This looks like you are using an mpirun or mpiexec from mvapich to run an executable compiled with OMPI.  Can you make sure that you are using the right mpirun?

--td

Pankatz, Klaus wrote:
Yes, I did that.

It ist basically the same problem with a Fortran version of this little program. With that I used the mpif90 command of openMPI.
________________________________________
Von: users-bounces@open-mpi.org [users-bounces@open-mpi.org] im Auftrag von Reuti [reuti@staff.uni-marburg.de]
Gesendet: Freitag, 23. April 2010 14:15
An: Open MPI Users
Betreff: Re: [OMPI users] mpirun -np 4 hello_world;     on a eight processor shared memory machine produces wrong output

Hi,

Am 23.04.2010 um 14:06 schrieb Pankatz, Klaus:

  
Hi all,

there's a problem with openMPI on my machine. When I simply try to run this little hello_world-program on multiple processors, the output isn't as expected:
*****
C code:
#include <mpi.h>
#include <stdio.h>
#include <unistd.h>
int main(int argc, char **argv)
{
 int size,rank;
 char hostname[50];
 MPI_Init(&argc,&argv);
 MPI_Comm_rank(MPI_COMM_WORLD, &rank); //Who am I?
 MPI_Comm_size(MPI_COMM_WORLD, &size); //How many processes?
 gethostname (hostname, 50);
 printf ("Hello World! I'm number %2d of %2d running on host %s\n",
rank, size, hostname);
 MPI_Finalize();
 return 0;
}
****

Command: mpirun -np 4 a.out
    

the mpirun (better, use: mpiexec) is the one from the Open MPI, and you also used its version mpicc to compile the program?

-- Reuti


  
Output:
Hello World! I'm number  0 of  1 running on host marvin
Hello World! I'm number  0 of  1 running on host marvin
Hello World! I'm number  0 of  1 running on host marvin
Hello World! I'm number  0 of  1 running on host marvin

It should be more or less:
Hello World! I'm number  1 of  4 running on host marvin
Hello World! I'm number  2 of  4 running on host marvin
....

OpenMPI-version 1.4.1 compiled with Lahey Fortran 95 (lf95).
OpenMPI was compiled "out of the box" only changing to the Lahey compiler with a setenv $FC lf95

The System: Linux marvin 2.6.27.6-1 #1 SMP Sat Nov 15 20:19:04 CET 2008 x86_64 GNU/Linux

Compiler: Lahey/Fujitsu Linux64 Fortran Compiler Release L8.10a

Thanks very much!
Klaus

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