Re: [PATCH] cgroup: Fix potential race between cgroup_exit and cpuset_attach

[Tejun Heo]

Hello,

On Wed, Aug 30, 2017 at 06:23:50PM +0530, Neeraj Upadhyay wrote:
> cpuset_hotplug_workfn()
>   cgroup_transfer_tasks()
>     cgroup_migrate()
>       cgroup_migrate_execute()
>           <TASK EXIT>
>           list_del_init(&task->cg_list)
>         cpuset_attach()
>           cgroup_taskset_first(tset, &css) // css is not set
>           guarantee_online_mems(cs, ...) // data abort

I don't think this can happen anymore.  We lock out task exits during
migration and don't call migration callbacks if there's no tasks to
migrate.

Thanks.

-- 
tejun