1 files changed, 14 insertions, 2 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index d572b78b65e1..7f2ae99e5daf 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -828,9 +828,21 @@ unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
  */
 #define zone_idx(zone)          ((zone) - (zone)->zone_pgdat->node_zones)
 
-static inline int populated_zone(struct zone *zone)
+/*
+ * Returns true if a zone has pages managed by the buddy allocator.
+ * All the reclaim decisions have to use this function rather than
+ * populated_zone(). If the whole zone is reserved then we can easily
+ * end up with populated_zone() && !managed_zone().
+ */
+static inline bool managed_zone(struct zone *zone)
+{
+        return zone->managed_pages;
+}
+
+/* Returns true if a zone has memory */
+static inline bool populated_zone(struct zone *zone)
 {
-        return (!!zone->present_pages);
+        return zone->present_pages;
 }
 
 extern int movable_zone;