linux-kernel - [patch v3 7/8] sched: consider runnable load average in effective

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Date:	Tue,  2 Apr 2013 11:23:27 +0800
From:	Alex Shi <alex.shi@...el.com>
To:	mingo@...hat.com, peterz@...radead.org, tglx@...utronix.de,
	akpm@...ux-foundation.org, arjan@...ux.intel.com, bp@...en8.de,
	pjt@...gle.com, namhyung@...nel.org, efault@....de,
	morten.rasmussen@....com
Cc:	vincent.guittot@...aro.org, gregkh@...uxfoundation.org,
	preeti@...ux.vnet.ibm.com, viresh.kumar@...aro.org,
	linux-kernel@...r.kernel.org, alex.shi@...el.com,
	len.brown@...el.com, rafael.j.wysocki@...el.com, jkosina@...e.cz,
	clark.williams@...il.com, tony.luck@...el.com,
	keescook@...omium.org, mgorman@...e.de, riel@...hat.com
Subject: [patch v3 7/8] sched: consider runnable load average in effective_load

effective_load calculates the load change as seen from the
root_task_group. It needs to engage the runnable average
of changed task.

Thanks for Morten Rasmussen's reminder of this.

Signed-off-by: Alex Shi <alex.shi@...el.com>
---
 kernel/sched/fair.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index bf4e0d4..fdb88de 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2976,7 +2976,8 @@ static void task_waking_fair(struct task_struct *p)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 /*
- * effective_load() calculates the load change as seen from the root_task_group
+ * effective_load() calculates the runnable load average change as seen from
+ * the root_task_group
  *
  * Adding load to a group doesn't make a group heavier, but can cause movement
  * of group shares between cpus. Assuming the shares were perfectly aligned one
@@ -3024,6 +3025,9 @@ static void task_waking_fair(struct task_struct *p)
  * Therefore the effective change in loads on CPU 0 would be 5/56 (3/8 - 2/7)
  * times the weight of the group. The effect on CPU 1 would be -4/56 (4/8 -
  * 4/7) times the weight of the group.
+ *
+ * After get effective_load of the load moving, will engaged the sched entity's
+ * runnable avg.
  */
 static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
 {
@@ -3098,6 +3102,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 	struct task_group *tg;
 	unsigned long weight;
 	int balanced;
+	int runnable_avg;
 
 	idx	  = sd->wake_idx;
 	this_cpu  = smp_processor_id();
@@ -3113,13 +3118,19 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 	if (sync) {
 		tg = task_group(current);
 		weight = current->se.load.weight;
+		runnable_avg = current->se.avg.runnable_avg_sum * NICE_0_LOAD
+				/ (current->se.avg.runnable_avg_period + 1);
 
-		this_load += effective_load(tg, this_cpu, -weight, -weight);
-		load += effective_load(tg, prev_cpu, 0, -weight);
+		this_load += effective_load(tg, this_cpu, -weight, -weight)
+				* runnable_avg >> NICE_0_SHIFT;
+		load += effective_load(tg, prev_cpu, 0, -weight)
+				* runnable_avg >> NICE_0_SHIFT;
 	}
 
 	tg = task_group(p);
 	weight = p->se.load.weight;
+	runnable_avg = p->se.avg.runnable_avg_sum * NICE_0_LOAD
+				/ (p->se.avg.runnable_avg_period + 1);
 
 	/*
 	 * In low-load situations, where prev_cpu is idle and this_cpu is idle
@@ -3131,16 +3142,18 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 	 * task to be woken on this_cpu.
 	 */
 	if (this_load > 0) {
-		s64 this_eff_load, prev_eff_load;
+		s64 this_eff_load, prev_eff_load, tmp_eff_load;
 
 		this_eff_load = 100;
 		this_eff_load *= power_of(prev_cpu);
-		this_eff_load *= this_load +
-			effective_load(tg, this_cpu, weight, weight);
+		tmp_eff_load = effective_load(tg, this_cpu, weight, weight)
+				* runnable_avg >> NICE_0_SHIFT;
+		this_eff_load *= this_load + tmp_eff_load;
 
 		prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
 		prev_eff_load *= power_of(this_cpu);
-		prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight);
+		prev_eff_load *= load + (effective_load(tg, prev_cpu, 0, weight)
+						* runnable_avg >> NICE_0_SHIFT);
 
 		balanced = this_eff_load <= prev_eff_load;
 	} else
-- 
1.7.12

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