On Thu, Feb 06, 2020 at 06:57:41PM +0200, Mike Rapoport wrote: > While updating the architectures to properly use 5-level folded page tables > without <asm-generic/?level-fixup.h> and <asm-generic/pgtable-nop4d-hack.h> > I wondered if we can do better than explicitly name each and every level of > the page table, open-code traversal of all the layers numerous times and > have copied do_something_pXd_range(). > > Then I've come across Kirill's "Proof-of-concept: better(?) page-table > manipulation API" [1], but as far as I could see there was no progress > since then. > > I'd like to resurrect the topic and try to see if we can come up with > actually better page table manipulation API. > > [1] https://lore.kernel.org/lkml/20180424154355.mfjgkf47kdp2by4e@xxxxxxxxxxxxxxxxxx/ I don't think this approach helps support 64k pages on ARM, for example, so it doesn't solve enough problems to be worth doing. I'd favour an interface which looked more like this: vpte_iter iter; vpte_t vpte; vpte_iter_for_each(vpte, iter, start, end, flags) { unsigned char order = vpte_order(&iter); ... do things based on vpte and order ... }
