1 files changed, 13 insertions, 0 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 71a58f67f481..bd939a574b84 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -313,6 +313,19 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
                 } else if (!locked)
                         spin_lock_irq(&zone->lru_lock);
 
+                /*
+                 * migrate_pfn does not necessarily start aligned to a
+                 * pageblock. Ensure that pfn_valid is called when moving
+                 * into a new MAX_ORDER_NR_PAGES range in case of large
+                 * memory holes within the zone
+                 */
+                if ((low_pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+                        if (!pfn_valid(low_pfn)) {
+                                low_pfn += MAX_ORDER_NR_PAGES - 1;
+                                continue;
+                        }
+                }
+
                 if (!pfn_valid_within(low_pfn))
                         continue;
                 nr_scanned++;