On 18.12.21 03:42, Linus Torvalds wrote: > On Fri, Dec 17, 2021 at 6:17 PM Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: >> >> I think the hugepage code should use the exact same logic that the >> regular wp fault code does. > > IOW, I think that this stupid (AND UNTESTED) patch should likely just > fix David's test-case with the hugepage and splice thing.. > > Or at least be somewhat close. But it should be paired with the GUP > side doing the right thing too, of course. Maybe it already does, > maybe it doesn't, I didn't check... > > And maybe there's something subtle about the page_count() of a THP > entry. Again, I can't really claim to have tested this all, but I'm > hoping this makes somebody go "Ahh, now I see what Linus means" Not the reaction you are hoping for: "Gah, Linus still doesn't see why the page_count is just wrong". :) See the mail I just wrote, let's get a common understanding of how our check should actually look like. -- Thanks, David / dhildenb
