Messages in this thread | | | Date | Mon, 13 Sep 2021 08:05:55 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH 1/2] cgroup: Fix incorrect warning from cgroup_apply_control_disable() |
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Hello,
On Thu, Sep 09, 2021 at 10:42:55PM -0400, Waiman Long wrote: > diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c > index 881ce1470beb..e31bca9fcd46 100644 > --- a/kernel/cgroup/cgroup.c > +++ b/kernel/cgroup/cgroup.c > @@ -3140,7 +3140,16 @@ static void cgroup_apply_control_disable(struct cgroup *cgrp) > if (!css) > continue; > > - WARN_ON_ONCE(percpu_ref_is_dying(&css->refcnt)); > + /* > + * A kill_css() might have been called previously, but > + * the css may still linger for a while before being > + * removed. Skip it in this case. > + */ > + if (percpu_ref_is_dying(&css->refcnt)) { > + WARN_ON_ONCE(css->parent && > + cgroup_ss_mask(dsct) & (1 << ss->id)); > + continue; > + }
This warning did help me catch some gnarly bugs. Any chance we can keep it for normal cases and elide it just for remounting?
Thanks.
-- tejun
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