[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Patching Octave-MPI
From: |
Andy Jacobson |
Subject: |
Re: Patching Octave-MPI |
Date: |
21 Nov 2002 11:51:19 -0500 |
User-agent: |
Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 |
>>>>> "Paul" == Paul Kienzle <address@hidden> writes:
Paul> There are a variety of approaches to parallelism which have
Paul> been done in matlab m-files and mex-files. E.g.,
Alex Verstak raised an interesting point last year: he said that the
MPI standard requires that MPI_Init() be fed the *original* argv and
argc. (Yes, it is arguably a silly requirement.) With at least MPICH
apparently, MPI_Init() would not work from a .oct file. See:
http://www.octave.org/mailing-lists/help-octave/2001/141
Later however, Alex apparently did get it running:
http://www.octave.org/mailing-lists/help-octave/2001/218
So perhaps a .oct solution will work.
Note however that the parallelized Matlab solutions all are guided by
two facts: (1) they cannot modify the source code so the
parallelization has to work via .mex/.m files, and (2) due to the cost
of multiple Matlab licenses, there may be implicit assumptions about
how many instances are running in a given MPI application. There may
be hidden performance issues.
It should a pretty trivial matter to determine whether or not the user
wants a parallel or traditional application when she starts octave.
Perhaps something as simple as "octave --mpi-server" or "octave
--mpi-client". Then we call MPI_Init() (and later MPI_Finalize()) as
appropriate. That is just about all that is required from the main
code; the rest could naturally be moved to .oct.
Regards,
Andy
--
Andy Jacobson
address@hidden
Program in Atmospheric and Oceanic Sciences
Sayre Hall, Forrestal Campus
Princeton University
PO Box CN710 Princeton, NJ 08544-0710 USA
Tel: 609/258-5260 Fax: 609/258-2850