From a7bebf488791aa1036f3e6629daf01d01f705dcb Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Wed, 26 Nov 2014 08:44:01 +0800 Subject: [PATCH] sched/deadline: Fix hrtick for a non-leftmost task After update_curr_dl() the current task might not be the leftmost task anymore. In that case do not start a new hrtick for it. In this case NEED_RESCHED will be set and the next schedule will start the hrtick for the new task if and when appropriate. Signed-off-by: Wanpeng Li Acked-by: Juri Lelli [ Rewrote the changelog and comment. ] Signed-off-by: Peter Zijlstra (Intel) Cc: Kirill Tkhai Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1416962647-76792-2-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index e0e9c2986976..7b684f9341a5 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1073,7 +1073,13 @@ static void task_tick_dl(struct rq *rq, struct task_struct *p, int queued) { update_curr_dl(rq); - if (hrtick_enabled(rq) && queued && p->dl.runtime > 0) + /* + * Even when we have runtime, update_curr_dl() might have resulted in us + * not being the leftmost task anymore. In that case NEED_RESCHED will + * be set and schedule() will start a new hrtick for the next task. + */ + if (hrtick_enabled(rq) && queued && p->dl.runtime > 0 && + is_leftmost(p, &rq->dl)) start_hrtick_dl(rq, p); } -- GitLab