mm: page_isolation: handle unaccepted memory isolation

Page isolation machinery doesn't know anything about unaccepted memory and
considers it non-free.  It leads to alloc_contig_pages() failure.

Treat unaccepted memory as free and accept memory on pageblock isolation. 
Once memory is accepted it becomes PageBuddy() and page isolation knows
how to deal with them.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kirill A.  Shutemov <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Johannes Weiner <[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]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 042937d5abe4..39fb8c07aeb7 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -152,6 +152,9 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_
 	unsigned long flags;
 	unsigned long check_unmovable_start, check_unmovable_end;
 
+	if (PageUnaccepted(page))
+		accept_page(page);
+
 	spin_lock_irqsave(&zone->lock, flags);
 
 	/*
@@ -367,6 +370,11 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
 		VM_BUG_ON(!page);
 		pfn = page_to_pfn(page);
 
+		if (PageUnaccepted(page)) {
+			pfn += MAX_ORDER_NR_PAGES;
+			continue;
+		}
+
 		if (PageBuddy(page)) {
 			int order = buddy_order(page);