mm: fix endless reclaim on machines with unaccepted memory

Unaccepted memory is considered unusable free memory, which is not counted
as free on the zone watermark check.  This causes get_page_from_freelist()
to accept more memory to hit the high watermark, but it creates problems
in the reclaim path.

The reclaim path encounters a failed zone watermark check and attempts to
reclaim memory.  This is usually successful, but if there is little or no
reclaimable memory, it can result in endless reclaim with little to no
progress.  This can occur early in the boot process, just after start of
the init process when the only reclaimable memory is the page cache of the
init executable and its libraries.

Make unaccepted memory free from watermark check point of view.  This way
unaccepted memory will never be the trigger of memory reclaim.  Accept
more memory in the get_page_from_freelist() if needed.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory")
Signed-off-by: Kirill A. Shutemov <[email protected]>
Reported-by: Jianxiong Gao <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Tested-by: Jianxiong Gao <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Mike Rapoport (Microsoft) <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: <[email protected]>	[6.5+]
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions