--- Comment #9 from Mark Johnston <[hidden email]> ---
(In reply to David Chisnall from comment #8)
MADV_FREE has no effect on shared memory (or anything other than private
anonymous memory); see vm_object_advice_applies(). We should update the man
page to that effect.
Aside from emulating Linux's MADV_DONTNEED, I'm not crazy about following the
precedent set by Linux by adding a MADV_ZERO that is required to have specific
side effects. msync(2) might be a better entry point for this functionality?