[PATCH] sched/deadline: fix artificial overrun introduced by yield_task_dl

[Juri Lelli]

Signed-off-by: Juri Lelli <juri.lelli@xxxxxxx>
---
 kernel/sched/deadline.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 2e31a30..db6ad38 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -633,7 +633,7 @@ static void update_curr_dl(struct rq *rq)
 
 	sched_rt_avg_update(rq, delta_exec);
 
-	dl_se->runtime -= delta_exec;
+	dl_se->runtime -= dl_se->dl_yielded ? 0 : delta_exec;
 	if (dl_runtime_exceeded(rq, dl_se)) {
 		__dequeue_task_dl(rq, curr, 0);
 		if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted)))
-- 
2.1.2

> Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx>
> ---
>  kernel/sched/deadline.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> index abfaf3d..d4ffc1e 100644
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -568,7 +568,12 @@ static
>  int dl_runtime_exceeded(struct rq *rq, struct sched_dl_entity *dl_se)
>  {
>  	int dmiss = dl_time_before(dl_se->deadline, rq_clock(rq));
> -	int rorun = dl_se->runtime <= 0;
> +	int rorun;
> +
> +	if (dl_se->dl_yielded && dl_se->runtime > 0)
> +		dl_se->runtime = 0;
> +
> +	rorun = dl_se->runtime <= 0;
>  
>  	if (!rorun && !dmiss)
>  		return 0;
> @@ -897,10 +902,8 @@ static void yield_task_dl(struct rq *rq)
>  	 * it and the bandwidth timer will wake it up and will give it
>  	 * new scheduling parameters (thanks to dl_yielded=1).
>  	 */
> -	if (p->dl.runtime > 0) {
> +	if (p->dl.runtime > 0)
>  		rq->curr->dl.dl_yielded = 1;
> -		p->dl.runtime = 0;
> -	}
>  	update_curr_dl(rq);
>  }
>  
> 

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