From 15a8641eadb492ef7c5489faa25256967bdfd303 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 19 Jun 2008 09:06:59 +0200 Subject: [PATCH] sched: rt-group: fix RR buglet In tick_task_rt() we first call update_curr_rt() which can dequeue a runqueue due to it running out of runtime, and then we try to requeue it, of it also having exhausted its RR quota. Obviously requeueing something that is no longer on the runqueue will not have the expected result. Signed-off-by: Peter Zijlstra Tested-by: Daniel K. Signed-off-by: Ingo Molnar --- kernel/sched_rt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 837241568d..1dad5bbb59 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -549,8 +549,10 @@ static void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) { struct rt_prio_array *array = &rt_rq->active; + struct list_head *queue = array->queue + rt_se_prio(rt_se); - list_move_tail(&rt_se->run_list, array->queue + rt_se_prio(rt_se)); + if (on_rt_rq(rt_se)) + list_move_tail(&rt_se->run_list, queue); } static void requeue_task_rt(struct rq *rq, struct task_struct *p) -- 2.39.5