1)requeue_task_rt: check if entity's next and prev are not the same element.
This guarantees entity is queued and it is not the only in the prio list.
Return 1 if at least one rt_se from the stack was really requeued.
2)Remove on_rt_rq check from requeue_rt_entity() because it is useless now.
Furthermore, it doesn't handle single rt_se case.
3)Make pretty task_tick_rt() more pretty.
Signed-off-by: Kirill Tkhai <[email protected]>
CC: Steven Rostedt <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: Peter Zijlstra <[email protected]>
---
kernel/sched/rt.c | 49 +++++++++++++++++++++++--------------------------
1 files changed, 23 insertions(+), 26 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 01970c8..3213503 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1135,29 +1135,37 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
* Put task to the head or the end of the run list without the overhead of
* dequeue followed by enqueue.
*/
-static void
+static inline void
requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)
{
- if (on_rt_rq(rt_se)) {
- struct rt_prio_array *array = &rt_rq->active;
- struct list_head *queue = array->queue + rt_se_prio(rt_se);
+ struct rt_prio_array *array = &rt_rq->active;
+ struct list_head *queue = array->queue + rt_se_prio(rt_se);
- if (head)
- list_move(&rt_se->run_list, queue);
- else
- list_move_tail(&rt_se->run_list, queue);
- }
+ if (head)
+ list_move(&rt_se->run_list, queue);
+ else
+ list_move_tail(&rt_se->run_list, queue);
}
-static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
+static int requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
{
struct sched_rt_entity *rt_se = &p->rt;
- struct rt_rq *rt_rq;
+ int requeued = 0;
for_each_sched_rt_entity(rt_se) {
- rt_rq = rt_rq_of_se(rt_se);
- requeue_rt_entity(rt_rq, rt_se, head);
+ /*
+ * Requeue to the head or tail of prio queue if
+ * rt_se is queued and it is not the only element
+ */
+ if (rt_se->run_list.prev != rt_se->run_list.next) {
+ struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
+
+ requeue_rt_entity(rt_rq, rt_se, head);
+ requeued = 1;
+ }
}
+
+ return requeued;
}
static void yield_task_rt(struct rq *rq)
@@ -1912,8 +1920,6 @@ static void watchdog(struct rq *rq, struct task_struct *p)
static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
{
- struct sched_rt_entity *rt_se = &p->rt;
-
update_curr_rt(rq);
watchdog(rq, p);
@@ -1930,17 +1936,8 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
p->rt.time_slice = sched_rr_timeslice;
- /*
- * Requeue to the end of queue if we (and all of our ancestors) are the
- * only element on the queue
- */
- for_each_sched_rt_entity(rt_se) {
- if (rt_se->run_list.prev != rt_se->run_list.next) {
- requeue_task_rt(rq, p, 0);
- set_tsk_need_resched(p);
- return;
- }
- }
+ if (requeue_task_rt(rq, p, 0))
+ set_tsk_need_resched(p);
}
static void set_curr_task_rt(struct rq *rq)
Peter,
A blast from the past. I'm cleaning out my INBOX and I found this patch
under the rug. I know I had a holiday when it was sent (date is July 4th,
Yay! fireworks).
Anyway, there was no comments to it. What do you think.
I haven't reviewed it much but I have a small comment by doing a quick
review (embedded).
On Thu, 04 Jul 2013 03:02:19 +0400
Kirill Tkhai <[email protected]> wrote:
> 1)requeue_task_rt: check if entity's next and prev are not the same element.
> This guarantees entity is queued and it is not the only in the prio list.
> Return 1 if at least one rt_se from the stack was really requeued.
>
> 2)Remove on_rt_rq check from requeue_rt_entity() because it is useless now.
> Furthermore, it doesn't handle single rt_se case.
>
> 3)Make pretty task_tick_rt() more pretty.
>
> Signed-off-by: Kirill Tkhai <[email protected]>
> CC: Steven Rostedt <[email protected]>
> CC: Ingo Molnar <[email protected]>
> CC: Peter Zijlstra <[email protected]>
> ---
> kernel/sched/rt.c | 49 +++++++++++++++++++++++--------------------------
> 1 files changed, 23 insertions(+), 26 deletions(-)
> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index 01970c8..3213503 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -1135,29 +1135,37 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int flags)
> * Put task to the head or the end of the run list without the overhead of
> * dequeue followed by enqueue.
> */
> -static void
> +static inline void
No need for the "inline" here. It's only used once and it's static. Gcc
will inline it naturally.
-- Steve
> requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head)
> {
> - if (on_rt_rq(rt_se)) {
> - struct rt_prio_array *array = &rt_rq->active;
> - struct list_head *queue = array->queue + rt_se_prio(rt_se);
> + struct rt_prio_array *array = &rt_rq->active;
> + struct list_head *queue = array->queue + rt_se_prio(rt_se);
>
> - if (head)
> - list_move(&rt_se->run_list, queue);
> - else
> - list_move_tail(&rt_se->run_list, queue);
> - }
> + if (head)
> + list_move(&rt_se->run_list, queue);
> + else
> + list_move_tail(&rt_se->run_list, queue);
> }
>
> -static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
> +static int requeue_task_rt(struct rq *rq, struct task_struct *p, int head)
> {
> struct sched_rt_entity *rt_se = &p->rt;
> - struct rt_rq *rt_rq;
> + int requeued = 0;
>
> for_each_sched_rt_entity(rt_se) {
> - rt_rq = rt_rq_of_se(rt_se);
> - requeue_rt_entity(rt_rq, rt_se, head);
> + /*
> + * Requeue to the head or tail of prio queue if
> + * rt_se is queued and it is not the only element
> + */
> + if (rt_se->run_list.prev != rt_se->run_list.next) {
> + struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
> +
> + requeue_rt_entity(rt_rq, rt_se, head);
> + requeued = 1;
> + }
> }
> +
> + return requeued;
> }
>
> static void yield_task_rt(struct rq *rq)
> @@ -1912,8 +1920,6 @@ static void watchdog(struct rq *rq, struct task_struct *p)
>
> static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
> {
> - struct sched_rt_entity *rt_se = &p->rt;
> -
> update_curr_rt(rq);
>
> watchdog(rq, p);
> @@ -1930,17 +1936,8 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
>
> p->rt.time_slice = sched_rr_timeslice;
>
> - /*
> - * Requeue to the end of queue if we (and all of our ancestors) are the
> - * only element on the queue
> - */
> - for_each_sched_rt_entity(rt_se) {
> - if (rt_se->run_list.prev != rt_se->run_list.next) {
> - requeue_task_rt(rq, p, 0);
> - set_tsk_need_resched(p);
> - return;
> - }
> - }
> + if (requeue_task_rt(rq, p, 0))
> + set_tsk_need_resched(p);
> }
>
> static void set_curr_task_rt(struct rq *rq)