Messages in this thread Patch in this message | | | From | Byungchul Park <> | Subject | [PATCH v3 2/2] sched/rt: Remove unnecessary condition in push_rt_task() | Date | Thu, 16 Feb 2017 11:34:17 +0900 |
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pick_next_pushable_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 code simpler.
By this patch, unnecessary one branch and two LOAD operations in 'if' statement can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Juri Lelli <juri.lelli@arm.com> --- kernel/sched/rt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 4101f9d..5abd9a52 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1820,7 +1820,7 @@ static int push_rt_task(struct rq *rq) * pushing. */ task = pick_next_pushable_task(rq); - if (task_cpu(next_task) == rq->cpu && task == next_task) { + if (task == next_task) { /* * The task hasn't migrated, and is still the next * eligible task, but we failed to find a run-queue -- 1.9.1
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