[PATCH] [RT] avoid preemption in memory controller code

[Tim Blechmann <tim@klingt.org>]

the lru_lock of struct mem_group_per_zone is used to avoid preemption
during the __mem_cgroup_stat_add_safe function.
therefore, a raw_spinlock_t should be used.

Signed-off-by: Tim Blechmann <tim@klingt.org>
---
 mm/memcontrol.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 517f945..8661732 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -95,9 +95,9 @@ enum mem_cgroup_zstat_index {
 
 struct mem_cgroup_per_zone {
 	/*
-	 * spin_lock to protect the per cgroup LRU
+	 * raw_spin_lock to protect the per cgroup LRU
 	 */
-	spinlock_t		lru_lock;
+	raw_spinlock_t		lru_lock;
 	struct list_head	active_list;
 	struct list_head	inactive_list;
 	unsigned long count[NR_MEM_CGROUP_ZSTAT];
-- 
1.5.6.3