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.
