On 2016/07/21 at 22:46, Juri Lelli wrote:
> On 21/07/16 15:36, Juri Lelli wrote:
>> On 21/07/16 15:21, Juri Lelli wrote:
>>> Hi,
>>>
>>> On 18/07/16 21:37, Xunlei Pang wrote:
>>>> On 2016/07/18 at 21:04, Juri Lelli wrote:
>>>>> On 15/07/16 18:39, Xunlei Pang wrote:
>>>>>> On 2016/07/13 at 18:58, Juri Lelli wrote:
>>>>> [...]
>>>>>
>>>>>> Since this is only called for queued cases now, there is no need to
>>>>>> check boosted stuff here. As enqueue_task(ENQUEUE_REPLENISH)
>>>>>> is called before check_class_changed() in rt_mutex_setprio().
>>>>>>
>>>>> But we don't do the same in setscheduler, right?
>>>> If p is deadline PI-boosted, setscheduler() won't call change its
>>>> sched_class.
>>>> If p isn't deadline PI-boosted, then pi_task is NULL.
>>>>
>>>> So, I think the added code won't hit. Did I miss something?
>>>>
>>> No, I think you are right.
>>>
>> Oh, and we need to filter the call after rt_mutex_setprio has
>> already issued a replenishment.
>>
> Does something like this on top of v4 make sense?
>
> ---
> kernel/sched/deadline.c | 22 +++++++---------------
> 1 file changed, 7 insertions(+), 15 deletions(-)
>
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index dc56f5be0112..6f05ac78711c 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -350,9 +350,8 @@ static inline void setup_new_dl_entity(struct
> sched_dl_entity *dl_se)
> {
> struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
> struct rq *rq = rq_of_dl_rq(dl_rq);
> - struct task_struct *pi_task;
> - struct sched_dl_entity *pi_se = dl_se;
>
> + WARN_ON(dl_se->dl_boosted);
> WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
>
> /*
> @@ -364,21 +363,12 @@ static inline void setup_new_dl_entity(struct
> sched_dl_entity *dl_se)
> return;
>
> /*
> - * Use the scheduling parameters of the top pi-waiter task,
> - * if we have one from which we can inherit a deadline.
> - */
> - if (dl_se->dl_boosted &&
> - (pi_task = rt_mutex_get_top_task(dl_task_of(dl_se))) &&
> - dl_prio(pi_task->normal_prio))
> - pi_se = &pi_task->dl;
> -
> - /*
> * We use the regular wall clock time to set deadlines in the
> * future; in fact, we must consider execution overheads (time
> * spent on hardirq context, etc.).
> */
> - dl_se->deadline = rq_clock(rq) + pi_se->dl_deadline;
> - dl_se->runtime = pi_se->dl_runtime;
> + dl_se->deadline = rq_clock(rq) + dl_se->dl_deadline;
> + dl_se->runtime = dl_se->dl_runtime;
> }
>
> /*
> @@ -1734,9 +1724,11 @@ static void switched_to_dl(struct rq *rq, struct
> task_struct *p)
> if (task_on_rq_queued(p)) {
> /*
> * If p is not queued we will update its parameters at next
> - * wakeup.
> + * wakeup. If p is dl_boosted we already updated its params in
> + * rt_mutex_setprio()->enqueue_task(..., ENQUEUE_REPLENISH).
> */
> - if (dl_time_before(p->dl.deadline, rq_clock(rq)))
> + if (dl_time_before(p->dl.deadline, rq_clock(rq)) &&
> + !p->dl.dl_boosted)
Hi Juri,
It looks good to me, only one question:
For on_rq boosted to deadline, p->dl.deadline has been updated after
rq_lock(rq) by
rt_mutex_setprio()->enqueue_task(..., ENQUEUE_REPLENISH) and no rq clock update
afterwards, so dl_time_before() will be false, seems p->dl.dl_boosted check is
needless.
Regards,
Xunlei
> setup_new_dl_entity(&p->dl);
>
> if (rq->curr != p) {
