[$] A milestone for control groups

By corbet Changes to core-kernel subsystems take time but, even so, one can only
imagine that Tejun Heo never expected the process of fixing the
control-group interface to take more than five years. Disagreements over
the design of the new control-group interface have delayed its adoption;
even though most of the code has been in the kernel for some time, not all
controllers work with it. It would now appear, however, that agreement has
been reached on an important final piece, which is currently on track to be
merged for the 4.14 development cycle.

From: LWN