From: Chad Goodman <cgoodman@HP-EliteBook-2730p.(none)>
Date: Mon, 10 Dec 2012 06:12:18 +0000 (-0800)
Subject: SCHED: Improve the ->group_imb logic
X-Git-Url: https://ziggy471.com/git/gitweb.cgi?p=ziggy471-sgs3-jb.git;a=commitdiff;h=c3fcbb3250d0962d5422df34b6c5714183e2f769

SCHED: Improve the ->group_imb logic

Signed-off-by: Ziggy <ziggy@tardis.(none)>
---

--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2717,7 +2717,8 @@ static inline void update_sg_lb_stats(st
 			int local_group, const struct cpumask *cpus,
 			int *balance, struct sg_lb_stats *sgs)
 {
-	unsigned long load, max_cpu_load, min_cpu_load, max_nr_running;
+	unsigned long nr_running, max_nr_running, min_nr_running;
+	unsigned long load, max_cpu_load, min_cpu_load;
 	int i;
 	unsigned int balance_cpu = -1, first_idle_cpu = 0;
 	unsigned long avg_load_per_task = 0;
@@ -2729,10 +2730,13 @@ static inline void update_sg_lb_stats(st
 	max_cpu_load = 0;
 	min_cpu_load = ~0UL;
 	max_nr_running = 0;
+	min_nr_running = ~0UL;
 
 	for_each_cpu_and(i, sched_group_cpus(group), cpus) {
 		struct rq *rq = cpu_rq(i);
 
+		nr_running = rq->nr_running;
+
 		/* Bias balancing toward cpus of our domain */
 		if (local_group) {
 			if (idle_cpu(i) && !first_idle_cpu) {
@@ -2743,16 +2747,19 @@ static inline void update_sg_lb_stats(st
 			load = target_load(i, load_idx);
 		} else {
 			load = source_load(i, load_idx);
-			if (load > max_cpu_load) {
+			if (load > max_cpu_load)
 				max_cpu_load = load;
-				max_nr_running = rq->nr_running;
-			}
 			if (min_cpu_load > load)
 				min_cpu_load = load;
+
+			if (nr_running > max_nr_running)
+				max_nr_running = nr_running;
+			if (min_nr_running > nr_running)
+				min_nr_running = nr_running;
 		}
 
 		sgs->group_load += load;
-		sgs->sum_nr_running += rq->nr_running;
+		sgs->sum_nr_running += nr_running;
 		sgs->sum_weighted_load += weighted_cpuload(i);
 		if (idle_cpu(i))
 			sgs->idle_cpus++;
@@ -2787,7 +2794,8 @@ static inline void update_sg_lb_stats(st
 	if (sgs->sum_nr_running)
 		avg_load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
 
-	if ((max_cpu_load - min_cpu_load) >= avg_load_per_task && max_nr_running > 1)
+	if ((max_cpu_load - min_cpu_load) >= avg_load_per_task &&
+	    (max_nr_running - min_nr_running) > 1)
 		sgs->group_imb = 1;
 
 	sgs->group_capacity = DIV_ROUND_CLOSEST(group->sgp->power,