Re: [PATCH] sched/deadline: Replace rq_of_dl_rq(dl_rq_of_se(dl_se)) with ... ...task_rq(dl_task_of(dl_se))

[Qi Zheng]

On 2020/10/13 下午11:48, Peter Zijlstra wrote:
> On Tue, Oct 13, 2020 at 10:31:40PM +0800, Qi Zheng wrote:
>> The rq is already obtained in the dl_rq_of_se() function:
>> struct task_struct *p = dl_task_of(dl_se);
>> struct rq *rq = task_rq(p);
>> So there is no need to do extra conversion.
>>
>> Signed-off-by: Qi Zheng <arch0.zheng@xxxxxxxxx>
>> ---
>> kernel/sched/deadline.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
>> index 6d93f4518734..f64e577f6aba 100644
>> --- a/kernel/sched/deadline.c
>> +++ b/kernel/sched/deadline.c
>> @@ -1152,7 +1152,7 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se)
>> static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se)
>> {
>> struct task_struct *p = dl_task_of(dl_se);
>> - struct rq *rq = rq_of_dl_rq(dl_rq_of_se(dl_se));
>> + struct rq *rq = task_rq(p);
>>
>> if (dl_time_before(dl_se->deadline, rq_clock(rq)) &&
>> dl_time_before(rq_clock(rq), dl_next_period(dl_se))) {
>> @@ -1498,7 +1498,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se,
>> replenish_dl_entity(dl_se, pi_se);
>> } else if ((flags & ENQUEUE_RESTORE) &&
>> dl_time_before(dl_se->deadline,
>> - rq_clock(rq_of_dl_rq(dl_rq_of_se(dl_se))))) {
>> + rq_clock(task_rq(dl_task_of(dl_se))))) {
>> setup_new_dl_entity(dl_se);
>> }
>
> Consider where we're going:
>
> https://lkml.kernel.org/r/20200807095051.385985-1-juri.lelli@xxxxxxxxxx
>
> then a dl_entity is no longer immediately a task and the above is no
> longer true.
>

Thanks for your reply, I saw in the patch below that the dl_rq_of_se()
has been changed to the rq_of_dl_se(), so the above is no longer needed.

    [RFC PATCH v2 4/6] sched/deadline: Introduce deadline servers

In addition, when will the SCHED_DEADLINE server infrastructure is
expected to be integrated into the mainline? It looks great!

Peter Zijlstra <peterz@xxxxxxxxxxxxx> 于2020年10月13日周二 下午11:48写道：
>
> On Tue, Oct 13, 2020 at 10:31:40PM +0800, Qi Zheng wrote:
> > The rq is already obtained in the dl_rq_of_se() function:
> >       struct task_struct *p = dl_task_of(dl_se);
> >         struct rq *rq = task_rq(p);
> > So there is no need to do extra conversion.
> >
> > Signed-off-by: Qi Zheng <arch0.zheng@xxxxxxxxx>
> > ---
> >  kernel/sched/deadline.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> > index 6d93f4518734..f64e577f6aba 100644
> > --- a/kernel/sched/deadline.c
> > +++ b/kernel/sched/deadline.c
> > @@ -1152,7 +1152,7 @@ void init_dl_task_timer(struct sched_dl_entity *dl_se)
> >  static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se)
> >  {
> >       struct task_struct *p = dl_task_of(dl_se);
> > -     struct rq *rq = rq_of_dl_rq(dl_rq_of_se(dl_se));
> > +     struct rq *rq = task_rq(p);
> >
> >       if (dl_time_before(dl_se->deadline, rq_clock(rq)) &&
> >           dl_time_before(rq_clock(rq), dl_next_period(dl_se))) {
> > @@ -1498,7 +1498,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se,
> >               replenish_dl_entity(dl_se, pi_se);
> >       } else if ((flags & ENQUEUE_RESTORE) &&
> >                 dl_time_before(dl_se->deadline,
> > -                              rq_clock(rq_of_dl_rq(dl_rq_of_se(dl_se))))) {
> > +                              rq_clock(task_rq(dl_task_of(dl_se))))) {
> >               setup_new_dl_entity(dl_se);
> >       }
>
> Consider where we're going:
>
>   https://lkml.kernel.org/r/20200807095051.385985-1-juri.lelli@xxxxxxxxxx
>
> then a dl_entity is no longer immediately a task and the above is no
> longer true.