On Wed, Nov 22, 2023 at 12:00:24AM -0800, Christoph Hellwig wrote: > > 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. It looks like ARM (in the person of Ryan) are going to add support for something equivalent to hugepd. Insofar as I understand hugepd, anyway. I've done my best to set up the generic code so that the arch code can use whatever size TLB entries it supports. I haven't been looking to the hugetlb code as a reference for it, since it can assume natural alignment and generic THP/large folio must be able to handle arbitrary alignment. If powerpc want to join in on the fun, they're more than welcome, but I get the feeling that investment in Linux-on-PPC is somewhat smaller than Linux-on-ARM these days. Even if we restrict that to the server space.
