The volatile volatile ranges patch set

From a (this at least) user space developer perspective, madvise() sounds like the interface that fits best the proposed behavior.

But for the sake of clarity I would prefer it to be called MADV_FREEABLE (volatile is also a C keyword with very different semantics). In fact, I think the best flag names would be MADV_FREETRYREMEMBER and MADV_TRYRECALL.