From 8323fc3e938268b8f5024633f0d09f5d2ec0be72 Mon Sep 17 00:00:00 2001
From: Rik van Riel <riel@redhat.com>
Date: Mon, 31 Oct 2011 17:09:31 -0700
Subject: [PATCH] --- yaml --- r: 272163 b: refs/heads/master c:
 e0887c19b2daa140f20ca8104bdc5740f39dbb86 h: refs/heads/master i:   272161:
 d8b70a316c53c29df739f1f4234c00a7712933fb   272159:
 0cc1f8764815bf24572a53dafb3275883f04c9de v: v3

---
 [refs]            |  2 +-
 trunk/mm/vmscan.c | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 710873c004fc..6283e9939409 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 21ee9f398be209ccbb62929d35961ca1ed48eec3
+refs/heads/master: e0887c19b2daa140f20ca8104bdc5740f39dbb86
diff --git a/trunk/mm/vmscan.c b/trunk/mm/vmscan.c
index f51a33e8ed89..7e0f05797388 100644
--- a/trunk/mm/vmscan.c
+++ b/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