Re: cgroups(7): documenting cgroups v2 thread mode

From: Tejun Heo
Date: Wed Jan 10 2018 - 17:29:23 EST


Hello,

On Wed, Jan 10, 2018 at 11:18:48PM +0100, Michael Kerrisk (man-pages) wrote:
> Ahh yes. Now I understand. I made the description of the containment
> rules for cgroup.threads more explicit in the text:
>
> As with writing to cgroup.procs, some containment rules apply when
> writing to the cgroup.threads file:
>
> * The writer must have write permission on the cgroup.threads
> file in the destination cgroup.
>
> * The writer must have write permission on the cgroup.procs file
> in the common ancestor of the source and destination cgroups.
> (In some cases, the common ancestor may be the source or destiâ
> nation cgroup itself.)
>
> * The source and destination cgroups must be in the same threaded
> subtree. (Outside a threaded subtree, an attempt to move a
> thread by writing its thread ID to the cgroup.threads in a difâ
> ferent domain cgroup fails with the error EOPNOTSUPP.)
>
> Okay? (I realize that the last bullet point is a rather different way of
> formulating your idea that "the only extra restriction is that the domain
> cgroup must be the same for the source and destination". But I think the
> reformulation is easier to understand, no?)

It looks great to me. Me explaining that way is mostly from internal
/ conceptual POV. Yours is definitely more approachable.

Thanks.

--
tejun