(j3.2006) (SC22WG5.3879) [ukfortran] [MPI3 Fortran] MPI non-blocking transfers

N.M. Maclaren nmm1
Wed Jan 21 18:41:59 EST 2009

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.

Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QH, England.
Email:  nmm1 at cam.ac.uk
Tel.:  +44 1223 334761    Fax:  +44 1223 334679

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