Start working on an MPI demo

mpi_info/.gitignore

+mpi_info
+

mpi_info/Makefile

+mpi_info: mpi_info.c
+	mpicc -o $@ $<

mpi_info/load_modules.sh

+#!/bin/bash
+
+module purge
+module load spack git gcc/7.3.0 openmpi
+

mpi_info/mpi_info.c

+#include "mpi.h"
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+    int numtasks, rank, length;
+    char hostname[MPI_MAX_PROCESSOR_NAME];
+
+    MPI_Init(&argc, &argv);
+    MPI_Comm_size(MPI_COMM_WORLD, &numtasks);
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+    MPI_Get_processor_name(hostname, &length);
+    printf("Number of tasks = %d, rank = %d, running on %s\n", numtasks, rank, hostname);
+    MPI_Finalize();
+}