Benchmarking program for scalar mpi reductions, and nonbatch script for running benchmarks

- New program mpi_reduce_bench
      - runs testcases defined in source
      - writes all benchmark results to a csv file, tags the testcase and benchmark run
      - takes optional argument for benchmark tag, default benchmark tag is a timestamp
    - New script mpibench.sh
      - runs the mpi_reduce_bench with defined parameters:
        - number of tasks
        - number of nodes
        - the benchmark tag for mpi_reduce_bench, default tag is the current git HEAD short hash

samples/mpi_reduce_bench/mpibench.sh

@@ -0,0 +1,63 @@
+#!/bin/bash
+
+#defaults
+default_num_procs=8
+default_num_nodes=2
+
+num_procs=$default_num_procs
+num_nodes=$default_num_nodes
+
+script_name=$0
+
+print_usage(){
+    echo "Usage: $script_name [Options]"
+    echo "\tRuns mpi_reduce_bench, which will write benchmark results"
+    echo "Options:"
+    echo "\t -n <num_procs>"
+    echo "\t\t-n option to slurm, default=$default_num_procs"
+    echo "\t -N <num_nodes>"
+    echo "\t\t-N option to slurm, default=$default_num_nodes"
+    echo "\t -t <tag>"
+    echo "\t\tA benchmark tag that will be added to the mpi_reduction_benchmark.csv file"
+    echo "\t\tBy default the current git HEAD short hash will be used as a tag"
+}
+
+while getopts n:N:t: opt
+do
+    case "$opt" in
+        n)
+            if [ $OPTARG ]
+            then
+                num_procs=$OPTARG
+            else
+                print_usage
+                exit 1
+            fi
+        ;;
+        N)
+            if [ $OPTARG ]
+            then
+                num_nodes=$OPTARG
+            else
+                print_usage
+                exit 1
+            fi
+        ;;
+        t)
+            if [ $OPTARG ]
+            then
+                benchmark_label=$OPTARG
+            else
+                print_usage
+                exit 1
+            fi
+        ;;
+    esac
+done
+
+if [ -z "$benchmark_label" ]
+then
+    benchmark_label=$(git rev-parse --short HEAD)
+fi
+set -x
+srun --account=project_2000403 --gres=gpu:v100:4 --mem=48000 -t 00:14:59 -p gpu -n ${num_procs} -N ${num_nodes} ./mpi_reduce_bench ${benchmark_label}