On Thu, Sep 09, 2021 at 10:17:14AM -0700, Linus Torvalds wrote: > So I think we should treat FOLL_FAST_ONLY as a special "internal to > gup.c" flag, and perhaps not really compare it to the new > FOLL_NOFAULT. > > In fact, maybe we could even just make FOLL_FAST_ONLY be the high bit, > and not expose it in <linux/mm.h> and make it entirely private as a > name in gup.c. There are quite a few bits like that. I've been wanting to make them private for 5.16.