sched: Give CPU bound RT tasks preference

From:: Steven Rostedt <srostedt@redhat.com>

Commit: b3bc211cfe 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 <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gregory Haskins <ghaskins@novell.com>
LKML-Reference: <20100921024138.888922071@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
stable-bot for Steven Rostedt
2011-02-10 10:21:08 +01:00
committed by Greg Kroah-Hartman
parent f266611ef3
commit f1d703449a

View File

@@ -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);
}