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.
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
--
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/
