From 215e24fc44a6d7ace4bc97a6370af79f22e1146a Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Date: Wed, 7 Jan 2009 18:08:23 -0800
Subject: [PATCH] --- yaml --- r: 127591 b: refs/heads/master c:
 2733c06ac864ed40b9dfbbd5270f3f16949bd4a1 h: refs/heads/master i:   127589:
 f94b28305b4f4be0e68ea2442962054a9567d3b9   127587:
 cd22988cede1415d148a6e23e919841d989e2b89   127583:
 9b29fff0a8cbd95b45d82c5aa83731472849841d v: v3

---
 [refs]                |  2 +-
 trunk/mm/memcontrol.c | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index ad0ed7bef97d..d3defa4e4254 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e72e2bd6747c7a5c432197b6614cf3a387e61a0e
+refs/heads/master: 2733c06ac864ed40b9dfbbd5270f3f16949bd4a1
diff --git a/trunk/mm/memcontrol.c b/trunk/mm/memcontrol.c
index af28e128b749..027c0dd7a83e 100644
--- a/trunk/mm/memcontrol.c
+++ b/trunk/mm/memcontrol.c
@@ -144,6 +144,11 @@ struct mem_cgroup {
 	 */
 	struct mem_cgroup_lru_info info;
 
+	/*
+	  protect against reclaim related member.
+	*/
+	spinlock_t reclaim_param_lock;
+
 	int	prev_priority;	/* for recording reclaim priority */
 
 	/*
@@ -400,18 +405,28 @@ int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
  */
 int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
 {
-	return mem->prev_priority;
+	int prev_priority;
+
+	spin_lock(&mem->reclaim_param_lock);
+	prev_priority = mem->prev_priority;
+	spin_unlock(&mem->reclaim_param_lock);
+
+	return prev_priority;
 }
 
 void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
 {
+	spin_lock(&mem->reclaim_param_lock);
 	if (priority < mem->prev_priority)
 		mem->prev_priority = priority;
+	spin_unlock(&mem->reclaim_param_lock);
 }
 
 void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
 {
+	spin_lock(&mem->reclaim_param_lock);
 	mem->prev_priority = priority;
+	spin_unlock(&mem->reclaim_param_lock);
 }
 
 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
@@ -2076,6 +2091,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 	}
 	mem_cgroup_set_inactive_ratio(mem);
 	mem->last_scanned_child = NULL;
+	spin_lock_init(&mem->reclaim_param_lock);
 
 	return &mem->css;
 free_out: