On Thu, Jan 3, 2019 at 8:57 AM Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> wrote:
The point was the lifetime of tmpfs anon pages are not tied to any
On 1/2/19 1:45 PM, Shakeel Butt wrote:
On Wed, Jan 2, 2019 at 12:06 PM Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> wrote:Yes, but they are charged to swap space as regular anon pages.
The typical usecase of force empty is to try to reclaim as much asAnon pages can come from tmpfs files as well.
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.
task. Even though there aren't any task attached to a memcg, the tmpfs
anon pages will remain charged. Other than that, the old anon pages of
a task which have migrated away might still be charged to the old
memcg (if move_charge_at_immigrate is not set).
Yes.Thanks for sharing your usecase. So, you uses this for test only?Even though anonymous pages getI understand that force_empty is typically used before rmdir'ing a
swapped out, but they still get charged to swap space. So, it sounds
pointless to do swap for force empty.
memcg but it might be used differently by some users. We use this
interface to test memory reclaim behavior (anon and file).