On Tue, Nov 21, 2023 at 10:59:35AM -0500, Peter Xu wrote: > > What prevents us from ever using hugepd with file mappings? I think > > it would naturally fit in with how large folios for the pagecache work. > > > > So keeping this check and generalizing it seems like the better idea to > > me. > > But then it means we're still keeping that dead code for fast-gup even if > we know that fact.. Or do we have a plan to add that support very soon, so > this code will be destined to add back? The question wasn't mean retorical - we support arbitrary power of two sized folios for the pagepage, what prevents us from using hugepd with them right now? > The other option is I can always add a comment above gup_huge_pd() > explaining this special bit, so that when someone is adding hugepd support > to file large folios we'll hopefully not forget it? But then that > generalization work will only happen when the code will be needed. If dropping the check is the right thing for now (and I think the ppc maintainers and willy as the large folio guy might have a more useful opinions than I do), leaving a comment in would be very useful.
