Hi there, I seem to be running into a problem with freeing memory. Under OS X all is well, but under Linux there seems to be a problem in the case of linked data structures. I have attached a python program which demonstrates the problem. The output of the script for both linux and OS X are below. Thanks very much in advance, and for the amazing work on PyPy. OS X: 2.7.8 (857f34cd4254, Oct 14 2014, 22:01:17) [PyPy 2.5.0-alpha0 with GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.51)] Darwin 14.1.0 ('', '', '') initial 20 MB 0 558 MB 0 30 MB 1 558 MB 1 31 MB 2 558 MB 2 32 MB Linux: 2.7.8 (dfffd5d7cc7e, Feb 08 2015, 14:59:48) [PyPy 2.5.0 with GCC 4.8.2] Linux 3.13.0-44-generic ('debian', 'jessie/sid', '') initial 82 MB 0 626 MB 0 626 MB 1 627 MB 1 627 MB 2 627 MB 2 627 MB