Re: [PATCH 3/5] cgroup/cpuset: Allow non-top parent partition root to distribute out all CPUs

Tejun Heo
2021-06-16T20:57:54Z

Hello,

On Thu, Jun 03, 2021 at 05:24:14PM -0400, Waiman Long wrote:
> @@ -2181,6 +2192,13 @@ static int cpuset_can_attach(struct cgroup_taskset *tset)
> (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
> goto out_unlock;
>
> + /*
> + * On default hierarchy, task cannot be moved to a cpuset with empty
> + * effective cpus.
> + */
> + if (is_in_v2_mode() && cpumask_empty(cs->effective_cpus))
> + goto out_unlock;
> +

This is inconsistent with how other events which leave a root partition
empty is handled. Woudln't it be more consistent to switch the parent to
PRS_ERROR and behave accordingly but allow it to have valid child roots?

Thanks.

--
tejun