Re: [PATCH v2 3/4] cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated

On Fri, Mar 17, 2023 at 02:05:32PM -0400, Waiman Long longman@redhat.com wrote:

A cpu will be in the subparts_cpus only if it has been given to the child partition. So when it becomes online, it will become part of the scheduling domain that child partition. Only the tasks in that child partition will get their cpumasks updated to use it, not those in the top cpuset.

Right, it's actually the difference between offlining a CPU and giving it to a sub-partition (hence a removed child (or switched to member) before CPU onlining). It's clear to me now.

Thanks, Michal