Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272162AbTHDTYq (ORCPT ); Mon, 4 Aug 2003 15:24:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S272163AbTHDTYq (ORCPT ); Mon, 4 Aug 2003 15:24:46 -0400 Received: from almesberger.net ([63.105.73.239]:20485 "EHLO host.almesberger.net") by vger.kernel.org with ESMTP id S272162AbTHDTYo (ORCPT ); Mon, 4 Aug 2003 15:24:44 -0400 Date: Mon, 4 Aug 2003 16:24:33 -0300 From: Werner Almesberger To: "Eric W. Biederman" Cc: Jeff Garzik , Nivedita Singhvi , netdev@oss.sgi.com, linux-kernel@vger.kernel.org Subject: Re: TOE brain dump Message-ID: <20030804162433.L5798@almesberger.net> References: <20030802140444.E5798@almesberger.net> <3F2BF5C7.90400@us.ibm.com> <3F2C0C44.6020002@pobox.com> <20030802184901.G5798@almesberger.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from ebiederm@xmission.com on Sun, Aug 03, 2003 at 01:21:09PM -0600 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1375 Lines: 33 Eric W. Biederman wrote: > The optimized for low latency cases seem to have a strong > market in clusters. Clusters have captive, no, _desperate_ customers ;-) And it seems that people are just as happy putting MPI as their transport on top of all those link-layer technologies. > There is one place in low latency communications that I can think > of where TCP/IP is not the proper solution. For low latency > communication the checksum is at the wrong end of the packet. That's one of the few things ATM's AAL5 got right. But in the end, I think it doesn't really matter. At 1 Gbps, an MTU-sized packet flies by within 13 us. At 10 Gbps, it's only 1.3 us. At that point, you may well treat it as an atomic unit. > On that score it is worth noting that the next generation of > peripheral busses (Hypertransport, PCI Express, etc) are all switched. And it's about time for that :-) - Werner -- _________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina werner@almesberger.net / /_http://www.almesberger.net/____________________________________________/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/