Differences

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--- slurm [2025/06/30 10:57] – amcguire
+++ slurm [2025/06/30 17:59] (current) – amcguire
@@ Line 93: / Line 93: @@
 <code>
-(base) amcguire@fe01:~$ cat mpi-hello.c
+amcguire@fe01:~$ cat mpi-hello.c
 #include <mpi.h>
 #include <unistd.h>
@@ Line 120: / Line 120: @@
     MPI_Finalize();
 }
+amcguire@fe01:~$ cat hello-job.sh
+#!/bin/bash
+#SBATCH -J mpi-hello            # Job name
+#SBATCH -n 2                    # Number of processes
+#SBATCH -t 0:10:00              # Max wall time
+#SBATCH -o hello-job.out        # Output file name
-(base) amcguire@fe01:~$ mpicc -o mpi-hello mpi-hello.c
+# Disable the Infiniband transport for OpenMPI (not present on all clusters)
-(base) amcguire@fe01:~$ ls -l mpi-hello
+#export OMPI_MCA_btl="^openib"
+# Run the job (assumes the batch script is submitted from the same directory)
+mpirun -np 2 ./mpi-hello
+amcguire@fe01:~$ mpicc -o mpi-hello mpi-hello.c
+amcguire@fe01:~$ ls -l mpi-hello
 -rwxrwx--- 1 amcguire amcguire 16992 Jun 30 10:49 mpi-hello
-(base) amcguire@fe01:~$ sbatch -w p001,p002 -p peanut-cpu hello-job.sh
+amcguire@fe01:~$ sbatch -w p001,p002 -p peanut-cpu hello-job.sh
 Submitted batch job 1196702
-(base) amcguire@fe01:~$ cat hello-job.out
+amcguire@fe01:~$ cat hello-job.out
 Hello from process 0 of 2 on host p001
 Hello from process 1 of 2 on host p002
 </code>
-For convenience, you may download the files used here.
-<file>
-#include <mpi.h>
-#include <unistd.h>
-#include <stdio.h>
-int main(int argc, char **argv) {
-    // Initialize MPI
-    MPI_Init(&argc, &argv);
-    // Get the number of processes in the global communicator
-    int count;
-    MPI_Comm_size(MPI_COMM_WORLD, &count);
-    // Get the rank of the current process
-    int rank;
-    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
-    // Get the current hostname
-    char hostname[1024];
-    gethostname(hostname, sizeof(hostname));
-    // Print a hello world message for this rank
-    printf("Hello from process %d of %d on host %s\n", rank, count, hostname);
-    // Finalize the MPI environment before exiting
-    MPI_Finalize();
-}
-</file>
 === Exclusive access to a node ===
 You will need to add the ''%%--exclusive%%'' options to your script or command line options. This option will ensure that when your job runs it is the only job running on that particular node.