On Thu, Jan 7, 2021 at 2:03 PM Andrea Arcangeli <aarca...@redhat.com> wrote: > > If you could stop mentioning UFFDIO_WRITEPROTECT and only focus on > softdirty/clear_refs, maybe you wouldn't think my judgment is biased > towards clear_refs/softdirty too.
So I think we can agree that even that softdirty case we can just handle by "don't do that then". if a page is pinned, the dirty bit of it makes no sense, because it might be dirtied complately asynchronously by the pinner. So I think none of the softdirty stuff should touch pinned pages. I think it falls solidly under that "don't do it then". Just skipping over them in clear_soft_dirty[_pmd]() doesn't look that hard, does it? Linus