Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Run a process double
From: Mark Potts (potts_at_[hidden])
Date: 2007-11-28 22:27:41

    Apologies ahead of time for any unintended insults, but...

    Your "a.out" sounds like it is not truly a parallel code. If you
    submit a hello_world program using OpenMPI's mpirun, you will simply
    get two copies of "Hello World" printed to the screen.

    If you want the work shared, you must change your serial program
    such that it executes different code pieces or operates on different
    portions of your data, based on something like the "rank" of the
    process. (Rank is the numerical ID assigned by MPI to each process
    running from a single invocation of mpirun.)

    All MPI, or specifically OpenMPI, provides you is a vehicle to
    launch multiple copies of a program or programs and then to
    facilitate the communication of those separate processes with
    one another.

    Perhaps a primer on parallel processing would be in order. Or since
    you have started with Message Passing, perhaps the old standard
    "Using MPI Portable Parallel Programming with the Message-Passing
    Interface, MIT Press, by Gropp, Lusk, and Skjellum would give you
    the familiarization needed. Other books in that series by some of
    the same authors are also good starting points for MPI. I'm sure
    other readers can pipe in with a host of better references.

    Good luck.

Henry Adolfo Lambis Miranda wrote:
> Hi everybody out there.....
> This is my first post to the mail list.
> I have installed openmp 1.2.4 over a x_64 AMD double processor with SuSE
> linux.
> In principal, the instalation was succefull, with ifort 10.X.
> But when i run any code ( mpirun -np 2 a.out), instead of share the
> calcules between the two
> processor, the system duplicate the executable and send one to each
> processor.
> i don´t know what the h$%& is going on......
> regards..
> Henry

 >> Mark J. Potts, PhD
 >> HPC Applications Inc.
 >> phone: 410-992-8360 Bus
 >>        410-313-9318 Home
 >>        443-418-4375 Cell
 >> email: potts_at_[hidden]
 >>        potts_at_[hidden]