On Wed, Jan 2, 2019 at 12:06 PM Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> wrote: > > The typical usecase of force empty is to try to reclaim as much as > possible memory before offlining a memcg. Since there should be no > attached tasks to offlining memcg, the tasks anonymous pages would have > already been freed or uncharged. Anon pages can come from tmpfs files as well. > Even though anonymous pages get > swapped out, but they still get charged to swap space. So, it sounds > pointless to do swap for force empty. > I understand that force_empty is typically used before rmdir'ing a memcg but it might be used differently by some users. We use this interface to test memory reclaim behavior (anon and file). Anyways, I am not against changing the behavior, we can adapt internally but there might be other users using this interface differently. thanks, Shakeel
