Hi, Thanks. AFAIK, the requirement is that the changes in MPI-2.2 should not break existing applications. I've always seen this as a semantic and an ABI constraint. If compile time changes are allowed, this may strongly delay adoption of the MPI-2.2 by the shrink-wrapped ISV applications. In any case, MPI-2.2 will have to offer substantially more new capabilities than the current set of tickets in order to make this change pay off. Don't forget about the ISV need for supporting many MPIs either. Some of them - both MPIs and applications - may prefer to stay in the 2.1 era to prevent forcing their customers to recompile. Best regards. Alexander -----Original Message----- From: mpi-22-bounces_at_[hidden] [mailto:mpi-22-bounces_at_[hidden]] On Behalf Of William Gropp Sent: Friday, April 03, 2009 8:48 PM To: MPI 2.2 Subject: Re: [Mpi-22] [MPI Forum] #59: Clarification on MPI::FILE_NULL, MPI::WIN_NULL and MPI::COMM_NULL I've viewed this as a source-code requirement - Applications require no changes in their source code. That permits requiring recompilation. Bill On Apr 3, 2009, at 1:06 PM, Jeff Squyres wrote:

This is worth raising to the list.

What is the rule for 2.2 -- that existing MPI applications must be able to run with no changes against an MPI-2.2 library? Or is it that existing MPI applications must be able to compile and run with no source code changes against an MPI-2.2 implementation?

I hope it's the latter; this change is relatively important.

On Apr 3, 2009, at 5:56 AM, MPI Forum wrote:

...

#59: Clarification on MPI::FILE_NULL, MPI::WIN_NULL and MPI::COMM_NULL ----------------------------------- +---------------------------------------- Reporter: hubertritzdorf | Owner: hubertritzdorf Type: Correction to standard | Status: new Priority: Waiting for reviews | Milestone: 2009/04/06 Chicago Version: MPI 2.2 | Resolution: Keywords: | Implementation: Completed ----------------------------------- +---------------------------------------- Changes (by asupalov):

* cc: alexander.supalov_at_[hidden] (added)

Comment:

Aren't we changing C++ ABI herewith? If so, we may want to postpone this change till MPI-3.

-- Ticket URL: <https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/ 59#comment:33

...

MPI Forum <https://svn.mpi-forum.org/> MPI Forum

-- Jeff Squyres Cisco Systems

_______________________________________________ mpi-22 mailing list mpi-22_at_[hidden] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-22

William Gropp Deputy Director for Research Institute for Advanced Computing Applications and Technologies Paul and Cynthia Saylor Professor of Computer Science University of Illinois Urbana-Champaign _______________________________________________ mpi-22 mailing list mpi-22_at_[hidden] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-22 --------------------------------------------------------------------- Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen Germany Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer Registergericht: Muenchen HRB 47456 Ust.-IdNr. VAT Registration No.: DE129385895 Citibank Frankfurt (BLZ 502 109 00) 600119052 This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.