Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | "zhaoxiu.zeng" <> | Subject | [PATCH] schedule: SCHED_RR: Give a fresh time-slice to the task after after it suspends or relinquishes | Date | Wed, 22 Dec 2021 17:15:26 +0800 |
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Assuming the sched_rr_timeslice is 100ms, there are several tasks with the same priority t1, t2, t3, ..., and t1 sleeps every 80ms, the scheduling timing may be: t1 t2 t3 t1 t2 t3 t1 t2 t3 t1 t2 t3 80, 100, 100, ..., 20, 100, 100, ..., 60, 100, 100, ..., 40, 100, 100
After applying this patch, the scheduling timing may be: t1 t2 t3 t1 t2 t3 t1 t2 t3 t1 t2 t3 80, 100, 100, ..., 80, 100, 100, ..., 80, 100, 100, ..., 80, 100, 100
Signed-off-by: zhaoxiu.zeng <zhaoxiu.zeng@gmail.com> --- kernel/sched/rt.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index b48baaba2fc2..51798fefcb36 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1491,9 +1491,13 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int flags) { struct sched_rt_entity *rt_se = &p->rt; - if (flags & ENQUEUE_WAKEUP) + if (flags & ENQUEUE_WAKEUP) { rt_se->timeout = 0; + if (p->policy == SCHED_RR) + p->rt.time_slice = sched_rr_timeslice; + } + check_schedstat_required(); update_stats_wait_start_rt(rt_rq_of_se(rt_se), rt_se); @@ -1544,7 +1548,12 @@ static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) static void yield_task_rt(struct rq *rq) { - requeue_task_rt(rq, rq->curr, 0); + struct task_struct *p = rq->curr; + + if (p->policy == SCHED_RR) + p->rt.time_slice = sched_rr_timeslice; + + requeue_task_rt(rq, p, 0); } #ifdef CONFIG_SMP -- 2.32.0
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