[MPI3 Fortran] One more MPI Fortran thing...

[Craig Rasmussen]

This is a good question that Bill Long should respond to.

Bill has long claimed that Cray's coarray implementation works fine with their MPI library.  I'm not sure what this means precisely.  Certainly there is no problem with using the MPI API with a coarray program that I can think of because MPI would just do send/recv using local memory (but I can imagine some interesting race conditions if users aren't careful).  I would guess that mpirun would have to know it is running a coarray program so that the two runtimes don't interfere with each other.

I think running a hybrid MPI and coarray program will be common as MPI has more functionality at the moment (and probably always as it is library based).

-craig

On Jan 21, 2010, at 6:42 PM, Purushotham Bangalore wrote:

> The other issue that I remember after the meeting: Since co-arrays will be part of the F08 standard, are they any potential issues that we need to be aware of? Or will the solutions from the Hybrid programming WG solve any potential problems that might arise?
> 
> Thanks
> Puri
> ----- Original Message -----
> From: "Jeff Squyres" <jsquyres at cisco.com>
> To: "Craig Rasmussen" <crasmussen at newmexicoconsortium.org>
> Cc: "Craig Rasmussen" <crasmussen at lanl.gov>, "Purushotham Bangalore" <puri at cis.uab.edu>
> Sent: Thursday, January 21, 2010 7:04:05 PM
> Subject: One more MPI Fortran thing...
> 
> Craig -- I forgot to mention this on the phone today: Puri asked in the Atlanta meeting today if we need to say anything about F08 in MPI-3.  I.e., do we need a paragraph/page/section/whatever about any issues that we expect might occur with using the explicit interface with F08 compilers?
> 
> -- 
> Jeff Squyres
> jsquyres at cisco.com
>