On Wed, Feb 03, 2016 at 10:52:13AM +0300, Dmitry Safonov wrote:
...
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index b50aef0..2bfc0b1 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -451,6 +451,8 @@ EXPORT_SYMBOL(kmem_cache_create);
> static int shutdown_cache(struct kmem_cache *s,
> struct list_head *release, bool *need_rcu_barrier)
> {
> + sysfs_slab_remove(s);
> +
shutdown_cache is called with slab_mutex held. slab_attr_store may take
the mutex. So placing sysfs_slab_remove here introduces a potential
deadlock.
> if (__kmem_cache_shutdown(s) != 0)
> return -EBUSY;
>
> @@ -468,13 +470,8 @@ static void release_caches(struct list_head *release,
> bool need_rcu_barrier)
> if (need_rcu_barrier)
> rcu_barrier();
>
> - list_for_each_entry_safe(s, s2, release, list) {
> -#ifdef SLAB_SUPPORTS_SYSFS
> - sysfs_slab_remove(s);
> -#else
> + list_for_each_entry_safe(s, s2, release, list)
> slab_kmem_cache_release(s);
> -#endif
> - }
> }
>
> #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
> @@ -614,6 +611,7 @@ void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
> list_for_each_entry_safe(s, s2, &slab_caches, list) {
> if (is_root_cache(s) || s->memcg_params.memcg != memcg)
> continue;
> +
Please remove this hunk.
> /*
> * The cgroup is about to be freed and therefore has no charges
> * left. Hence, all its caches must be empty by now.
> diff --git a/mm/slub.c b/mm/slub.c
> index 2e1355a..b6a68b7 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -5296,11 +5296,6 @@ static void memcg_propagate_slab_attrs(struct
> kmem_cache *s)
> #endif
> }
>
> -static void kmem_cache_release(struct kobject *k)
> -{
> - slab_kmem_cache_release(to_slab(k));
> -}
> -
> static const struct sysfs_ops slab_sysfs_ops = {
> .show = slab_attr_show,
> .store = slab_attr_store,
> @@ -5308,7 +5303,6 @@ static const struct sysfs_ops slab_sysfs_ops = {
>
> static struct kobj_type slab_ktype = {
> .sysfs_ops = &slab_sysfs_ops,
> - .release = kmem_cache_release,
I surmise this will resurrect the bug that was fixed by 41a212859a4dd
("slub: use sysfs'es release mechanism for kmem_cache").
Thanks,
Vladimir
