---

yaml
---
r: 272163
b: refs/heads/master
c: e0887c1
h: refs/heads/master
i:
  272161: d8b70a3
  272159: 0cc1f87
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 21ee9f398be209ccbb62929d35961ca1ed48eec3
+refs/heads/master: e0887c19b2daa140f20ca8104bdc5740f39dbb86

trunk/mm/vmscan.c

@@ -2125,6 +2125,22 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
 				continue;
 			if (zone->all_unreclaimable && priority != DEF_PRIORITY)
 				continue;	/* Let kswapd poll it */
+			if (COMPACTION_BUILD) {
+				/*
+				 * If we already have plenty of memory
+				 * free for compaction, don't free any
+				 * more.  Even though compaction is
+				 * invoked for any non-zero order,
+				 * only frequent costly order
+				 * reclamation is disruptive enough to
+				 * become a noticable problem, like
+				 * transparent huge page allocations.
+				 */
+				if (sc->order > PAGE_ALLOC_COSTLY_ORDER &&
+					(compaction_suitable(zone, sc->order) ||
+					 compaction_deferred(zone)))
+					continue;
+			}
 			/*
 			 * This steals pages from memory cgroups over softlimit
 			 * and returns the number of reclaimed pages and