hrtimer: speedup hrtimer_enqueue

99bc2fcb · Ingo Molnar <[email protected]> · 2007-07-21 04:37:36 -07:00

Speedup hrtimer_enqueue by evaluating the rbtree insertion result.

Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: 99bc2fcb283852931fb6bbef40f3df8316b59000
Parents: 820de5c3

Changes

1 files changed · +6 −4

File	Status	Add	Del	Content
kernel/hrtimer.c	modified	+6	−4	View file

kernel/hrtimer.c

View file

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 @@ static void enqueue_hrtimer(struct hrtimer *timer,
 	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 @@ static void enqueue_hrtimer(struct hrtimer *timer,
 		 * 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