Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S272801AbTHFFNR (ORCPT ); Wed, 6 Aug 2003 01:13:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S274870AbTHFFNR (ORCPT ); Wed, 6 Aug 2003 01:13:17 -0400 Received: from almesberger.net ([63.105.73.239]:50443 "EHLO host.almesberger.net") by vger.kernel.org with ESMTP id S272801AbTHFFNQ (ORCPT ); Wed, 6 Aug 2003 01:13:16 -0400 Date: Wed, 6 Aug 2003 02:13:04 -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: <20030806021304.E5798@almesberger.net> References: <20030802140444.E5798@almesberger.net> <3F2BF5C7.90400@us.ibm.com> <3F2C0C44.6020002@pobox.com> <20030802184901.G5798@almesberger.net> <20030804162433.L5798@almesberger.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from ebiederm@xmission.com on Tue, Aug 05, 2003 at 11:19:09AM -0600 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1881 Lines: 48 Eric W. Biederman wrote: > MPI is not a transport. It an interface like the Berkeley sockets > layer. Hmm, but doesn't it also unify transport semantics (i.e. chop TCP streams into messages), maybe add reliability to transports that don't have it, and provide addressing ? Okay, perhaps you wouldn't call this a transport in the OSI sense, but it still seems to have considerably more functionality than just providing an API. > Mostly I think the that is less true, at least if they can stand the > process of severe code review and cleaning up their code. Hmm, people putting dozens of millions into building clusters can't afford to have what is probably their most essential infrastructure code reviewed and cleaned up ? Oh dear. > But of course to get through the peer review process people need > to understand what they are doing. A good point :-) > So store and forward of packets in a 3 layer switch hierarchy, at 1.3 us > per copy. But your switch could just do cut-through, no ? Or do they need to recompute checksums ? > A lot of the NICs which are used for MPI tend to be smart for two > reasons. 1) So they can do source routing. 2) So they can safely > export some of their interface to user space, so in the fast path > they can bypass the kernel. The second part could be interesting for TOE, too. Only that the interface exported would just be the socket interface. - 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/