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If we have a writable PTE then while the PTE's PTL is held it is impossible for a FS to make the page clean as any cleaning action has to also take the PTL to make the PTE non-present or non-writable. > If we want to be more adventerous the opt-in variant could default to on > for FOLL_LONGTERM too, but that discussion can be had over on that patch > series. I think you should at least do this too to explain why io_uring code is moving into common code.. Jason