hrtimer: speedup hrtimer_enqueue
Speedup hrtimer_enqueue by evaluating the rbtree insertion result.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 065a897..eb1ddeb 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -686,6 +686,7 @@
struct rb_node **link = &base->active.rb_node;
struct rb_node *parent = NULL;
struct hrtimer *entry;
+ int leftmost = 1;
/*
* Find the right place in the rbtree:
@@ -697,18 +698,19 @@
* We dont care about collisions. Nodes with
* the same expiry time stay together.
*/
- if (timer->expires.tv64 < entry->expires.tv64)
+ if (timer->expires.tv64 < entry->expires.tv64) {
link = &(*link)->rb_left;
- else
+ } else {
link = &(*link)->rb_right;
+ leftmost = 0;
+ }
}
/*
* Insert the timer to the rbtree and check whether it
* replaces the first pending timer
*/
- if (!base->first || timer->expires.tv64 <
- rb_entry(base->first, struct hrtimer, node)->expires.tv64) {
+ if (leftmost) {
/*
* Reprogram the clock event device. When the timer is already
* expired hrtimer_enqueue_reprogram has either called the
