On 13.07.21 12:22, Mike Rapoport wrote:
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.
I'm pushing for letting pageblocks stay untouched, so good to know!
(we still have this crazy special case of pageblocks > MAX_ORDER - 1
right now, which I think we should just eliminate)
--
Thanks,
David / dhildenb
