1 files changed, 12 insertions, 3 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index afdd73553b88..a15557776d7d 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -130,6 +130,7 @@ int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
 #ifdef CONFIG_MEMCG_KMEM
 
 LIST_HEAD(slab_root_caches);
+static DEFINE_SPINLOCK(memcg_kmem_wq_lock);
 
 void slab_init_memcg_params(struct kmem_cache *s)
 {
@@ -734,14 +735,22 @@ static void kmemcg_cache_deactivate(struct kmem_cache *s)
 
         __kmemcg_cache_deactivate(s);
 
+        /*
+         * memcg_kmem_wq_lock is used to synchronize memcg_params.dying
+         * flag and make sure that no new kmem_cache deactivation tasks
+         * are queued (see flush_memcg_workqueue() ).
+         */
+        spin_lock_irq(&memcg_kmem_wq_lock);
         if (s->memcg_params.root_cache->memcg_params.dying)
-                return;
+                goto unlock;
 
         /* pin memcg so that @s doesn't get destroyed in the middle */
         css_get(&s->memcg_params.memcg->css);
 
         s->memcg_params.work_fn = __kmemcg_cache_deactivate_after_rcu;
         call_rcu(&s->memcg_params.rcu_head, kmemcg_rcufn);
+unlock:
+        spin_unlock_irq(&memcg_kmem_wq_lock);
 }
 
 void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
@@ -851,9 +860,9 @@ static int shutdown_memcg_caches(struct kmem_cache *s)
 
 static void flush_memcg_workqueue(struct kmem_cache *s)
 {
-        mutex_lock(&slab_mutex);
+        spin_lock_irq(&memcg_kmem_wq_lock);
         s->memcg_params.dying = true;
-        mutex_unlock(&slab_mutex);
+        spin_unlock_irq(&memcg_kmem_wq_lock);
 
         /*
          * SLAB and SLUB deactivate the kmem_caches through call_rcu. Make