clocking subprocesses

[barnburnr at gmail.com]

Hi,

I've seen several threads on this subject, but haven't (yet) run
across one that answers my specific questions.  This should be really
easy for someone, so here goes:

I'm running some numerical simulations under Ubuntu, and using Python
as my scripting language to automatically manage input and output.  I
need to have a precise performance measurement (CPU time) of how long
it takes to run my simulations.

Right now I have something like:

stime = time.time()
subprocess.call(["./mysim","args"])
ftime = time.time()
print ftime-stime

However, time.time() only gives wall-clock time, so I'm also measuring
the time it takes to run other processes running at the same time.
What I'd rather have is:

stime = time.clock()
subprocess.call(["./mysim","args"])
ftime = time.clock()
print ftime-stime

But this, of course, usually outputs 0, because time.clock() does not
count the CPU ticks of the subprocess.

So, long story short, I need to get CPU time of something I call using
subprocess.call().  I don't want to have to profile my code, since it
will significantly reduce computation time.

Thanks for the advice.

Kevin