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authorDmitry Adamushko <dmitry.adamushko@gmail.com>2007-10-15 17:00:08 +0200
committerIngo Molnar <mingo@elte.hu>2007-10-15 17:00:08 +0200
commit87fefa381ef27f46c1182622ea01eb9504cd2e24 (patch)
tree036336afad61898307bd3699ecdc3bcbdc3850b6
parent75d4ef16a6aa84f708188bada182315f80aab6fa (diff)
downloadlinux-2.6.34-ux500-87fefa381ef27f46c1182622ea01eb9504cd2e24.tar.gz
sched: optimize task_new_fair()
due to the fact that we no longer keep the 'current' within the tree, dequeue/enqueue_entity() is useless for the 'current' in task_new_fair(). We are about to reschedule and sched_class->put_prev_task() will put the 'current' back into the tree, based on its new key. text data bss dec hex filename 24388 2734 20 27142 6a06 sched.o.before 24341 2734 20 27095 69d7 sched.o.after Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--kernel/sched_fair.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index b9e426a8a09..827a0636525 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -972,10 +972,11 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
if (sysctl_sched_child_runs_first &&
curr->vruntime < se->vruntime) {
-
- dequeue_entity(cfs_rq, curr, 0);
+ /*
+ * Upon rescheduling, sched_class::put_prev_task() will place
+ * 'current' within the tree based on its new key value.
+ */
swap(curr->vruntime, se->vruntime);
- enqueue_entity(cfs_rq, curr, 0);
}
update_stats_enqueue(cfs_rq, se);