> On Feb 22, 2023, at 4:57 PM, Axel Rasmussen <axelrasmussen@xxxxxxxxxx> wrote: > > Many userfaultfd ioctl functions take both a 'mode' and a 'wp_copy' > argument. In future commits we plan to plumb the flags through to more > places, so we'd be proliferating the very long argument list even > further. > > Let's take the time to simplify the argument list. Combine the two > arguments into one - and generalize, so when we add more flags in the > future, it doesn't imply more function arguments. > > Since the modes (copy, zeropage, continue) are mutually exclusive, store > them as an integer value (0, 1, 2) in the low bits. Place combine-able > flag bits in the high bits. > > Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Hi Axel, I sent a patch a long time ago called “userfaultfd: introduce uffd_flags”. For some reason it does not appear on lore, but you were a recipient. It was pretty similar, but one thing that I preferred in my version is that it defined a different type to avoid confusion. Since “flags” is a very generic name, perhaps you’d like to adapt this approach.