Re: [PATCH v8 5/6] cgroup/cpuset: Update description of cpuset.cpus.partition in cgroup-v2.rst

On Tue, Nov 30, 2021 at 10:56:34PM -0500, Waiman Long [off-list ref] wrote:

quoted

quoted

     A valid parent partition may distribute out all its CPUs to
     its child partitions as long as it is not the root cgroup and
     there is no task associated with it.

A valid parent partition which isn't root never has tasks in them to begin
with.

I believe there is some corner cases where it is possible to put task in an
intermediate partition. That is why I put down this statement.

Just mind the threads -- cpuset controller is threaded and having tasks
in inner cgroup nodes is a real scenario. I wouldn't consider it a
corner case.

[ Actually, the paragraph could IMO be simplified:

A valid parent partition may distribute out all its CPUs to
its child partitions as long as there is no task associated with it.

Assuming there's always at least one kernel thread in the root cgroup
that can't be migrated anyway.]


Michal