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)
setup_new_dl_entity(&p->dl);
if (rq->curr != p) {
--
