Commit: b3bc211cfe7d5fe94b310480d78e00bea96fbf2a upstream
Aauthor: Steven Rostedt <[email protected]>
AuthorDate: Mon Sep 20 22:40:04 2010 -0400
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 <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Gregory Haskins <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Mike Galbraith <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
---
kernel/sched_rt.c | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index d2d481f..3782369 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);
}
--
1.7.4