From f3ed5c1387b2e1df3a8a99b784cd252f3e0beedd Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Wed, 16 Sep 2009 08:54:45 +0200
Subject: [PATCH] --- yaml --- r: 163017 b: refs/heads/master c:
 51e0304ce6e55a6e59658558916b4f74da085ff0 h: refs/heads/master i:   163015:
 10db5ab3975c4da698fb024f666374fe7d090743 v: v3

---
 [refs]                        | 2 +-
 trunk/kernel/sched_fair.c     | 9 ++++++++-
 trunk/kernel/sched_features.h | 9 ++++++++-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index f7a2e11ba56c..4a70c4d979a3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 59abf02644c45f1591e1374ee7bb45dc757fcb88
+refs/heads/master: 51e0304ce6e55a6e59658558916b4f74da085ff0
diff --git a/trunk/kernel/sched_fair.c b/trunk/kernel/sched_fair.c
index a37f311f436e..acf16a8d934b 100644
--- a/trunk/kernel/sched_fair.c
+++ b/trunk/kernel/sched_fair.c
@@ -711,7 +711,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 
 	if (!initial) {
 		/* sleeps upto a single latency don't count. */
-		if (sched_feat(NEW_FAIR_SLEEPERS)) {
+		if (sched_feat(FAIR_SLEEPERS)) {
 			unsigned long thresh = sysctl_sched_latency;
 
 			/*
@@ -725,6 +725,13 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 					 task_of(se)->policy != SCHED_IDLE))
 				thresh = calc_delta_fair(thresh, se);
 
+			/*
+			 * Halve their sleep time's effect, to allow
+			 * for a gentler effect of sleepers:
+			 */
+			if (sched_feat(GENTLE_FAIR_SLEEPERS))
+				thresh >>= 1;
+
 			vruntime -= thresh;
 		}
 	}
diff --git a/trunk/kernel/sched_features.h b/trunk/kernel/sched_features.h
index 70115c69c7a9..fd375675f834 100644
--- a/trunk/kernel/sched_features.h
+++ b/trunk/kernel/sched_features.h
@@ -3,7 +3,14 @@
  * considers the task to be running during that period. This gives it
  * a service deficit on wakeup, allowing it to run sooner.
  */
-SCHED_FEAT(NEW_FAIR_SLEEPERS, 0)
+SCHED_FEAT(FAIR_SLEEPERS, 1)
+
+/*
+ * Only give sleepers 50% of their service deficit. This allows
+ * them to run sooner, but does not allow tons of sleepers to
+ * rip the spread apart.
+ */
+SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
 
 /*
  * By not normalizing the sleep time, heavy tasks get an effective