John Hubbard <jhubbard@xxxxxxxxxx> wrote: > I don't know how you noticed that this was even a problem! Neatly > fixed. I wanted BIO_PAGE_REFFED/PINNED to translate to FOLL_GET/PIN with no more than a single AND instruction, assuming they were assigned to the same values (1 & 2), so I checked to see what assembly was produced by: gup_flags |= bio_flagged(bio, BIO_PAGE_REFFED) ? FOLL_GET : 0; gup_flags |= bio_flagged(bio, BIO_PAGE_PINNED) ? FOLL_PIN : 0; Complicated though it looks, it should optimise down to something like: and $3,%eax assuming something like REFFED/GET == 0x1 and PINNED/PIN == 0x2. David