> I think there's basically noone and nothing (even among the buildbots)
> that runs bigmem tests on a regular basis, so I'd much rather keep the
> mmap() solution, even if that means it must be skipped on OS X.

Fair enough.

(As an aside, if it is preferable to use an mmap() hack for this sort of
test, it would be good to add some machinery to test.support to make it
easier to use. But that's something for a separate issue.)