From owner-sc22wg5@open-std.org Sat Dec 6 21:20:12 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id 585BCCA5FE7; Sat, 6 Dec 2008 21:20:12 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from ppsw-1.csi.cam.ac.uk (ppsw-1.csi.cam.ac.uk [131.111.8.131]) by www2.open-std.org (Postfix) with ESMTP id C86C9CA5FE4 for ; Sat, 6 Dec 2008 21:20:11 +0100 (CET) X-Cam-AntiVirus: no malware found X-Cam-SpamDetails: not scanned X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Received: from hermes-1.csi.cam.ac.uk ([131.111.8.51]:48190) by ppsw-1.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.151]:25) with esmtpa (EXTERNAL:nmm1) id 1L93dK-0003p6-5q (Exim 4.70) for sc22wg5@open-std.org (return-path ); Sat, 06 Dec 2008 20:20:10 +0000 Received: from prayer by hermes-1.csi.cam.ac.uk (hermes.cam.ac.uk) with local (PRAYER:nmm1) id 1L93dK-0000rW-Pn (Exim 4.67) for sc22wg5@open-std.org (return-path ); Sat, 06 Dec 2008 20:20:10 +0000 Received: from [83.67.89.123] by webmail.hermes.cam.ac.uk with HTTP (Prayer-1.3.1); 06 Dec 2008 20:20:10 +0000 Date: 06 Dec 2008 20:20:10 +0000 From: "N.M. Maclaren" To: WG5 Subject: Re: [ukfortran] (SC22WG5.3745) (j3.2006) Nick's MPI non-blocking proposal Message-ID: In-Reply-To: <20081204231430.B8E58CA5FE4@www2.open-std.org> References: <200812031523.23143.donev1@llnl.gov> <20081204045036.63332C56CF8@www2.open-std.org> <49384DD8.9000104@cray.com> <20081204231430.B8E58CA5FE4@www2.open-std.org> X-Mailer: Prayer v1.3.1 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=ISO-8859-1 Sender: owner-sc22wg5@open-std.org Precedence: bulk On Dec 4 2008, Aleksandar Donev wrote: >Bill Long wrote: > >> Actually, I find it massively confusing. \ > >No surprise, since you are confused about what Nick means by I/O. Nick's >proposal is meant to cover send/receive as well. It is I/O in common >computer science lingo, which I am aware is different from Fortran (file >I/O) and some other practices (likely Cray's internal terminology). Just >replace I/O with "data transfer" and you should be less confused reading >his draft. That is correct. I did try to explain, but clearly not thoroughly enough, by pointing out that MPI-1 transfers can be implemented (modulo the type matching) using Fortran I/O. Send and receive (as with TCP/IP and pipes), viewed functionally, are simply I/O between two processes, rather than between a process and a storage unit. Currently, a lot of parallel work is done by connecting Fortran units to pipes or sockets. Regards, Nick Maclaren, University of Cambridge Computing Service, New Museums Site, Pembroke Street, Cambridge CB2 3QH, England. Email: nmm1@cam.ac.uk Tel.: +44 1223 334761 Fax: +44 1223 334679