Even with cPickle?
AFAIR: Yes. It was not orders of magnitude slower anymore, but significantly slower.
I'm still worried about your patch, because it changes all uses of marchal, not just how code objects are marshalled. The marshal module *is* used by other apps...
The change is backwards-compatible in the sense that existing files can be unmarshalled just fine. Problems will only arise if new marshal output is unmarshalled by old versions, which could be solved with an option during marshalling. Regards, Martin