[PATCH 6/8] mm: page_isolation: Handle unaccepted memory isolation

[Kirill A. Shutemov]

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.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 mm/page_isolation.c | 8 ++++++++
 1 file changed, 8 insertions(+)

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);
 
-- 
2.43.0