Queued ticks are scheduled to match the budget, which means the budget is overall consumed and the dl task should be throttled. Dl task will be replenished immediately if fail to start a dl timer.
However, the curr maybe not the left most dl task in the rb tree any more after this immediately replenished and reschedule is needed. Start high-res preemption tick for this upcoming rescheduled dl task is not correct. This patch fix it by not starting high-res preemption tick for a non-running dl task. Signed-off-by: Wanpeng Li <[email protected]> --- kernel/sched/deadline.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 56674f6..2a6a5bb 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1090,7 +1090,8 @@ 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) + if (hrtick_enabled(rq) && queued && p->dl.runtime > 0 && + is_leftmost(p, &rq->dl)) start_hrtick_dl(rq, p); } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
