mem_test.py

# A simple script to test memory allocation/deallocation in Python
#
# When run under Win32 with Python 2.6.2 (r262:71605, Apr 14 2009, 22:40:02)
# [MSC v.1500 32 bit (Intel)]
# it will after each allocation release all memory back the OS.
#
# However, when run under Linux/RHEL5 with
# Python 2.6 (r26:66714, Jun 15 2009, 17:33:43)
# [GCC 4.1.2 20071124 (Red Hat 4.1.2-42)]
# it never releases the memory again, thus eating more and more memory.
#
# Is this really the intended behavior of CPython?
# Or is this due to the underlying memory management of each OS/library?

import gc, time, os, sys

print "PID is", os.getpid()
print "Press Enter to start test"
raw_input()

class X(object):
	def __init__(self):
		self.foo = None

def ints(n):
	print "Allocating %d tuples with 3 integers..." % n
	x = [(23, 34, 2523) for i in xrange(n)]

def objects(n):
	print "Allocating %d objects..." % n
	x = [X() for i in xrange(n)]

size = 1000000
tests = [objects, objects]
for f in tests:
	f(size)
	print "Done. View process resources with top or similar."
	print "Press Enter to continue"
	raw_input()

print "Forcing GC collect..."
gc.collect()
print "Press Enter to exit"
raw_input()