On Tue, Jul 13, 2021 at 11:51:46AM +0200, David Hildenbrand wrote: > On 13.07.21 10:00, Mike Rapoport wrote: > > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > > > After recent changes in freeing of the unused parts of the memory map and > > rework of pfn_valid() in arm and arm64 there are no architectures that can > > have holes in the memory map within a pageblock and so nothing can enable > > CONFIG_HOLES_IN_ZONE which guards non trivial implementation of > > pfn_valid_within(). > > > > With that, pfn_valid_within() is always hardwired to 1 and can be > > completely removed. > > > > Remove calls to pfn_valid_within() and CONFIG_HOLES_IN_ZONE. > > > > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > There is currently the discussion to increase MAX_ORDER, for example, to > cover 1GiB instead of 4MiB on x86-64. This would mean that we could > suddenly, again, have holes insides MAX_ORDER - 1 pages. > > So I assume if we ever go down that path, we'll need something like this > again. It depends whether pageblock_order will be also increased. PFN walkers rely on continuity of pageblocks rather than MAX_ORDER chunks, so if pageblock_order won't change, there won't be need to check for pfn_valid() inside a pageblock. > For now, this looks like the right thing to do > > Acked-by: David Hildenbrand <david@xxxxxxxxxx> Thanks! -- Sincerely yours, Mike.
