diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b88e6ad7eb08..48b32a573f10 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2919,10 +2919,11 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
 	unsigned long max_managed, flags;
 
 	/*
-	 * Limit the number reserved to 1 pageblock or roughly 1% of a zone.
+	 * The number reserved as: minimum is 1 pageblock, maximum is
+	 * roughly 1% of a zone.
 	 * Check is race-prone but harmless.
 	 */
-	max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;
+	max_managed = ALIGN((zone_managed_pages(zone) / 100), pageblock_nr_pages);
 	if (zone->nr_reserved_highatomic >= max_managed)
 		return;