From 7f0c8e5df90b28d6cbd716742051edce53ad5132 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Date: Sat, 21 May 2011 12:58:28 +0200
Subject: [PATCH] --- yaml --- r: 253180 b: refs/heads/master c:
 1c3cc11602111d1318c2a5743bd2e88c82813927 h: refs/heads/master v: v3

---
 [refs]               |  2 +-
 trunk/kernel/timer.c | 15 +++++++--------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index fb36317b1f20..24d60ad19f0c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1b054b67d3bfc6dca9f634c104780f3f24ff3eec
+refs/heads/master: 1c3cc11602111d1318c2a5743bd2e88c82813927
diff --git a/trunk/kernel/timer.c b/trunk/kernel/timer.c
index fd6198692b57..8cff36119e4d 100644
--- a/trunk/kernel/timer.c
+++ b/trunk/kernel/timer.c
@@ -749,16 +749,15 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
 	unsigned long expires_limit, mask;
 	int bit;
 
-	expires_limit = expires;
-
 	if (timer->slack >= 0) {
 		expires_limit = expires + timer->slack;
 	} else {
-		unsigned long now = jiffies;
+		long delta = expires - jiffies;
+
+		if (delta < 256)
+			return expires;
 
-		/* No slack, if already expired else auto slack 0.4% */
-		if (time_after(expires, now))
-			expires_limit = expires + (expires - now)/256;
+		expires_limit = expires + delta / 256;
 	}
 	mask = expires ^ expires_limit;
 	if (mask == 0)
@@ -795,6 +794,8 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
  */
 int mod_timer(struct timer_list *timer, unsigned long expires)
 {
+	expires = apply_slack(timer, expires);
+
 	/*
 	 * This is a common optimization triggered by the
 	 * networking code - if the timer is re-modified
@@ -803,8 +804,6 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
 	if (timer_pending(timer) && timer->expires == expires)
 		return 1;
 
-	expires = apply_slack(timer, expires);
-
 	return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
 }
 EXPORT_SYMBOL(mod_timer);