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Diffstat (limited to 'mm/slab_common.c')
-rw-r--r--mm/slab_common.c89
1 files changed, 55 insertions, 34 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 0b7bb399b0e4..1ec3c619ba04 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -171,13 +171,26 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size,
struct kmem_cache *parent_cache)
{
struct kmem_cache *s = NULL;
- int err = 0;
+ int err;
get_online_cpus();
mutex_lock(&slab_mutex);
- if (!kmem_cache_sanity_check(memcg, name, size) == 0)
- goto out_locked;
+ err = kmem_cache_sanity_check(memcg, name, size);
+ 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
@@ -189,44 +202,47 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size,
s = __kmem_cache_alias(memcg, name, size, align, flags, ctor);
if (s)
- goto out_locked;
+ goto out_unlock;
+ err = -ENOMEM;
s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
- if (s) {
- s->object_size = s->size = size;
- s->align = calculate_alignment(flags, align, size);
- s->ctor = ctor;
+ if (!s)
+ goto out_unlock;
- if (memcg_register_cache(memcg, s, parent_cache)) {
- kmem_cache_free(kmem_cache, s);
- err = -ENOMEM;
- goto out_locked;
- }
+ s->object_size = s->size = size;
+ s->align = calculate_alignment(flags, align, size);
+ s->ctor = ctor;
- s->name = kstrdup(name, GFP_KERNEL);
- if (!s->name) {
- kmem_cache_free(kmem_cache, s);
- err = -ENOMEM;
- goto out_locked;
- }
+ s->name = kstrdup(name, GFP_KERNEL);
+ if (!s->name)
+ goto out_free_cache;
- err = __kmem_cache_create(s, flags);
- if (!err) {
- s->refcount = 1;
- list_add(&s->list, &slab_caches);
- memcg_cache_list_add(memcg, s);
- } else {
- kfree(s->name);
- kmem_cache_free(kmem_cache, s);
- }
- } else
- err = -ENOMEM;
+ err = memcg_alloc_cache_params(memcg, s, parent_cache);
+ if (err)
+ goto out_free_cache;
+
+ err = __kmem_cache_create(s, flags);
+ if (err)
+ goto out_free_cache;
+
+ s->refcount = 1;
+ list_add(&s->list, &slab_caches);
+ memcg_register_cache(s);
-out_locked:
+out_unlock:
mutex_unlock(&slab_mutex);
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",
@@ -236,11 +252,15 @@ out_locked:
name, err);
dump_stack();
}
-
return NULL;
}
-
return s;
+
+out_free_cache:
+ memcg_free_cache_params(s);
+ kfree(s->name);
+ kmem_cache_free(kmem_cache, s);
+ goto out_unlock;
}
struct kmem_cache *
@@ -263,11 +283,12 @@ void kmem_cache_destroy(struct kmem_cache *s)
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_release_cache(s);
+ memcg_free_cache_params(s);
kfree(s->name);
kmem_cache_free(kmem_cache, s);
} else {