3 files changed, 15 insertions, 9 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 4b78661c68d0..d8dd6560621b 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -180,7 +180,8 @@ static inline void mem_cgroup_dec_page_stat(struct page *page,
         mem_cgroup_update_page_stat(page, idx, -1);
 }
 
-bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg);
+bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
+                struct mem_cgroup *root);
 
 void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
 static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
@@ -357,7 +358,8 @@ static inline void mem_cgroup_dec_page_stat(struct page *page,
 }
 
 static inline
-bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg)
+bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
+                struct mem_cgroup *root)
 {
         return false;
 }
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 87a448dd9c10..c016e001c5b2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1773,11 +1773,13 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
 #endif
 
 /*
- * A group is eligible for the soft limit reclaim if it is
- *      a) is over its soft limit
+ * A group is eligible for the soft limit reclaim under the given root
+ * hierarchy if
+ *      a) it is over its soft limit
  *      b) any parent up the hierarchy is over its soft limit
  */
-bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg)
+bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg,
+                struct mem_cgroup *root)
 {
         struct mem_cgroup *parent = memcg;
 
@@ -1785,12 +1787,14 @@ bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg)
                 return true;
 
         /*
-         * If any parent up the hierarchy is over its soft limit then we
-         * have to obey and reclaim from this group as well.
+         * If any parent up to the root in the hierarchy is over its soft limit
+         * then we have to obey and reclaim from this group as well.
          */
         while((parent = parent_mem_cgroup(parent))) {
                 if (res_counter_soft_limit_excess(&parent->res))
                         return true;
+                if (parent == root)
+                        break;
         }
 
         return false;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index cf4643807ec2..1896e7ca494b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -142,7 +142,7 @@ static bool global_reclaim(struct scan_control *sc)
 
 static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc)
 {
-        return !mem_cgroup_disabled() && global_reclaim(sc);
+        return !mem_cgroup_disabled();
 }
 #else
 static bool global_reclaim(struct scan_control *sc)
@@ -2161,7 +2161,7 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim)
                         struct lruvec *lruvec;
 
                         if (soft_reclaim &&
-                            !mem_cgroup_soft_reclaim_eligible(memcg)) {
+                            !mem_cgroup_soft_reclaim_eligible(memcg, root)) {
                                 memcg = mem_cgroup_iter(root, memcg, &reclaim);
                                 continue;
                         }