Re: [RFC, PATCH 00/12] userfaultfd: working set tracking for VM guest memory

David Hildenbrand (Arm)
2026-04-23T19:25:37Z

>
> The other thing is, as I mentioned in the other email, I still don't know
> how the current RW protection would work for anonymous. I don't yet think
> the user swapper can read the anon page with RW-protected pgtables. So far
> my understanding is maybe you only care about shmem so it's fine, but it'll
> always be great to confirm with you.

I wonder if uffdio_move could be used for a swapper implementation instead?

If we ever have to read from a protnone page, maybe we could teach ptrace access
to do it, or have something that can read from prot_none areas -- like
uffdio_copy, which can write to prot-none areas.

--
Cheers,

David