On Nov 22, 2018, at 3:34 PM, Michal Hocko <mhocko@kernel.org> wrote:

On Thu 22-11-18 10:56:04, 段熊春 wrote:

After long time dig, we find their lots of offline but not release memcg object in memory eating lots of memory.
Why this memcg not release? Because the inode pagecache use  some page which is charged to those memcg,

As already explained these objects should be reclaimed under memory
pressure. If they are not then there is a bug. And Roman has fixed some
of those recently.

Which kernel version are you using?
--
Michal Hocko
SUSE Labs