On Sat, Jun 25, 2022 at 08:59:04PM -0300, Jason Gunthorpe wrote: > On Fri, Jun 24, 2022 at 09:23:04PM -0400, Peter Xu wrote: > > If to go back to the original question with a shorter answer: if the ioctl > > context that GUP upon a page that will never be with a uffd context, then > > it's probably not gonna help at all.. at least not before we use > > FAULT_FLAG_INTERRUPTIBLE outside uffd page fault handling. > > I think I would be more interested in this if it could abort a swap > in, for instance. Doesn't this happen if it flows the interruptible > flag into the VMA's fault handler? The idea makes sense, but it doesn't work like that right now, afaict. We need to teach lock_page_or_retry() to be able to consume the flag as discussed. I don't see a major blocker for it if lock_page_or_retry() is the only one we'd like to touch. Say, the only caller currently is do_swap_page() (there's also remove_device_exclusive_entry() but just deeper in the stack). Looks doable so far but I'll need to think about it.. I can keep you updated if I get something, but it'll be separate from this patchset. Thanks, -- Peter Xu
