On Fri, Sep 28, 2012 at 03:34:19PM +0400, Glauber Costa wrote:
> On 09/27/2012 05:44 PM, Michal Hocko wrote:
> > Anyway, I have just noticed that __mem_cgroup_try_charge does
> > VM_BUG_ON(css_is_removed(&memcg->css)) on a given memcg so you should
> > keep css ref count up as well.
> 
> IIRC, css_get will prevent the cgroup directory from being removed.
> Because some allocations are expected to outlive the cgroup, we
> specifically don't want that.

That synchronous ref draining is going away.  Maybe we can do that
before kmemcg?  Michal, do you have some timeframe on mind?

Thanks.

-- 
tejun