[PATCH] mm, memcg: fix comment error about memory.low usage

[Xu Yu <xuyu@linux.alibaba.com>]

When memory.current > memory.low, the usage of memory.low should be the
value of memory.low, not 0.

Fix and simplify the equation in comments.

Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
---
 mm/memcontrol.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c5b5f74..def95a5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6236,9 +6236,7 @@ struct cgroup_subsys memory_cgrp_subsys = {
  * elow = min( memory.low, parent->elow * ------------------ ),
  *                                        siblings_low_usage
  *
- *             | memory.current, if memory.current < memory.low
- * low_usage = |
- *	       | 0, otherwise.
+ * low_usage = min( memory.current, memory.low )
  *
  *
  * Such definition of the effective memory.low provides the expected
-- 
1.8.3.1