Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On Fri, Jul 20, 2018 at 05:36:06PM +0200, Daniel Bristot de Oliveira wrote: > Am I missing something? Nothing, I was missing why exactly this was deadline only. Figured it out now :-)
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On Fri, Jul 20, 2018 at 05:36:06PM +0200, Daniel Bristot de Oliveira wrote: > Am I missing something? Nothing, I was missing why exactly this was deadline only. Figured it out now :-)
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On 20/07/18 17:36, Daniel Bristot de Oliveira wrote:
> On 07/20/2018 02:53 PM, Juri Lelli wrote:
> > On 20/07/18 14:48, Peter Zijlstra wrote:
> >> On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote:
> >>> On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira
> >>> wrote:
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index fbfc3f1d368a..8b50eea4b607 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq)
> sub_rq_bw(_task->dl, >dl);
> set_task_cpu(next_task, later_rq->cpu);
> add_rq_bw(_task->dl, _rq->dl);
> +
> +/*
> + * Update the later_rq clock here, because the clock is used
> + * by the cpufreq_update_util() inside __add_running_bw().
> + */
> +update_rq_clock(later_rq);
> add_running_bw(_task->dl, _rq->dl);
> -activate_task(later_rq, next_task, 0);
> +activate_task(later_rq, next_task, ENQUEUE_NOCLOCK);
> ret = 1;
>
> resched_curr(later_rq);
> >>>
> >>> Why isn't push_rt_task() affected by the very same issue?
> >>
> >> Aah, I see, its the add_running_bw() think; for which RT doesn't have a
> >> counter-part.
> >
> > Right, but doesn't enqueue_top_rt_rq end-up being called by activate_
> > task on lowest_rq? Mmm.
>
>
> AFAICS we have:
>
> push_rt_task() {
> activate_task() {
> enqueue_task(,,(flags=0)) {
> if (!(flags & ENQUEUE_NOCLOCK))
> update_rq_clock(rq);
> enqueue_task_rt() {
> enqueue_rt_entity() {
> enqueue_top_rt_rq();
> }
> }
> }
> }
>
> So we will have the clock updated already...
>
> Am I missing something?
Ah, indeed.
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On 20/07/18 17:36, Daniel Bristot de Oliveira wrote:
> On 07/20/2018 02:53 PM, Juri Lelli wrote:
> > On 20/07/18 14:48, Peter Zijlstra wrote:
> >> On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote:
> >>> On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira
> >>> wrote:
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index fbfc3f1d368a..8b50eea4b607 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq)
> sub_rq_bw(_task->dl, >dl);
> set_task_cpu(next_task, later_rq->cpu);
> add_rq_bw(_task->dl, _rq->dl);
> +
> +/*
> + * Update the later_rq clock here, because the clock is used
> + * by the cpufreq_update_util() inside __add_running_bw().
> + */
> +update_rq_clock(later_rq);
> add_running_bw(_task->dl, _rq->dl);
> -activate_task(later_rq, next_task, 0);
> +activate_task(later_rq, next_task, ENQUEUE_NOCLOCK);
> ret = 1;
>
> resched_curr(later_rq);
> >>>
> >>> Why isn't push_rt_task() affected by the very same issue?
> >>
> >> Aah, I see, its the add_running_bw() think; for which RT doesn't have a
> >> counter-part.
> >
> > Right, but doesn't enqueue_top_rt_rq end-up being called by activate_
> > task on lowest_rq? Mmm.
>
>
> AFAICS we have:
>
> push_rt_task() {
> activate_task() {
> enqueue_task(,,(flags=0)) {
> if (!(flags & ENQUEUE_NOCLOCK))
> update_rq_clock(rq);
> enqueue_task_rt() {
> enqueue_rt_entity() {
> enqueue_top_rt_rq();
> }
> }
> }
> }
>
> So we will have the clock updated already...
>
> Am I missing something?
Ah, indeed.
