[scottlamb]

> It does make me wonder why pymallov and jemalloc used page aligned memory, but glibc didn't. That is odd.

Other way around: with glibc it was page-aligned; with the others, it wasn't.

This weird Zen performance quirk aside, I'd prefer page alignment so that an allocation like this which is a nice multiple of the page size doesn't waste anything (RAM or TLB), with the memory allocator's own bookkeeping in a separate block. Pretty surprising to me that the other allocators do something else.