Messages in this thread | | | Date | Thu, 18 Aug 2011 07:56:49 +0200 | From | Michal Hocko <> | Subject | Re: [patch] memcg: pin execution to current cpu while draining stock |
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On Wed 17-08-11 21:49:27, Johannes Weiner wrote: > Commit d1a05b6 'memcg: do not try to drain per-cpu caches without > pages' added a drain_local_stock() call to a preemptible section. > > The draining task looks up the cpu-local stock twice to set the > draining-flag, then to drain the stock and clear the flag again. If > the task is migrated to a different CPU in between, noone will clear > the flag on the first stock and it will be forever undrainable. Its > charge can not be recovered and the cgroup can not be deleted anymore. > > Properly pin the task to the executing CPU while draining stocks. > > Signed-off-by: Johannes Weiner <jweiner@redhat.com> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com > Cc: Michal Hocko <mhocko@suse.cz>
My fault, I didn't realize that drain_local_stock needs preemption disabled. Sorry about that and good work, Johannes.
Acked-by: Michal Hocko <mhocko@suse.cz> -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic
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