diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2f644c3e3da378baf0f186cb406e717b20ad4932..ce2a026219bc84ee40f1ed5311025de55891d0ad 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3381,10 +3381,8 @@ static void __init setup_usemap(struct pglist_data *pgdat,
 {
 	unsigned long usemapsize = usemap_size(zonesize);
 	zone->pageblock_flags = NULL;
-	if (usemapsize) {
+	if (usemapsize)
 		zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
-		memset(zone->pageblock_flags, 0, usemapsize);
-	}
 }
 #else
 static void inline setup_usemap(struct pglist_data *pgdat,