4 files changed, 95 insertions, 1 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cc13797d0fb..270a3678985 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2779,6 +2779,19 @@ static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
                 (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK);
 }
 
+/*
+ * This is a bit cumbersome, but it is rarely used and avoids a backpointer
+ * in the memcg_cache_params struct.
+ */
+static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p)
+{
+        struct kmem_cache *cachep;
+
+        VM_BUG_ON(p->is_root_cache);
+        cachep = p->root_cache;
+        return cachep->memcg_params->memcg_caches[memcg_cache_id(p->memcg)];
+}
+
 static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
 {
         struct res_counter *fail_res;
@@ -3056,6 +3069,31 @@ static inline void memcg_resume_kmem_account(void)
         current->memcg_kmem_skip_account--;
 }
 
+static void kmem_cache_destroy_work_func(struct work_struct *w)
+{
+        struct kmem_cache *cachep;
+        struct memcg_cache_params *p;
+
+        p = container_of(w, struct memcg_cache_params, destroy);
+
+        cachep = memcg_params_to_cache(p);
+
+        if (!atomic_read(&cachep->memcg_params->nr_pages))
+                kmem_cache_destroy(cachep);
+}
+
+void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
+{
+        if (!cachep->memcg_params->dead)
+                return;
+
+        /*
+         * We have to defer the actual destroying to a workqueue, because
+         * we might currently be in a context that cannot sleep.
+         */
+        schedule_work(&cachep->memcg_params->destroy);
+}
+
 static char *memcg_cache_name(struct mem_cgroup *memcg, struct kmem_cache *s)
 {
         char *name;
@@ -3125,6 +3163,7 @@ static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
 
         mem_cgroup_get(memcg);
         new_cachep->memcg_params->root_cache = cachep;
+        atomic_set(&new_cachep->memcg_params->nr_pages , 0);
 
         cachep->memcg_params->memcg_caches[idx] = new_cachep;
         /*
@@ -3143,6 +3182,25 @@ struct create_work {
         struct work_struct work;
 };
 
+static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
+{
+        struct kmem_cache *cachep;
+        struct memcg_cache_params *params;
+
+        if (!memcg_kmem_is_active(memcg))
+                return;
+
+        mutex_lock(&memcg->slab_caches_mutex);
+        list_for_each_entry(params, &memcg->memcg_slab_caches, list) {
+                cachep = memcg_params_to_cache(params);
+                cachep->memcg_params->dead = true;
+                INIT_WORK(&cachep->memcg_params->destroy,
+                          kmem_cache_destroy_work_func);
+                schedule_work(&cachep->memcg_params->destroy);
+        }
+        mutex_unlock(&memcg->slab_caches_mutex);
+}
+
 static void memcg_create_cache_work_func(struct work_struct *w)
 {
         struct create_work *cw;
@@ -3358,6 +3416,10 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order)
         VM_BUG_ON(mem_cgroup_is_root(memcg));
         memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
 }
+#else
+static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
+{
+}
 #endif /* CONFIG_MEMCG_KMEM */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -5975,6 +6037,7 @@ static void mem_cgroup_css_offline(struct cgroup *cont)
         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
         mem_cgroup_reparent_charges(memcg);
+        mem_cgroup_destroy_all_caches(memcg);
 }
 
 static void mem_cgroup_css_free(struct cgroup *cont)
diff --git a/mm/slab.c b/mm/slab.c
index e265865e870..7467343f9fe 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1895,6 +1895,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
                 if (page->pfmemalloc)
                         SetPageSlabPfmemalloc(page + i);
         }
+        memcg_bind_pages(cachep, cachep->gfporder);
 
         if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
                 kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid);
@@ -1931,6 +1932,8 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr)
                 __ClearPageSlab(page);
                 page++;
         }
+
+        memcg_release_pages(cachep, cachep->gfporder);
         if (current->reclaim_state)
                 current->reclaim_state->reclaimed_slab += nr_freed;
         free_memcg_kmem_pages((unsigned long)addr, cachep->gfporder);
diff --git a/mm/slab.h b/mm/slab.h
index c95e922b166..43d8a38b534 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -117,6 +117,21 @@ static inline bool cache_match_memcg(struct kmem_cache *cachep,
                                 (cachep->memcg_params->memcg == memcg);
 }
 
+static inline void memcg_bind_pages(struct kmem_cache *s, int order)
+{
+        if (!is_root_cache(s))
+                atomic_add(1 << order, &s->memcg_params->nr_pages);
+}
+
+static inline void memcg_release_pages(struct kmem_cache *s, int order)
+{
+        if (is_root_cache(s))
+                return;
+
+        if (atomic_sub_and_test((1 << order), &s->memcg_params->nr_pages))
+                mem_cgroup_destroy_cache(s);
+}
+
 static inline bool slab_equal_or_root(struct kmem_cache *s,
                                         struct kmem_cache *p)
 {
@@ -135,6 +150,14 @@ static inline bool cache_match_memcg(struct kmem_cache *cachep,
         return true;
 }
 
+static inline void memcg_bind_pages(struct kmem_cache *s, int order)
+{
+}
+
+static inline void memcg_release_pages(struct kmem_cache *s, int order)
+{
+}
+
 static inline bool slab_equal_or_root(struct kmem_cache *s,
                                       struct kmem_cache *p)
 {
diff --git a/mm/slub.c b/mm/slub.c
index ef39e872b8e..692177bebdf 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1344,6 +1344,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
         void *start;
         void *last;
         void *p;
+        int order;
 
         BUG_ON(flags & GFP_SLAB_BUG_MASK);
 
@@ -1352,7 +1353,9 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
         if (!page)
                 goto out;
 
+        order = compound_order(page);
         inc_slabs_node(s, page_to_nid(page), page->objects);
+        memcg_bind_pages(s, order);
         page->slab_cache = s;
         __SetPageSlab(page);
         if (page->pfmemalloc)
@@ -1361,7 +1364,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
         start = page_address(page);
 
         if (unlikely(s->flags & SLAB_POISON))
-                memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
+                memset(start, POISON_INUSE, PAGE_SIZE << order);
 
         last = start;
         for_each_object(p, s, start, page->objects) {
@@ -1402,6 +1405,8 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
 
         __ClearPageSlabPfmemalloc(page);
         __ClearPageSlab(page);
+
+        memcg_release_pages(s, order);
         reset_page_mapcount(page);
         if (current->reclaim_state)
                 current->reclaim_state->reclaimed_slab += pages;