lkml.org 
[lkml]   [2014]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v3] sched/deadline: support dl task migration during cpu hotplug
Hi Peter,
On 14/11/11 下午7:33, Peter Zijlstra wrote:
> 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);

Ok.

>> + 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.

Thanks for your great help! I will fold these to my patch and send out a
newer version tomorrow. ;-)

Regards,
Wanpeng Li

>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2014-11-11 13:21    [W:1.262 / U:0.568 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site