initial commit

COMP  = cc

FLAGS = -fopenmp

hello_mpi_omp: hello_mpi_omp.o

	${COMP} ${FLAGS} hello_mpi_omp.o -o hello_mpi_omp

hello_mpi_omp.o: hello_mpi_omp.c

	${COMP} ${FLAGS} -c hello_mpi_omp.c

PHONY: clean

clean:

	rm -f hello_mpi_omp *.o

/* -------------------------------------------------------------

MPI + OpenMP Hello, World program to help understand process

and thread mapping to physical CPU cores and hardware threads

------------------------------------------------------------- */

#define _GNU_SOURCE

#include <stdio.h>

#include <mpi.h>

#include <sched.h>

#include <omp.h>

int main(int argc, char *argv[]){

	MPI_Init(&argc, &argv);

	int size;

	MPI_Comm_size(MPI_COMM_WORLD, &size);

	int rank;

	MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    char name[MPI_MAX_PROCESSOR_NAME];

    int resultlength;

    MPI_Get_processor_name(name, &resultlength);

    int hwthread;

    int thread_id = 0;

    #pragma omp parallel default(shared) private(hwthread, thread_id)

    {

        thread_id = omp_get_thread_num();

        hwthread  = sched_getcpu();

        printf("MPI %03d - OMP %03d - HWT %03d - Node %s\n", rank, thread_id, hwthread, name);

    }

	MPI_Finalize();

	return 0;

}