On Thu 04-10-12 14:09:16, Johannes Weiner wrote: > page_referenced() counts only references of mm's that are associated > with the memcg hierarchy that is being reclaimed. However, if it > races with the owner of the mm exiting, mm->owner may be NULL. Don't > crash, just ignore the reference.
This seems to be fixed by Hugh's patch 3a981f48 "memcg: fix use_hierarchy css_is_ancestor oops regression" which seems to be merged already. > > Signed-off-by: Johannes Weiner <han...@cmpxchg.org> > Cc: sta...@kernel.org [3.5] > --- > include/linux/memcontrol.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 8d9489f..8686294 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -91,7 +91,7 @@ int mm_match_cgroup(const struct mm_struct *mm, const > struct mem_cgroup *cgroup) > > rcu_read_lock(); > memcg = mem_cgroup_from_task(rcu_dereference((mm)->owner)); > - match = __mem_cgroup_same_or_subtree(cgroup, memcg); > + match = memcg && __mem_cgroup_same_or_subtree(cgroup, memcg); > rcu_read_unlock(); > return match; > } > -- > 1.7.11.4 > -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
