1 files changed, 41 insertions, 0 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 740a16a32c22..79c0981b1d32 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4263,6 +4263,46 @@ void setup_per_zone_pages_min(void)
         calculate_totalreserve_pages();
 }
 
+/**
+ * setup_per_zone_inactive_ratio - called when min_free_kbytes changes.
+ *
+ * The inactive anon list should be small enough that the VM never has to
+ * do too much work, but large enough that each inactive page has a chance
+ * to be referenced again before it is swapped out.
+ *
+ * The inactive_anon ratio is the target ratio of ACTIVE_ANON to
+ * INACTIVE_ANON pages on this zone's LRU, maintained by the
+ * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of
+ * the anonymous pages are kept on the inactive list.
+ *
+ * total     target    max
+ * memory    ratio     inactive anon
+ * -------------------------------------
+ *   10MB       1         5MB
+ *  100MB       1        50MB
+ *    1GB       3       250MB
+ *   10GB      10       0.9GB
+ *  100GB      31         3GB
+ *    1TB     101        10GB
+ *   10TB     320        32GB
+ */
+void setup_per_zone_inactive_ratio(void)
+{
+        struct zone *zone;
+
+        for_each_zone(zone) {
+                unsigned int gb, ratio;
+
+                /* Zone size in gigabytes */
+                gb = zone->present_pages >> (30 - PAGE_SHIFT);
+                ratio = int_sqrt(10 * gb);
+                if (!ratio)
+                        ratio = 1;
+
+                zone->inactive_ratio = ratio;
+        }
+}
+
 /*
  * Initialise min_free_kbytes.
  *
@@ -4300,6 +4340,7 @@ static int __init init_per_zone_pages_min(void)
                 min_free_kbytes = 65536;
         setup_per_zone_pages_min();
         setup_per_zone_lowmem_reserve();
+        setup_per_zone_inactive_ratio();
         return 0;
 }
 module_init(init_per_zone_pages_min)