---
 mm/memcontrol.c  |  5 ++++-
 mm/slab.h        | 25 +++++++++++++++++++++++++
 mm/slab_common.c |  1 +
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0655639433ed..9b2413c2e9ea 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -494,7 +494,10 @@ ino_t page_cgroup_ino(struct page *page)
        unsigned long ino = 0;

        rcu_read_lock();
-       memcg = READ_ONCE(page->mem_cgroup);
+       if (PageHead(page) && PageSlab(page))
+               memcg = memcg_from_slab_page(page);
+       else
+               memcg = READ_ONCE(page->mem_cgroup);
        while (memcg && !(memcg->css.flags & CSS_ONLINE))
                memcg = parent_mem_cgroup(memcg);
        if (memcg)

diff --git a/mm/slab.h b/mm/slab.h
index 7ba50e526d82..50fa534c0fc0 100644
--- a/mm/slab.h
+++ b/mm/slab.h

@@ -256,6 +256,26 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
        return s->memcg_params.root_cache;
 }

+/*
+ * Expects a pointer to a slab page. Please note, that PageSlab() check
+ * isn't sufficient, as it returns true also for tail compound slab pages,
+ * which do not have slab_cache pointer set.
+ * So this function assumes that the page can pass PageHead() and PageSlab()
+ * checks.
+ */
+static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
+{
+       struct kmem_cache *s;
+
+       WARN_ON_ONCE(!rcu_read_lock_held());
+
+       s = READ_ONCE(page->slab_cache);
+       if (s && !is_root_cache(s))
+               return rcu_dereference(s->memcg_params.memcg);
+
+       return NULL;
+}
+
 /*
  * Charge the slab page belonging to the non-root kmem_cache.
  * Can be called for non-root kmem_caches only.

@@ -353,6 +373,11 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
        return s;
 }

+static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
+{
+       return NULL;
+}
+
 static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
                                    struct kmem_cache *s)
 {

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 354762394162..9d2a3d6245dc 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c

@@ -254,6 +254,7 @@ static void memcg_unlink_cache(struct kmem_cache *s)
                list_del(&s->memcg_params.kmem_caches_node);
                mem_cgroup_put(rcu_dereference_protected(s->memcg_params.memcg,
                        lockdep_is_held(&slab_mutex)));
+               rcu_assign_pointer(s->memcg_params.memcg, NULL);
        }
 }
 #else
--

2.20.1