Issue using Matplotlib with X-server

[coleramos425]

This seems to be an issue that only occurs when you are connected via ssh to a system that has an X-server running.

https://github.com/AMDResearch/omniperf/blob/796c495d0b41bb63f62220278bd4fdca323a463b/src/utils/plot_roofline.py#L31

The reason being that when an X-server is running, matplotlib, by default, tries to connect but can't and so he throws fatal exceptions.

Suggested Fix

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

the use('Agg') call sets matplotlib to use the non-interactive backend that can only write to files. This is apparently required if you happen to run omniperf on a system with X running.

CC: @keithloweryamd

[jrmadsen]

import matplotlib

try:
    import matplotlib.pyplot as plt
except ImportError:
    # other non-interactive options: 
    #   cairo, pdf, pgf, ps, svg, template
    matplotlib.use("agg", force=True)
    import matplotlib.pyplot as plt
    

[jrmadsen]

The benefit of the above approach is that different backends produce different quality plots and pyplot usually tries to set the best one. This way, you don't lose that while still allowing the user can set the "MPLBACKEND" environment variable to select the one they want. But the try-except should handle your error

[coleramos425]

Thanks for the suggestion @jrmadsen. Added this to dev branch.