This is a small and simple test of using OpenMP on systems with GNU compiler. It's a console-only C program that estimates values of pi. The gcc compiler and openmp libraries are required. It was developed on Centos 6.
C code by John Burkardt was taken from https://people.sc.fsu.edu/~jburkardt/c_src/prime_openmp/prime_openmp.html who has a fantastic collection of example parallel codes in several languages.
For those new to OpenMP, you may compile as follows:
gcc -o prime_openmp -fopenmp prime_openmp.c
#then do a test run
echo current thread count = $OMP_NUM_THREADS
echo -------------
./prime_openmp
See the script thread_test.sh for an example of looping through values of $OPM_NUM_THEADS to show performance improvements as threads increase.
bash thread_test.sh