Exiting os.spawnv's subroutine

[IamIan]

I am using os.spawnv in Python 2.1 to do some geoprocessing in a
subroutine/process. Everything works great, except when the processing
is done the subroutine just waits for a couple minutes before closing
itself and returning to the main script. I have tried using sys.exit()
and exit() but these aren't doing anything.

What is the proper way to terminate this subroutine upon completion,
rather than waiting? Thank you.