[PATCH v2] memcg: oom: fix totalpages calculation formemory.swappiness==0

[Michal Hocko]

As Kosaki correctly pointed out, the glogal reclaim doesn't have this
issue because we _do_ swap on swappinnes==0 so the swap space has
to be considered. So the v2 is just acks + changelog fix.

Changes since v1
- drop a note about global swappiness affected as well from the
  changelog
- stable needs 3.2+ rather than 3.5+ because the fe35004f has been
  backported to stable
---