Hi all, I've been trying to learn about how PyPy supports (unmodified) Python extensions, and one thing I've heard is that it's much slower than cPython, and/or uses more memory.  I tried finding some documentation about why, and all I could find is this, from 2010:

Sorry if this should be obvious, but is there more up-to-date information about this stuff?  And secondly, assuming the info that I linked to is still valid, is there a reason you guys settled on this method of bridging the refcount/tracing divide, as opposed to other possibilities (can you pin the objects in the GC)?

I'm curious, since I've heard a number of people mention that extension modules are the primary reason that PyPy is slower than cPython for their code; definitely an improvement over "PyPy doesn't run my code at all", but it's made me curious about whether or not / why it has to be that way.