mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block during...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / compaction.c

diff --git a/mm/compaction.c b/mm/compaction.c
index 71a58f6..bd939a5 100644 (file)
--- 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++;