On Mon, Mar 15, 2021 at 02:55:01PM +0300, Kirill A. Shutemov wrote: > I'm with Matthew on this. I would really want to drop the number of places > where we call compoud_head(). I hope we can get rid of the page flag > policy hack I made. I can't see that far ahead too clearly, but I do think that at some point we'll actually distinguish between folio flags and page flags. For example, we won't have a FolioHWPoison, because we won't keep a folio together if one page in it has become defective. Nor will we have a PageUptodate because we'll only care about whether a folio is uptodate. And at that point, we won't want page flag policies.