are smaller than VM page sizes, which is > often the case, page-remapping techniques are insufficient (and > page-remapping often imposes overheads of its own.)" On send this doesn't matter, on receive you use my clever receive buffer handling + flow cache idea to accumulate the data portion of packets into page sized chunks for the networking to flip. You obviously don't understand my ideas if you think that it matters whether there is some relationship between the MTU and the system page size necessary for the scheme to work.