As a suggestion, we could just run some computation that does no system
call:

>>> import os
>>> os.times()
(0.015625, 0.015625, 0.0, 0.0, 0.0)
>>> max(xrange(10000000))   # this takes half a second on my machine
9999999
>>> os.times()
(0.015625, 0.484375, 0.0, 0.0, 0.0)

utime delta should be much higher than stime delta. This is obviously
not the case here; the values seems inverted.
   (os.times() -> (utime, stime, cutime, cstime, elapsed_time))