From owner-sc22wg5@open-std.org Thu Jan 22 00:42:00 2009 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 30FCFCA3439; Thu, 22 Jan 2009 00:42:00 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from ppsw-7.csi.cam.ac.uk (ppsw-7.csi.cam.ac.uk [131.111.8.137]) by www2.open-std.org (Postfix) with ESMTP id A58EFCA3434 for ; Thu, 22 Jan 2009 00:41:59 +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-2.csi.cam.ac.uk ([131.111.8.54]:41628) by ppsw-7.csi.cam.ac.uk (smtp.hermes.cam.ac.uk [131.111.8.157]:25) with esmtpa (EXTERNAL:nmm1) id 1LPmhr-0007RZ-OC (Exim 4.70) for sc22wg5@open-std.org (return-path ); Wed, 21 Jan 2009 23:41:59 +0000 Received: from prayer by hermes-2.csi.cam.ac.uk (hermes.cam.ac.uk) with local (PRAYER:nmm1) id 1LPmhr-00069H-Fk (Exim 4.67) for sc22wg5@open-std.org (return-path ); Wed, 21 Jan 2009 23:41:59 +0000 Received: from [83.67.89.123] by webmail.hermes.cam.ac.uk with HTTP (Prayer-1.3.1); 21 Jan 2009 23:41:59 +0000 Date: 21 Jan 2009 23:41:59 +0000 From: "N.M. Maclaren" To: WG5 Subject: Re: [ukfortran] (SC22WG5.3876) (j3.2006) [MPI3 Fortran] MPI non-blocking transfers Message-ID: In-Reply-To: <20090121224014.6CB63C178D9@www2.open-std.org> References: <49776DF7.1040900@cray.com> <20090121211748.130A5C178D9@www2.open-std.org> <20090121224014.6CB63C178D9@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 Jan 21 2009, Aleksandar Donev wrote: > >> As someone with experience of installing and supporting multiple >> different MPI's on multiple different systems, it is thoroughly >> undesirable. > >Anyone on the Fortran committee should find it "undesirable" that we >have a problem we know about, that can be solved, appears in many >codes, and is usually attributed to the language (instead of the MPI >Forum). We ought to fix this. It is simply our duty as the guardians of >the language. Yes. Equally seriously, the existing 'solutions' require all MPI programs that use the non-blocking calls to rely on undefined behaviour, that may (but is not required to be) supported by the processor by the use of compiler options (or otherwise). That's not acceptable in a reasonable language standard. 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