[PATCH 2/3] mm/memcg: __mem_cgroup_remove_exceeded could handle a !on-tree mz properly

[Wei Yang <richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

There is no tree operation if mz is not on-tree.

Let's remove the extra check.

Signed-off-by: Wei Yang <richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 mm/memcontrol.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d70bf5cf04eb..344a7e891bc5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -545,9 +545,11 @@ static void mem_cgroup_update_tree(struct mem_cgroup *memcg, int nid)
 			unsigned long flags;
 
 			spin_lock_irqsave(&mctz->lock, flags);
-			/* if on-tree, remove it */
-			if (mz->on_tree)
-				__mem_cgroup_remove_exceeded(mz, mctz);
+			/*
+			 * remove it first
+			 * If not on-tree, no tree ops.
+			 */
+			__mem_cgroup_remove_exceeded(mz, mctz);
 			/*
 			 * Insert again. mz->usage_in_excess will be updated.
 			 * If excess is 0, no tree ops.
-- 
2.33.1