sched/deadline: Remove unnecessary condition in push_dl_task()

pick_next_pushable_dl_task(rq) has BUG_ON(rq->cpu != task_cpu(task))
when it returns a task other than NULL, which means that task_cpu(task)
must be rq->cpu. So if task == next_task, then task_cpu(next_task) must
be rq->cpu as well. Remove the redundant condition and make the code simpler.

This way one unnecessary branch and two LOAD operations can be avoided.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551159-22367-1-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index a2ce59015642c3ccc753006837a9485b2d9fbcd3..df6c2912bd605b34cfe0a44ea64515d09ace18bf 100644 (file)
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1533,7 +1533,7 @@ retry:
                 * then possible that next_task has migrated.
                 */
                task = pick_next_pushable_dl_task(rq);
-               if (task_cpu(next_task) == rq->cpu && task == next_task) {
+               if (task == next_task) {
                        /*
                         * The task is still there. We don't try
                         * again, some other cpu will pull it when ready.