Re: [PATCH 2/2] sched/deadline.c: pick and check task if double_lock_balance() unlock the rq

[Steven Rostedt]

On Thu, 12 Apr 2018 18:58:55 +0800
Li Bin <huawei.li...@huawei.com> wrote:

> @@ -1965,11 +1985,9 @@ static struct rq *find_lock_later_rq(struct 
> task_struct *task, struct rq *rq)
>  
>               /* Retry if something changed. */
>               if (double_lock_balance(rq, later_rq)) {
> -                     if (unlikely(task_rq(task) != rq ||
> -                                  !cpumask_test_cpu(later_rq->cpu, 
> &task->cpus_allowed) ||
> -                                  task_running(rq, task) ||
> -                                  !dl_task(task) ||
> -                                  !task_on_rq_queued(task))) {
> +                     struct task_struct *next_task = 
> pick_next_pushable_dl_task(rq);

I would do the same thing here, and add the comment from rt.c as it
is the same reason.

-- Steve

> +                     if (unlikely(next_task != task ||
> +                                             
> !cpumask_test_cpu(later_rq->cpu, &task->cpus_allowed))) {
>                               double_unlock_balance(rq, later_rq);
>                               later_rq = NULL;