[MPI3 Fortran] Nonblocking MPI and Fortran temporary memory modifications

[Rasmussen, Craig E]

I'll look for the vote in the minutes.

-craig

On Mar 28, 2011, at 4:12 PM, Rolf Rabenseifner wrote:

> 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)