Hello, On Thu, Aug 30, 2018 at 09:53:54PM -0400, Dennis Zhou wrote: > @@ -217,6 +240,10 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, > blkg_get(blkg->parent); > } > > + ret = percpu_ref_init(&blkg->refcnt, __blkg_release, 0, GFP_KERNEL); So, while this would work in some configs, you can't depend on RCU grace period inside percpu_ref. blkg is now percpu-reference counted and rcu protected object - it has to explicitly go through a rcu grace period before release. Thanks. -- tejun
