path: root/kernel/sched_rt.c
diff options
authorGregory Haskins <ghaskins@novell.com>2008-01-25 21:08:09 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-25 21:08:09 +0100
commite7693a362ec84bb5b6fd441d8a8b4b9d568a7a0c (patch)
tree078940540641a59aaf199695bfc6de3f062a987b /kernel/sched_rt.c
parentsched: clean up this_rq use in kernel/sched_rt.c (diff)
sched: de-SCHED_OTHER-ize the RT path
The current wake-up code path tries to determine if it can optimize the wake-up to "this_cpu" by computing load calculations. The problem is that these calculations are only relevant to SCHED_OTHER tasks where load is king. For RT tasks, priority is king. So the load calculation is completely wasted bandwidth. Therefore, we create a new sched_class interface to help with pre-wakeup routing decisions and move the load calculation as a function of CFS task's class. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to '')
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index b788e35ffd3f..5de1aebdbd1b 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -150,6 +150,13 @@ yield_task_rt(struct rq *rq)
requeue_task_rt(rq, rq->curr);
+#ifdef CONFIG_SMP
+static int select_task_rq_rt(struct task_struct *p, int sync)
+ return task_cpu(p);
+#endif /* CONFIG_SMP */
* Preempt the current task with a newly woken task if needed:
@@ -667,6 +674,9 @@ const struct sched_class rt_sched_class = {
.enqueue_task = enqueue_task_rt,
.dequeue_task = dequeue_task_rt,
.yield_task = yield_task_rt,
+#ifdef CONFIG_SMP
+ .select_task_rq = select_task_rq_rt,
+#endif /* CONFIG_SMP */
.check_preempt_curr = check_preempt_curr_rt,