On Fri, Nov 22, 2019 at 05:28:46PM +0100, Christian Borntraeger wrote:
> On 21.11.19 19:45, Roman Gushchin wrote:
> > I see. Do you know, which kmem_cache it is? If not, can you, please,
> > figure it out?
>
> The release function for that ref is kmemcg_cache_shutdown.
>
Hi Christian!
Can you, please, test if the following patch resolves the problem?
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 8afa188f6e20..628e5f0ee19e 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -888,6 +888,8 @@ static int shutdown_memcg_caches(struct kmem_cache *s)
static void flush_memcg_workqueue(struct kmem_cache *s)
{
+ bool wait_for_children;
+
spin_lock_irq(&memcg_kmem_wq_lock);
s->memcg_params.dying = true;
spin_unlock_irq(&memcg_kmem_wq_lock);
@@ -904,6 +906,13 @@ static void flush_memcg_workqueue(struct kmem_cache *s)
* previous workitems on workqueue are processed.
*/
flush_workqueue(memcg_kmem_cache_wq);
+
+ mutex_lock(&slab_mutex);
+ wait_for_children = !list_empty(&s->memcg_params.children);
+ mutex_unlock(&slab_mutex);
+
+ if (wait_for_children)
+ rcu_barrier();
}
#else
static inline int shutdown_memcg_caches(struct kmem_cache *s)
--
Thanks!