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On 07/20/2018 02:53 PM, Juri Lelli wrote:
> On 20/07/18 14:48, Peter Zijlstra wrote:
>> On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote:
>>> On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote:
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index fbfc3f1d368a..8b50eea4b607 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq)
sub_rq_bw(_task->dl, >dl);
set_task_cpu(next_task, later_rq->cpu);
add_rq_bw(_task->dl, _rq->dl);
+
+ /*
+ * Update the later_rq clock here, because the clock is used
+ * by the cpufreq_update_util() inside __add_running_bw().
+ */
+ update_rq_clock(later_rq);
add_running_bw(_task->dl, _rq->dl);
- activate_task(later_rq, next_task, 0);
+ activate_task(later_rq, next_task, ENQUEUE_NOCLOCK);
ret = 1;
resched_curr(later_rq);
>>>
>>> Why isn't push_rt_task() affected by the very same issue?
>>
>> Aah, I see, its the add_running_bw() think; for which RT doesn't have a
>> counter-part.
>
> Right, but doesn't enqueue_top_rt_rq end-up being called by activate_
> task on lowest_rq? Mmm.
AFAICS we have:
push_rt_task() {
activate_task() {
enqueue_task(,,(flags=0)) {
if (!(flags & ENQUEUE_NOCLOCK))
update_rq_clock(rq);
enqueue_task_rt() {
enqueue_rt_entity() {
enqueue_top_rt_rq();
}
}
}
}
So we will have the clock updated already...
Am I missing something?
Thanks,
-- Daniel
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On 07/20/2018 02:53 PM, Juri Lelli wrote:
> On 20/07/18 14:48, Peter Zijlstra wrote:
>> On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote:
>>> On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote:
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index fbfc3f1d368a..8b50eea4b607 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq)
sub_rq_bw(_task->dl, >dl);
set_task_cpu(next_task, later_rq->cpu);
add_rq_bw(_task->dl, _rq->dl);
+
+ /*
+ * Update the later_rq clock here, because the clock is used
+ * by the cpufreq_update_util() inside __add_running_bw().
+ */
+ update_rq_clock(later_rq);
add_running_bw(_task->dl, _rq->dl);
- activate_task(later_rq, next_task, 0);
+ activate_task(later_rq, next_task, ENQUEUE_NOCLOCK);
ret = 1;
resched_curr(later_rq);
>>>
>>> Why isn't push_rt_task() affected by the very same issue?
>>
>> Aah, I see, its the add_running_bw() think; for which RT doesn't have a
>> counter-part.
>
> Right, but doesn't enqueue_top_rt_rq end-up being called by activate_
> task on lowest_rq? Mmm.
AFAICS we have:
push_rt_task() {
activate_task() {
enqueue_task(,,(flags=0)) {
if (!(flags & ENQUEUE_NOCLOCK))
update_rq_clock(rq);
enqueue_task_rt() {
enqueue_rt_entity() {
enqueue_top_rt_rq();
}
}
}
}
So we will have the clock updated already...
Am I missing something?
Thanks,
-- Daniel
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On 20/07/18 14:48, Peter Zijlstra wrote: > On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote: > > On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > > index fbfc3f1d368a..8b50eea4b607 100644 > > > --- a/kernel/sched/deadline.c > > > +++ b/kernel/sched/deadline.c > > > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > > > sub_rq_bw(_task->dl, >dl); > > > set_task_cpu(next_task, later_rq->cpu); > > > add_rq_bw(_task->dl, _rq->dl); > > > + > > > + /* > > > + * Update the later_rq clock here, because the clock is used > > > + * by the cpufreq_update_util() inside __add_running_bw(). > > > + */ > > > + update_rq_clock(later_rq); > > > add_running_bw(_task->dl, _rq->dl); > > > - activate_task(later_rq, next_task, 0); > > > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > > > ret = 1; > > > > > > resched_curr(later_rq); > > > > Why isn't push_rt_task() affected by the very same issue? > > Aah, I see, its the add_running_bw() think; for which RT doesn't have a > counter-part. Right, but doesn't enqueue_top_rt_rq end-up being called by activate_ task on lowest_rq? Mmm.
