| Date | Fri, 31 Aug 2018 17:31:59 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH 13/15] blkcg: change blkg reference counting to use percpu_ref |
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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
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