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Commit b3bc211cfe7d5fe94b310480d78e00bea96fbf2a

Authored by Steven Rostedt
Committed by Ingo Molnar
1 parent 43fa5460fe
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

sched: Give CPU bound RT tasks preference 

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>

Showing 1 changed file with 5 additions and 3 deletions Side-by-side Diff

... ... @@ -971,7 +971,8 @@
971 971 * For equal prio tasks, we just let the scheduler sort it out.
972 972 */
973 973 if (unlikely(rt_task(rq->curr)) &&
974   - rq->curr->prio < p->prio &&
  974 + (rq->curr->rt.nr_cpus_allowed < 2 ||
  975 + rq->curr->prio < p->prio) &&
975 976 (p->rt.nr_cpus_allowed > 1)) {
976 977 int cpu = find_lowest_rq(p);
977 978  
978 979  
... ... @@ -1491,9 +1492,10 @@
1491 1492 if (!task_running(rq, p) &&
1492 1493 !test_tsk_need_resched(rq->curr) &&
1493 1494 has_pushable_tasks(rq) &&
  1495 + p->rt.nr_cpus_allowed > 1 &&
1494 1496 rt_task(rq->curr) &&
1495   - rq->curr->prio < p->prio &&
1496   - p->rt.nr_cpus_allowed > 1)
  1497 + (rq->curr->rt.nr_cpus_allowed < 2 ||
  1498 + rq->curr->prio < p->prio))
1497 1499 push_rt_tasks(rq);
1498 1500 }
1499 1501