2 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 2eb599465d56..f451fedd1e75 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -117,4 +117,23 @@ static inline enum lru_list page_lru(struct page *page)
         return lru;
 }
 
+/**
+ * inactive_anon_is_low - check if anonymous pages need to be deactivated
+ * @zone: zone to check
+ *
+ * Returns true if the zone does not have enough inactive anon pages,
+ * meaning some active anon pages need to be deactivated.
+ */
+static inline int inactive_anon_is_low(struct zone *zone)
+{
+        unsigned long active, inactive;
+
+        active = zone_page_state(zone, NR_ACTIVE_ANON);
+        inactive = zone_page_state(zone, NR_INACTIVE_ANON);
+
+        if (inactive * zone->inactive_ratio < active)
+                return 1;
+
+        return 0;
+}
 #endif
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 59a4c8fd6ebd..9c5111f49a32 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -323,6 +323,12 @@ struct zone {
          */
         int prev_priority;
 
+        /*
+         * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
+         * this zone's LRU.  Maintained by the pageout code.
+         */
+        unsigned int inactive_ratio;
+
 
         ZONE_PADDING(_pad2_)
         /* Rarely used or read-mostly fields */