[MPI3 Fortran] Nonblocking MPI and Fortran temporary memory modifications

[Rolf Rabenseifner]

Craig, is there a protocol, file, ... on 
http://www.nag.co.uk/sc22wg5/
where this vote is protocolled?
Rolf

----- Original Message -----
> From: "Craig E Rasmussen" <rasmussn at lanl.gov>
> To: "Rolf Rabenseifner" <rabenseifner at hlrs.de>
> Cc: "MPI-3 Fortran working group" <mpi3-fortran at lists.mpi-forum.org>, "N.M. Maclaren" <nmm1 at cam.ac.uk>, "Bill Long"
> <longb at cray.com>, "Reinhold Bader" <reinhold.bader at lrz.de>
> Sent: Monday, March 28, 2011 6:14:00 PM
> Subject: Re: Nonblocking MPI and Fortran temporary memory modifications
> We've had several discussions regarding the use of ASYNCHRONOUS for
> the usage required by MPI on the J3 committee. Some members thought
> that ASYNCHRONOUS shouldn't be used apart from I/O. However, a vote
> was taken and a large majority voted that the ASYNCHRONOUS attribute
> should be used for this purpose.
> 
> So the question is not about whether a compiler implements
> ASYNCHRONOUS I/O but whether it respects the ASYNCHRONOUS semantics.
> Perhaps we need an interp request to formalize this beyond a simple J3
> member vote.
> 
> -craig
> 
> 
> On Mar 27, 2011, at 3:34 AM, Rolf Rabenseifner wrote:
> 
> > Dear all,
> >
> > Reinhold showed me that the ASYNCHRONOUS attribute may not help
> > because a compiler may implement asynchronous Fortran I/O
> > with blocking I/O and therefore may ignore all ASYNCHRONOUS
> > attributes.
> >
> > Please have a look at
> > https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/ticket/229/mpi-report-F2008-2011-03-26-changeonly-majorpages.pdf
> >
> > Pages 24-31 in the pdf (pages 549-556 in the original document)
> > show our knowledge about the nonblocking and datatype (MPI_BOTTOM)
> > problems
> > in the combination of Fortran and MPI.
> >
> > Unfortunately in the taböle on page 550, we have to modify all
> > entries
> > about ASYNCHRONOUS into "NOT solved".
> >
> > Do you see further solutions?
> >
> > Do you see further problems with nonblocking and "MPI_BOTTOM",
> > that are not mentioned in this section and that should be.
> >
> > Is the rest of this section correct?
> > If something is incorrect, it would be important to understand why.
> >
> > I've reworked this section based on many discussions and on my best
> > knowledge - but I'm not sure whether this was enough.
> >
> > Best regards
> > Rolf
> >
> >
> > --
> > Dr. Rolf Rabenseifner . . . . . . . . . .. email
> > rabenseifner at hlrs.de
> > High Performance Computing Center (HLRS) . phone
> > ++49(0)711/685-65530
> > University of Stuttgart . . . . . . . . .. fax ++49(0)711 /
> > 685-65832
> > Head of Dpmt Parallel Computing . . .
> > www.hlrs.de/people/rabenseifner
> > Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30)

-- 
Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner at hlrs.de
High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530
University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832
Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner
Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30)