Messages in this thread | | | Date | Fri, 19 Oct 2012 13:17:36 -0700 | From | Tejun Heo <> | Subject | Re: [PATCH 4/6] cgroups: forbid pre_destroy callback to fail |
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On Fri, Oct 19, 2012 at 05:33:18PM +0800, Li Zefan wrote: > On 2012/10/17 21:30, Michal Hocko wrote: > > Now that mem_cgroup_pre_destroy callback doesn't fail finally we can > > safely move on and forbit all the callbacks to fail. The last missing > > piece is moving cgroup_call_pre_destroy after cgroup_clear_css_refs so > > that css_tryget fails so no new charges for the memcg can happen. > > > The callbacks are also called from within cgroup_lock to guarantee that > > no new tasks show up. > > I'm afraid this won't work. See commit 3fa59dfbc3b223f02c26593be69ce6fc9a940405 > ("cgroup: fix potential deadlock in pre_destroy")
Yeah, you're right. Argh... we really should unexport cgroup_lock soon.
Thanks.
-- tejun
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