Re: [PATCH v5] cgroup: Add new capability to allow a process to migrate other tasks between cgroups

From: Tejun Heo
Date: Tue Dec 13 2016 - 13:41:11 EST


On Tue, Dec 13, 2016 at 08:08:16AM -0800, John Stultz wrote:
> On Tue, Dec 13, 2016 at 1:47 AM, Michael Kerrisk (man-pages)
> <mtk.manpages@xxxxxxxxx> wrote:
> > On 13 December 2016 at 02:39, John Stultz <john.stultz@xxxxxxxxxx> wrote:
> > So, back to the discussion of silos. I understand the argument for
> > wanting a new silo. But, in that case can we at least try not to make
> > it a single-use silo?
> >
> > How about CAP_CGROUP_CONTROL or some such, with the idea that this
> > might be a capability that allows the holder to step outside usual
> > cgroup rules? At the moment, that capability would allow only one such
> > step, but maybe there would be others in the future.
> This sounds reasonable to me. Tejun/Andy: Objections?

Control group control? The word control has a specific meaning for
cgroups and that second control doesn't make much sense to me. Given
how this is mostly to patch up a hole in v1's delegation model and how
migration operations are different from others, I doubt that we will
end up overloading it. Maybe just CAP_CGROUP?