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On 20/07/18 14:48, Peter Zijlstra wrote: > On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote: > > On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > > index fbfc3f1d368a..8b50eea4b607 100644 > > > --- a/kernel/sched/deadline.c > > > +++ b/kernel/sched/deadline.c > > > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > > > sub_rq_bw(_task->dl, >dl); > > > set_task_cpu(next_task, later_rq->cpu); > > > add_rq_bw(_task->dl, _rq->dl); > > > + > > > + /* > > > + * Update the later_rq clock here, because the clock is used > > > + * by the cpufreq_update_util() inside __add_running_bw(). > > > + */ > > > + update_rq_clock(later_rq); > > > add_running_bw(_task->dl, _rq->dl); > > > - activate_task(later_rq, next_task, 0); > > > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > > > ret = 1; > > > > > > resched_curr(later_rq); > > > > Why isn't push_rt_task() affected by the very same issue? > > Aah, I see, its the add_running_bw() think; for which RT doesn't have a > counter-part. Right, but doesn't enqueue_top_rt_rq end-up being called by activate_ task on lowest_rq? Mmm.
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote: > On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > index fbfc3f1d368a..8b50eea4b607 100644 > > --- a/kernel/sched/deadline.c > > +++ b/kernel/sched/deadline.c > > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > > sub_rq_bw(_task->dl, >dl); > > set_task_cpu(next_task, later_rq->cpu); > > add_rq_bw(_task->dl, _rq->dl); > > + > > + /* > > +* Update the later_rq clock here, because the clock is used > > +* by the cpufreq_update_util() inside __add_running_bw(). > > +*/ > > + update_rq_clock(later_rq); > > add_running_bw(_task->dl, _rq->dl); > > - activate_task(later_rq, next_task, 0); > > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > > ret = 1; > > > > resched_curr(later_rq); > > Why isn't push_rt_task() affected by the very same issue? Aah, I see, its the add_running_bw() think; for which RT doesn't have a counter-part.
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On Fri, Jul 20, 2018 at 02:46:15PM +0200, Peter Zijlstra wrote: > On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > > index fbfc3f1d368a..8b50eea4b607 100644 > > --- a/kernel/sched/deadline.c > > +++ b/kernel/sched/deadline.c > > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > > sub_rq_bw(_task->dl, >dl); > > set_task_cpu(next_task, later_rq->cpu); > > add_rq_bw(_task->dl, _rq->dl); > > + > > + /* > > +* Update the later_rq clock here, because the clock is used > > +* by the cpufreq_update_util() inside __add_running_bw(). > > +*/ > > + update_rq_clock(later_rq); > > add_running_bw(_task->dl, _rq->dl); > > - activate_task(later_rq, next_task, 0); > > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > > ret = 1; > > > > resched_curr(later_rq); > > Why isn't push_rt_task() affected by the very same issue? Aah, I see, its the add_running_bw() think; for which RT doesn't have a counter-part.
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index fbfc3f1d368a..8b50eea4b607 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > sub_rq_bw(_task->dl, >dl); > set_task_cpu(next_task, later_rq->cpu); > add_rq_bw(_task->dl, _rq->dl); > + > + /* > + * Update the later_rq clock here, because the clock is used > + * by the cpufreq_update_util() inside __add_running_bw(). > + */ > + update_rq_clock(later_rq); > add_running_bw(_task->dl, _rq->dl); > - activate_task(later_rq, next_task, 0); > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > ret = 1; > > resched_curr(later_rq); Why isn't push_rt_task() affected by the very same issue?
Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task
On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index fbfc3f1d368a..8b50eea4b607 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > sub_rq_bw(_task->dl, >dl); > set_task_cpu(next_task, later_rq->cpu); > add_rq_bw(_task->dl, _rq->dl); > + > + /* > + * Update the later_rq clock here, because the clock is used > + * by the cpufreq_update_util() inside __add_running_bw(). > + */ > + update_rq_clock(later_rq); > add_running_bw(_task->dl, _rq->dl); > - activate_task(later_rq, next_task, 0); > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > ret = 1; > > resched_curr(later_rq); Why isn't push_rt_task() affected by the very same issue?
