From 0a6b76dd23fa08c5fd7b68acdb55018a37afd4aa Mon Sep 17 00:00:00 2001
From: Vladimir Davydov <vdavydov@virtuozzo.com>
Date: Thu, 17 Mar 2016 14:18:42 -0700
Subject: mm: workingset: make shadow node shrinker memcg aware

Workingset code was recently made memcg aware, but shadow node shrinker
is still global.  As a result, one small cgroup can consume all memory
available for shadow nodes, possibly hurting other cgroups by reclaiming
their shadow nodes, even though reclaim distances stored in its shadow
nodes have no effect.  To avoid this, we need to make shadow node
shrinker memcg aware.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index bc8e4e2..1191d79 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -403,6 +403,9 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 		int nr_pages);
 
+unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+					   int nid, unsigned int lru_mask);
+
 static inline
 unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
 {
@@ -661,6 +664,13 @@ mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 {
 }
 
+static inline unsigned long
+mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+			     int nid, unsigned int lru_mask)
+{
+	return 0;
+}
+
 static inline void
 mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 341bf86..ae8b81c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -638,9 +638,8 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
 	__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
 }
 
-static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
-						  int nid,
-						  unsigned int lru_mask)
+unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
+					   int nid, unsigned int lru_mask)
 {
 	unsigned long nr = 0;
 	int zid;
diff --git a/mm/workingset.c b/mm/workingset.c
index 68e8cd9..8a75f8d 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -349,8 +349,12 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
 	shadow_nodes = list_lru_shrink_count(&workingset_shadow_nodes, sc);
 	local_irq_enable();
 
-	pages = node_page_state(sc->nid, NR_ACTIVE_FILE) +
-		node_page_state(sc->nid, NR_INACTIVE_FILE);
+	if (memcg_kmem_enabled())
+		pages = mem_cgroup_node_nr_lru_pages(sc->memcg, sc->nid,
+						     LRU_ALL_FILE);
+	else
+		pages = node_page_state(sc->nid, NR_ACTIVE_FILE) +
+			node_page_state(sc->nid, NR_INACTIVE_FILE);
 
 	/*
 	 * Active cache pages are limited to 50% of memory, and shadow
@@ -460,7 +464,7 @@ static struct shrinker workingset_shadow_shrinker = {
 	.count_objects = count_shadow_nodes,
 	.scan_objects = scan_shadow_nodes,
 	.seeks = DEFAULT_SEEKS,
-	.flags = SHRINKER_NUMA_AWARE,
+	.flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE,
 };
 
 /*
-- 
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