1 files changed, 21 insertions, 10 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index e1644a24009c..d3c8203cab6c 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -615,28 +615,32 @@ static inline void mem_cgroup_protection(struct mem_cgroup *root,
 void mem_cgroup_calculate_protection(struct mem_cgroup *root,
 				     struct mem_cgroup *memcg);
 
-static inline bool mem_cgroup_supports_protection(struct mem_cgroup *memcg)
+static inline bool mem_cgroup_unprotected(struct mem_cgroup *target,
+					  struct mem_cgroup *memcg)
 {
 	/*
 	 * The root memcg doesn't account charges, and doesn't support
-	 * protection.
+	 * protection. The target memcg's protection is ignored, see
+	 * mem_cgroup_calculate_protection() and mem_cgroup_protection()
 	 */
-	return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg);
-
+	return mem_cgroup_disabled() || mem_cgroup_is_root(memcg) ||
+		memcg == target;
 }
 
-static inline bool mem_cgroup_below_low(struct mem_cgroup *memcg)
+static inline bool mem_cgroup_below_low(struct mem_cgroup *target,
+					struct mem_cgroup *memcg)
 {
-	if (!mem_cgroup_supports_protection(memcg))
+	if (mem_cgroup_unprotected(target, memcg))
 		return false;
 
 	return READ_ONCE(memcg->memory.elow) >=
 		page_counter_read(&memcg->memory);
 }
 
-static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
+static inline bool mem_cgroup_below_min(struct mem_cgroup *target,
+					struct mem_cgroup *memcg)
 {
-	if (!mem_cgroup_supports_protection(memcg))
+	if (mem_cgroup_unprotected(target, memcg))
 		return false;
 
 	return READ_ONCE(memcg->memory.emin) >=
@@ -1209,12 +1213,19 @@ static inline void mem_cgroup_calculate_protection(struct mem_cgroup *root,
 {
 }
 
-static inline bool mem_cgroup_below_low(struct mem_cgroup *memcg)
+static inline bool mem_cgroup_unprotected(struct mem_cgroup *target,
+					  struct mem_cgroup *memcg)
+{
+	return true;
+}
+static inline bool mem_cgroup_below_low(struct mem_cgroup *target,
+					struct mem_cgroup *memcg)
 {
 	return false;
 }
 
-static inline bool mem_cgroup_below_min(struct mem_cgroup *memcg)
+static inline bool mem_cgroup_below_min(struct mem_cgroup *target,
+					struct mem_cgroup *memcg)
 {
 	return false;
 }