Re: [PATCH v14 05/12] cpuset: Add an error state to cpuset.sched.partition

[Peter Zijlstra]

On Mon, Oct 15, 2018 at 04:29:30PM -0400, Waiman Long wrote:
> Handling error returned by update_parent_subparts_cpumask() in
> update_cpumasks_hier() is problematic as the states may become
> inconsistent. To avoid that and increase flexibility in handling other
> error cases, a new error state (-1) is added to the partition_root_state
> flag. This new error state is set internally and user cannot write this
> value to "cpuset.sched.partition".
> 
> In this error state, the partition root becomes an erroneous one. It is
> no longer a real partition root, but the CS_CPU_EXCLUSIVE flag will
> still be set as it can be changed back to a real one if appropriate
> change happens later on.

I feel this Changelog should be much more explicit about the reasons
this -1 state can happen. As is, I've got no clue.