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Re: Patching Octave-MPI
From: |
Paul Kienzle |
Subject: |
Re: Patching Octave-MPI |
Date: |
Thu, 21 Nov 2002 12:04:34 -0500 |
User-agent: |
Mutt/1.2.5.1i |
So maybe we need the equivalent of gcc's -Wl,"blah", so that octave
m-files/octave-files can receive parameters from the command line
that octave ignores? From there we can build a pretend original
argc/argv pair to hand to MPI.
Paul Kienzle
address@hidden
On Thu, Nov 21, 2002 at 11:51:19AM -0500, Andy Jacobson wrote:
> >>>>> "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
>