Re: [PATCH 1/2] cpuset: Fix cpuset_cpus_allowed() to not filter offline CPUs

[Peter Zijlstra]

On Fri, Feb 03, 2023 at 10:13:10AM -0500, Waiman Long wrote:

> I think I know where the problem is. It is due to the fact the cpuset
> hotplug code doesn't update cpumasks of the tasks in the top cpuset (root)
> at all when there is a cpu offline or online event. It is probably because
> for some of the tasks in the top cpuset, especially the percpu kthread,
> changing their cpumasks can be catastrophic. The hotplug code does update
> the cpumasks of the tasks that are not in the top cpuset. This problem is
> irrespective of whether v1 or v2 is in use.

I've been saying this exact thing for how many mails now?