Re: [PATCH 14/34] mm, memcg: move memcg limit enforcement from zones to nodes

From: Johannes Weiner
Date: Tue Jul 12 2016 - 10:38:54 EST


On Fri, Jul 08, 2016 at 10:34:50AM +0100, Mel Gorman wrote:
> Memcg needs adjustment after moving LRUs to the node. Limits are tracked
> per memcg but the soft-limit excess is tracked per zone. As global page
> reclaim is based on the node, it is easy to imagine a situation where
> a zone soft limit is exceeded even though the memcg limit is fine.
>
> This patch moves the soft limit tree the node. Technically, all the variable
> names should also change but people are already familiar by the meaning of
> "mz" even if "mn" would be a more appropriate name now.
>
> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>

Yep, the soft limit tracking scope needs to match the reclaim scope.

Nice patch :)

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>