On Thu, Nov 06, 2014 at 10:40:49AM +0800, Wanpeng Li wrote:
> @@ -538,6 +539,46 @@ again:
> update_rq_clock(rq);
> dl_se->dl_throttled = 0;
> dl_se->dl_yielded = 0;
> +
> + /*
> + * So if we find that the rq the task was on is no longer
> + * available, we need to select a new rq.
> + */
> + if (!rq->online) {
> + struct rq *later_rq = NULL;
> +
> + raw_spin_unlock(&rq->lock);
> +
> + later_rq = find_lock_later_rq(p, rq);
> +
> + if (!later_rq) {
> + int cpu;
> +
> + /*
> + * If cannot preempt any rq, fallback to pick any
> + * online cpu.
> + */
> + for_each_cpu(cpu, &p->cpus_allowed)
> + if (cpu_online(cpu))
> + later_rq = cpu_rq(cpu);
cpu = cpumask_any_and(cpu_active_mask,
tsk_cpus_allowed(p));
if (cpu >= nr_cpu_ids)
/* fail */
later_rq = cpu_rq(cpu);
> + if (!later_rq) {
> + pr_warn("fail to find any online and task
> + will never come back to us\n");
> + goto out;
> + }
> + }
> +
> + deactivate_task(rq, p, 0);
> + set_task_cpu(p, later_rq->cpu);
> + activate_task(later_rq, p, 0);
> +
> + resched_curr(later_rq);
> +
> + double_unlock_balance(rq, later_rq);
> +
> + goto out;
> + }
> +
> if (task_on_rq_queued(p)) {
> enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
> if (dl_task(rq->curr))
> @@ -555,7 +596,7 @@ again:
> }
> unlock:
> raw_spin_unlock(&rq->lock);
> -
> +out:
> return HRTIMER_NORESTART;
> }
>
> @@ -1185,8 +1226,12 @@ static int find_later_rq(struct task_struct *task)
> * We have to consider system topology and task affinity
> * first, then we can look for a suitable cpu.
> */
> - cpumask_copy(later_mask, task_rq(task)->rd->span);
> - cpumask_and(later_mask, later_mask, cpu_active_mask);
> + if (likely(task_rq(task)->online)) {
> + cpumask_copy(later_mask, task_rq(task)->rd->span);
> + cpumask_and(later_mask, later_mask, cpu_active_mask);
> + } else
> + /* for offline cpus we have a singleton rd */
> + cpumask_copy(later_mask, cpu_active_mask);
> cpumask_and(later_mask, later_mask, &task->cpus_allowed);
> best_cpu = cpudl_find(&task_rq(task)->rd->cpudl,
> task, later_mask);
cpumask_copy(later_mask, cpu_active_mask);
if (likely(task_rq(task)->online))
cpumask_and(later_mask, later_mask, task_rq(task)->rd->span);
Is the same, right and less lines.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
