From: Dietmar Eggemann <dietmar.eggemann@arm.com>
Date: Sun, 4 Dec 2016 17:47:53 +0000 (+0000)
Subject: Revert "WIP: sched: Consider spare cpu capacity at task wake-up"
X-Git-Tag: release-20171130_firefly~4^2~100^2~76
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0339ac74d6cdf2afc391c8b2e0b85409c972cdaa;p=firefly-linux-kernel-4.4.55.git

Revert "WIP: sched: Consider spare cpu capacity at task wake-up"

This reverts commit 75a9695b619741019363f889c99c97c7bb823797.

Change-Id: I846b21f2bdeb0b0ca30ad65683564ed07a429428
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
[ minor merge changes ]
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index abe49df1e6f0..12bb2ae026f5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5509,10 +5509,9 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
 		  int this_cpu, int sd_flag)
 {
 	struct sched_group *idlest = NULL, *group = sd->groups;
-	struct sched_group *fit_group = NULL, *spare_group = NULL;
+	struct sched_group *fit_group = NULL;
 	unsigned long min_load = ULONG_MAX, this_load = 0;
 	unsigned long fit_capacity = ULONG_MAX;
-	unsigned long max_spare_capacity = capacity_margin - SCHED_LOAD_SCALE;
 	int load_idx = sd->forkexec_idx;
 	int imbalance = 100 + (sd->imbalance_pct-100)/2;
 
@@ -5520,7 +5519,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
 		load_idx = sd->wake_idx;
 
 	do {
-		unsigned long load, avg_load, spare_capacity;
+		unsigned long load, avg_load;
 		int local_group;
 		int i;
 
@@ -5552,16 +5551,6 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
 				fit_capacity = capacity_of(i);
 				fit_group = group;
 			}
-
-			/*
-			 * Look for group which has most spare capacity on a
-			 * single cpu.
-			 */
-			spare_capacity = capacity_of(i) - cpu_util(i);
-			if (spare_capacity > max_spare_capacity) {
-				max_spare_capacity = spare_capacity;
-				spare_group = group;
-			}
 		}
 
 		/* Adjust by relative CPU capacity of the group */
@@ -5578,9 +5567,6 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
 	if (fit_group)
 		return fit_group;
 
-	if (spare_group)
-		return spare_group;
-
 	if (!idlest || 100*this_load < imbalance*min_load)
 		return NULL;
 	return idlest;