Re: [PATCH v4 1/4] mm/shmem: Unconditionally set pte dirty in mfill_atomic_install_pte

[Andrew Morton]

On Tue, 28 Sep 2021 17:37:31 -0400 Peter Xu <peterx@xxxxxxxxxx> wrote:

> > How about a compromise (if you really want to continue with this patch):
> > you leave the SetPageDirty(page) in shmem_mfill_atomic_pte(), where I
> > feel a responsibility for it; but you do whatever works for you with
> > pte_mkdirty() at the mm/userfaultfd.c end?
> 
> Sure.  Duplicating dirty bit is definitely fine to me as it achieves the same
> goal as I hoped - we're still 100% clear we won't free a uffd page without
> being noticed, then that's enough to me for the goal of this patch.  I won't
> initiate that NACK myself since I still think duplicating is unnecessary no
> matter it resides in shmem or uffd code, but please go ahead doing that and
> I'll be fine with it, just in case Andrew didn't follow the details.

I think Hugh was asking you to implement this...

I guess I'll send this patch upstream.  But it does sound like Hugh
would prefer a followon patch for this kernel release which makes the
above change, please.