On Thu, Apr 09, 2020 at 05:28:51PM +0300, Kirill A. Shutemov wrote: > > We have a few places that do things like > > > > mm/filemap.c: if (unlikely(compound_head(page)->mapping != mapping)) { > > Good point. > > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Darn, I hoped you'd have a better idea. I feel quite ashamed of this patch.