On 7/11/2017 11:30 PM, Nick Coghlan wrote:
Commenting more on specific technical details rather than just tone this time :)
On 11 July 2017 at 20:19, Victor Stinner <victor.stinner@gmail.com> wrote:
Reference counting may be emulated in a future implementation for backward compatibility.
One heavy user's experience with garbage collection: https://engineering.instagram.com/dismissing-python-garbage-collection-at-in... "Instagram can run 10% more efficiently. ... Yes, you heard it right! By disabling GC [and relying only on ref counting], we can reduce the memory footprint and improve the CPU LLC cache hit ratio" It turned out that gc.disable() was inadequate because imported libraries could turn it on, and one did.
I don't believe this is the best rationale to use for the PEP, as we (or at least I) have emphatically promised *not* to do another Python 3 style compatibility break, and we know from PyPy's decade of challenges that a lot of Python's users care even more about CPython C API/ABI compatibility than they do the core data model.
[snip most] -- Terry Jan Reedy