Re: [PATCH] KVM: Move VM's worker kthreads back to the original cgroups before exiting.

[Vipin Sharma]

On Wed, Dec 15, 2021 at 10:27 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> So the issue is that the kthread_stop happens around the time
> exit_task_work() destroys the VM, but the process can go on and signal
> its demise to the parent process before the kthread has been completely
> dropped.  Not even close() can fix it, though it may reduce the window
> completely, so I agree that this is a bug and vhost has the same bug too.
>
> Due to the issue with kthreadd_task not being exported, perhaps you can
> change cgroup_attach_task_all to use kthreadd_task if the "from"
> argument is NULL?

Thanks for the suggestion. This also works, I will send out a patch.