Mostly used to stop CUDA ML model training from making my desktop
unusable. Simply monitors keyboard/mouse idleness using xprintidle,
and pauses the given process using SIGSTOP whenever the machine is
in use (defined as no activity within the last second).
Invoke either with a command,
lazy ./train_my_gpu_intensive_model.py
or with a PID of something already running.
lazy -p 1234
(In PID mode, lazy is likely to leave the process paused after
exiting, if cancelled with ^C. Resume it manually with kill -SIGCONT $PID, or fg in the shell you originally started it in.)