Re: octave-mpi questions

[Martin Siegert]

On Tue, Feb 18, 2003 at 01:36:18PM -0500, Andy Jacobson wrote:

> I think JD's on the right track with the oct file idea, but I can't
> confirm that his implementation works.  I don't have access to a
> working MPI platform at this time.  
> 
> No matter how this works out, I think it's rather important that the
> load/save functions for reading and writing octave values to and from
> streams (and thus to other MPI-aware octave instances) be included.
> This could be considered an octave-specific analog of the MPI_Send()
> and MPI_Recv() functions.

I am not sure whether you can get around the requirements of the
MPI standard, namely that you must not call any MPI functions
before having called MPI_Init and you must not call any MPI functions
after having called MPI_Finalized, in particular, the standard says
that MPI_Init cannot be called after a call to MPI_Finalize - one cannot
restart MPI once the MPI environment has been cleaned up. Thus,
the observation that Octave exits when MPI_Init is called a second
time seems to be what is supposed to happen (and not only a speciality
of LAM).
Thus, I do not believe that there is a way to let users restart MPI
and therefore I think a solution that ensures that MPI_Init and
MPI_Finalize are called just once is the only way to go.

If you want me to test solutions, I am happy to do this. I have
current versions of MPICH and LAM installed on my cluster.

Cheers,
Martin

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Martin Siegert
Academic Computing Services                        phone: (604) 291-4691
Simon Fraser University                            fax:   (604) 291-4242
Burnaby, British Columbia                          email: address@hidden
Canada  V5A 1S6
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