This tool is highly inspired from Brendan Greg's msr-cloud-tools (https://github.com/brendangregg/msr-cloud-tools).
First, build the readfreq binary with make.
Monitor the frequency of cpu each interval second (optionnal, defaults to 0.1s) and store results in output_dir, with some metadata:
./log_freq.sh cpu output_dir [interval]
Plot the frequency over time (output should be a .pdf, input_dir is the output_dir from the previous command):
./plot.py input_dir output
You can see the test_apps/test_loop.sh script for an exemple of how to use this tool (you will have to build the loop binary for this script to work).