Differences

This shows you the differences between two versions of the page.

--- slurm [2022/05/26 14:54] – update example with CUDA version, as 9.2 is not installed on focal tdobes
+++ slurm [2025/06/30 17:59] (current) – amcguire
@@ Line 16: / Line 16: @@
 ==== Discord ====
-There is a dedicated text channel ''%%#slurm%%'' on [[https://discord.gg/ZVjX8Gv|the CS Discord server]]. Stop by and get help or help fellow Slurm users.
+There is a dedicated text channel ''%%#slurm%%'' on the UChicago CS Discord server. Please note that this Discord server is //only// for UChicago-affiliated users. You can find a link to our Discord server on the [[start|front page]] of this wiki.
 ===== Clusters =====
@@ Line 27: / Line 27: @@
 ==== Peanut Cluster ====
-Think of these machines as a dumping ground for discrete computing tasks that might be rude or disruptive to execute on the main (shared) shell servers (i.e., linux1, linux2, linux3).
+Think of these machines as a dumping ground for discrete computing tasks that might be rude or disruptive to execute on the main (shared) shell servers (i.e., ''focal0'', ''focal1'', ..., ''focal7'').
 Additionally, this cluster is used for courses that require it.
@@ Line 39: / Line 39: @@
 ===== Where to begin =====
-Slurm is a set of command line utilities that can be accessed via the command line from **most** any computer science system you can login to. Using our main shell servers (linux.cs.uchicago.edu) is expected to be our most common use case, so you should start there.
+Slurm is a set of command line utilities that can be accessed via the command line from **most** any computer science system you can login to. Using our main shell servers (''linux.cs.uchicago.edu'') is expected to be our most common use case, so you should start there.
   ssh user@linux.cs.uchicago.edu
@@ Line 88: / Line 88: @@
 === Default Quotas ===
 By default we set a job to be run on one CPU and allocate 100MB of RAM. If you require more than that you should specify what you need. Using the following options will do: ''%%--mem-per-cpu%%'', ''%%--nodes%%'', ''%%--ntasks%%''.
+=== MPI Usage ===
+The AI cluster supports the use of MPI. The following example illustrates its basic use.
+<code>
+amcguire@fe01:~$ cat mpi-hello.c
+#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();
+}
+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
+# Disable the Infiniband transport for OpenMPI (not present on all clusters)
+#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
+amcguire@fe01:~$ sbatch -w p001,p002 -p peanut-cpu hello-job.sh
+Submitted batch job 1196702
+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>
 === Exclusive access to a node ===
@@ Line 415: / Line 469: @@
 STDOUT will look something like this:
 <code>
-cnetid@linux1:~$ cat $HOME/slurm/slurm_out/12567.gpu1.stdout
+cnetid@focal0:~$ cat $HOME/slurm/slurm_out/12567.gpu1.stdout
 Device Number: 0
   Device name: Tesla M2090