continue;
}
-#if !defined(CONFIG_SLUB) || !defined(CONFIG_SLUB_DEBUG_ON)
+#if !defined(CONFIG_SLUB)
/*
* For simplicity, we won't check this in the list of memcg
* caches. We have control over memcg naming, and if there
if (err)
goto out_unlock;
+ if (memcg) {
+ /*
+ * Since per-memcg caches are created asynchronously on first
+ * allocation (see memcg_kmem_get_cache()), several threads can
+ * try to create the same cache, but only one of them may
+ * succeed. Therefore if we get here and see the cache has
+ * already been created, we silently return NULL.
+ */
+ if (cache_from_memcg_idx(parent_cache, memcg_cache_id(memcg)))
+ goto out_unlock;
+ }
+
/*
* Some allocators will constraint the set of valid flags to a subset
* of all flags. We expect them to define CACHE_CREATE_MASK in this
put_online_cpus();
if (err) {
+ /*
+ * There is no point in flooding logs with warnings or
+ * especially crashing the system if we fail to create a cache
+ * for a memcg. In this case we will be accounting the memcg
+ * allocation to the root cgroup until we succeed to create its
+ * own cache, but it isn't that critical.
+ */
+ if (!memcg)
+ return NULL;
+
if (flags & SLAB_PANIC)
panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
name, err);
list_del(&s->list);
if (!__kmem_cache_shutdown(s)) {
+ memcg_unregister_cache(s);
mutex_unlock(&slab_mutex);
if (s->flags & SLAB_DESTROY_BY_RCU)
rcu_barrier();
- memcg_unregister_cache(s);
memcg_free_cache_params(s);
kfree(s->name);
kmem_cache_free(kmem_cache, s);