From f1d703449a981bb481fe31f37782e96d6098eaf4 Mon Sep 17 00:00:00 2001 From: stable-bot for Steven Rostedt Date: Thu, 10 Feb 2011 10:21:08 +0100 Subject: sched: Give CPU bound RT tasks preference From:: Steven Rostedt Commit: b3bc211cfe7d5fe94b310480d78e00bea96fbf2a upstream If a high priority task is waking up on a CPU that is running a lower priority task that is bound to a CPU, see if we can move the high RT task to another CPU first. Note, if all other CPUs are running higher priority tasks than the CPU bounded current task, then it will be preempted regardless. Signed-off-by: Steven Rostedt Signed-off-by: Peter Zijlstra Cc: Gregory Haskins LKML-Reference: <20100921024138.888922071@goodmis.org> Signed-off-by: Ingo Molnar Signed-off-by: Mike Galbraith Acked-by: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman --- kernel/sched_rt.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index d2d481f53040..3782369ed6f5 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -965,7 +965,8 @@ select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags) * For equal prio tasks, we just let the scheduler sort it out. */ if (unlikely(rt_task(rq->curr)) && - rq->curr->prio < p->prio && + (rq->curr->rt.nr_cpus_allowed < 2 || + rq->curr->prio < p->prio) && (p->rt.nr_cpus_allowed > 1)) { int cpu = find_lowest_rq(p); @@ -1493,9 +1494,10 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p) if (!task_running(rq, p) && !test_tsk_need_resched(rq->curr) && has_pushable_tasks(rq) && + p->rt.nr_cpus_allowed > 1 && rt_task(rq->curr) && - rq->curr->prio < p->prio && - p->rt.nr_cpus_allowed > 1) + (rq->curr->rt.nr_cpus_allowed < 2 || + rq->curr->prio < p->prio)) push_rt_tasks(rq); } -- cgit v1.2.3