Re: [PATCH v2 2/3] userfaultfd: UFFDIO_REMAP uABI

Peter Xu
2023-10-03T20:22:35Z

On Tue, Oct 03, 2023 at 01:04:44PM -0700, Suren Baghdasaryan wrote:
> Ok, I think it makes sense to implement the strict remap logic but in
> a way that we can easily add copy fallback if that's needed in the
> future. So, I'll change UFFDIO_REMAP to UFFDIO_MOVE and will return
> some unique error, like EBUSY when the page is not PAE. If we need to
> add a copy fallback in the future, we will add a
> UFFDIO_MOVE_MODE_ALLOW_COPY flag and will implement the copy
> mechanism. Does that sound good?

For the clear failing approach, sounds all good here.

For the name, no strong opinion, but is there any strong one over MOVE?
MOVE is a fine name, however considering UFFDIO_REMAP's long history.. I
tend to prefer keeping it called as REMAP - it still sounds sane, and
anyone who knows REMAP will know this is exactly that.

Thanks,

--
Peter Xu