[PATCH] sched: update cpupri for runqueue when its priority changes

From: Hillf Danton
Date: Sun Jun 05 2011 - 05:54:12 EST


When the priority of runqueue changes, lower or higer, the info of cpupri
should be updated, in cases such as pick_next_task_rt() and switched_to_rt().

Signed-off-by: Hillf Danton <dhillf@xxxxxxxxx>
---
kernel/sched_rt.c | 11 ++++++++++-
1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 08e9374..9508168 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1158,6 +1158,8 @@ static struct task_struct
*pick_next_task_rt(struct rq *rq)
* lock again later if there is no need to push
*/
rq->post_schedule = has_pushable_tasks(rq);
+
+ cpupri_set(&rq->rd->cpupri, rq->cpu, p == NULL ? MAX_RT_PRIO : p->prio);
#endif

return p;
@@ -1673,6 +1675,8 @@ static void switched_to_rt(struct rq *rq, struct
task_struct *p)
{
int check_resched = 1;

+ if (!p->on_rq)
+ return;
/*
* If we are already running, then there's nothing
* that needs to be done. But if we are not running
@@ -1680,7 +1684,7 @@ static void switched_to_rt(struct rq *rq, struct
task_struct *p)
* If that current running task is also an RT task
* then see if we can move to another run queue.
*/
- if (p->on_rq && rq->curr != p) {
+ if (rq->curr != p) {
#ifdef CONFIG_SMP
if (rq->rt.overloaded && push_rt_task(rq) &&
/* Don't resched if we changed runqueues */
@@ -1690,6 +1694,11 @@ static void switched_to_rt(struct rq *rq,
struct task_struct *p)
if (check_resched && p->prio < rq->curr->prio)
resched_task(rq->curr);
}
+ else {
+#ifdef CONFIG_SMP
+ cpupri_set(&rq->rd->cpupri, rq->cpu, p->prio);
+#endif
+ }
}

/*
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