On Fri, Sep 08, 2017 at 07:35:37AM -0700, Tejun Heo wrote:

* It's a bit weird to associate a kthread with a css without being
  specific.  If what's needed is a generic association (this kthread
  is temporarily servicing this cgroup), it should be associated with
  the cgroup.  But, I think it'd be better to make it specific instead
  - ie. kthread_set_io_css().

kthread[_set]_blkcg_css() probably is a more consistent name.

Thanks.

-- 
tejun