====== Job MPI ======

===== Intel MPI =====

Programma di test:
<code C>
#include "mpi.h"
#include <stdio.h>
#include <string.h>

int
main (int argc, char *argv[])
{
    int i, rank, size, namelen;
    char name[MPI_MAX_PROCESSOR_NAME];
    MPI_Status stat;

    MPI_Init (&argc, &argv);

    MPI_Comm_size (MPI_COMM_WORLD, &size);
    MPI_Comm_rank (MPI_COMM_WORLD, &rank);
    MPI_Get_processor_name (name, &namelen);

    if (rank == 0) {

	printf ("Hello world: rank %d of %d running on %s\n", rank, size, name);

	for (i = 1; i < size; i++) {
	    MPI_Recv (&rank, 1, MPI_INT, i, 1, MPI_COMM_WORLD, &stat);
	    MPI_Recv (&size, 1, MPI_INT, i, 1, MPI_COMM_WORLD, &stat);
	    MPI_Recv (&namelen, 1, MPI_INT, i, 1, MPI_COMM_WORLD, &stat);
	    MPI_Recv (name, namelen + 1, MPI_CHAR, i, 1, MPI_COMM_WORLD, &stat);
	    printf ("Hello world: rank %d of %d running on %s\n", rank, size, name);
	}

    } else {

	MPI_Send (&rank, 1, MPI_INT, 0, 1, MPI_COMM_WORLD);
	MPI_Send (&size, 1, MPI_INT, 0, 1, MPI_COMM_WORLD);
	MPI_Send (&namelen, 1, MPI_INT, 0, 1, MPI_COMM_WORLD);
	MPI_Send (name, namelen + 1, MPI_CHAR, 0, 1, MPI_COMM_WORLD);

    }

    MPI_Finalize ();

    return (0);
}
</code>

Compilazione:
<code>
$ module load ips-xe-2013 intel-mpi
$ mpiicc -o test test.c
</code>

==== LSF ====

Esempio di job LSF che fa utilizzo di Intel MPI:
<code bash>
#BSUB -J impi		        # Job name	
#BSUB -o %J.out			# Job standard output
#BSUB -e %J.err			# Job standard error
#BSUB -N			# Job report
#BSUB -B			# Send mail
#BSUB -q normal			# Job queue
#BSUB -a intelmpi               # Application
#BSUB -m rd-coka-02             # Host selection
#BSUB -n 10                     # Number of process
#
# commands
module load ips-xe-2013 intel-mpi
mpirun.lsf /home/GUEST/mcaberletti/test_intel_mpi/test
</code>

Salvare in un file, ad esempio ''impi.job'' e sottometterlo con:
<code bash>
$ bsub < impi.job
</code>


==== Slurm ====

Con Slurm occorre tenere presente che il comando ''sbatch'' non fa lo spawn di processi,
ma riserva solamente le risorse.
Per questo occorre indicare il numero di processi
Esempio di job:
<code bash>
#!/bin/bash
#SBATCH -J test_impi                                    # Job name
#SBATCH -p coka-test                                    # Queue
#SBATCH -e %J.err                                       # Stderr
#SBATCH -o %J.out                                       # Stdout
#SBATCH -n 10                                           # Task number
#SBATCH -w rd-coka-[01-02]                              # Host selection
#SBATCH -D /home/GUEST/mcaberletti/test_intel_mpi       # Working dir
#SBATCH --mail-type=ALL                                 # Send all notification via mail
#SBATCH --mail-user=mcaberletti@rd-ui

# commands
module load ips-xe-2013 intel-mpi
srun ./test
</code>

Salvare in un file, ad esempio ''impi.job'' e sottometterlo con:
<code bash>
$ sbatch impi.job
</code>