From 07a47f9da976cfe523f7f413ca7551fdc0613a4c Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Thu, 10 Sep 2009 14:40:57 +0200
Subject: [PATCH] --- yaml --- r: 162999 b: refs/heads/master c:
 ae154be1f34a674e6cbb43ccf6e442f56acd7a70 h: refs/heads/master i:   162997:
 c43d7b1bc219f25596bb4b865c9ee7ecc37e168e   162995:
 43627d99ac62465a08ce6f23b6eb922def76cef3   162991:
 e9637286736752ab53d993c9cb1a8bbac2952dbc v: v3

---
 [refs]                    |  2 +-
 trunk/kernel/sched.c      | 40 +++++++++++++++++++--------------------
 trunk/kernel/sched_fair.c | 21 +++++++++++++++++---
 3 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/[refs] b/[refs]
index 97de2b1baf20..f06a40b840dd 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c88d5910890ad35af283344417891344604f0438
+refs/heads/master: ae154be1f34a674e6cbb43ccf6e442f56acd7a70
diff --git a/trunk/kernel/sched.c b/trunk/kernel/sched.c
index 6c819f338b11..f0ccb8b926c8 100644
--- a/trunk/kernel/sched.c
+++ b/trunk/kernel/sched.c
@@ -1538,6 +1538,26 @@ static unsigned long target_load(int cpu, int type)
 	return max(rq->cpu_load[type-1], total);
 }
 
+static struct sched_group *group_of(int cpu)
+{
+	struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd);
+
+	if (!sd)
+		return NULL;
+
+	return sd->groups;
+}
+
+static unsigned long power_of(int cpu)
+{
+	struct sched_group *group = group_of(cpu);
+
+	if (!group)
+		return SCHED_LOAD_SCALE;
+
+	return group->cpu_power;
+}
+
 static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
 
 static unsigned long cpu_avg_load_per_task(int cpu)
@@ -3982,26 +4002,6 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 	return NULL;
 }
 
-static struct sched_group *group_of(int cpu)
-{
-	struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd);
-
-	if (!sd)
-		return NULL;
-
-	return sd->groups;
-}
-
-static unsigned long power_of(int cpu)
-{
-	struct sched_group *group = group_of(cpu);
-
-	if (!group)
-		return SCHED_LOAD_SCALE;
-
-	return group->cpu_power;
-}
-
 /*
  * find_busiest_queue - find the busiest runqueue among the cpus in group.
  */
diff --git a/trunk/kernel/sched_fair.c b/trunk/kernel/sched_fair.c
index 09d19f77eb3a..eaa00014b499 100644
--- a/trunk/kernel/sched_fair.c
+++ b/trunk/kernel/sched_fair.c
@@ -1333,10 +1333,25 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync)
 
 	for_each_domain(cpu, tmp) {
 		/*
-		 * If power savings logic is enabled for a domain, stop there.
+		 * If power savings logic is enabled for a domain, see if we
+		 * are not overloaded, if so, don't balance wider.
 		 */
-		if (tmp->flags & SD_POWERSAVINGS_BALANCE)
-			break;
+		if (tmp->flags & SD_POWERSAVINGS_BALANCE) {
+			unsigned long power = 0;
+			unsigned long nr_running = 0;
+			unsigned long capacity;
+			int i;
+
+			for_each_cpu(i, sched_domain_span(tmp)) {
+				power += power_of(i);
+				nr_running += cpu_rq(i)->cfs.nr_running;
+			}
+
+			capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE);
+
+			if (nr_running/2 < capacity)
+				break;
+		}
 
 		switch (flag) {
 		case SD_BALANCE_WAKE: