Re: [PATCH] cgroup/cpuset: Creating or adding CPUs to partition not allowed without privilege

[Waiman Long]

On 4/28/26 11:44 AM, Tejun Heo wrote:
> Hello,
>
> On Tue, Apr 28, 2026 at 11:19:16AM -0400, Waiman Long wrote:
> ...
> > Thank for the comment. Yes, that can be a valid configuration.
> >
> > One possible workaround may be to see if the current user has write access
> > to its parent partition root. If so, we can allow it to create a
> > sub-partition, if not, we will forbid it.
> I think this whole thing is a confusion. First of all, resource knobs in any
> given cgroup is owned by the parent. Delegations where the perm to a
> resource knob is given to delegatee is not supported and expected to affect
> resource distribution w.r.t. its siblings. Partition isn't special in this
> regard. memory.low or min can create similar effects. Maybe I'm missing
> something but I don't see anything happening that's not supposed to happen.

You are right. I am a bit confused about the exact delegation rules. 
After reading the delegation section of the cgroup-v2.rst file, I 
realize that the current behavior should be OK. For clarity, I am 
planning to send a documentation patch to clarify the current partition 
delegation behavior.

Thanks,
Longman