sched: improve the scheduler

This change is for general scheduler improvement.

Change-Id: Iba464885e8b2172f955cfba3bd6d55743d790b32
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>

include/linux/sched/sysctl.h

@@ -41,7 +41,8 @@ extern unsigned int sysctl_sched_boost;
 extern unsigned int sysctl_sched_group_upmigrate_pct;
 extern unsigned int sysctl_sched_group_downmigrate_pct;
 extern unsigned int sysctl_sched_walt_rotate_big_tasks;
-extern unsigned int sysctl_sched_min_task_util_for_boost_colocation;
+extern unsigned int sysctl_sched_min_task_util_for_boost;
+extern unsigned int sysctl_sched_min_task_util_for_colocation;
 extern unsigned int sysctl_sched_little_cluster_coloc_fmin_khz;
 
 extern int

kernel/sched/fair.c

@@ -199,7 +199,9 @@ unsigned int sched_capacity_margin_down[NR_CPUS] = {
 
 #ifdef CONFIG_SCHED_WALT
 /* 1ms default for 20ms window size scaled to 1024 */
-unsigned int sysctl_sched_min_task_util_for_boost_colocation = 51;
+unsigned int sysctl_sched_min_task_util_for_boost = 51;
+/* 0.68ms default for 20ms window size scaled to 1024 */
+unsigned int sysctl_sched_min_task_util_for_colocation = 35;
 #endif
 
 static inline void update_load_add(struct load_weight *lw, unsigned long inc)
@@ -7953,6 +7955,15 @@ static inline int wake_to_idle(struct task_struct *p)
 }
 
 #ifdef CONFIG_SCHED_WALT
+static inline bool is_task_util_above_min_thresh(struct task_struct *p)
+{
+	unsigned int threshold = (sysctl_sched_boost == CONSERVATIVE_BOOST) ?
+			sysctl_sched_min_task_util_for_boost :
+			sysctl_sched_min_task_util_for_colocation;
+
+	return task_util(p) > threshold;
+}
+
 static inline struct cpumask *find_rtg_target(struct task_struct *p)
 {
 	struct related_thread_group *grp;
@@ -7961,9 +7972,7 @@ static inline struct cpumask *find_rtg_target(struct task_struct *p)
 	rcu_read_lock();
 
 	grp = task_related_thread_group(p);
-	if (grp && grp->preferred_cluster &&
-			(task_util(p) >
-			sysctl_sched_min_task_util_for_boost_colocation)) {
+	if (grp && grp->preferred_cluster && is_task_util_above_min_thresh(p)) {
 		rtg_target = &grp->preferred_cluster->cpus;
 		if (!task_fits_max(p, cpumask_first(rtg_target)))
 			rtg_target = NULL;

kernel/sched/sched.h

@@ -2940,7 +2940,7 @@ static inline enum sched_boost_policy task_boost_policy(struct task_struct *p)
 		 */
 		if (sysctl_sched_boost == CONSERVATIVE_BOOST &&
 				task_util(p) <=
-				sysctl_sched_min_task_util_for_boost_colocation)
+				sysctl_sched_min_task_util_for_boost)
 			policy = SCHED_BOOST_NONE;
 	}
 

kernel/sysctl.c

@@ -378,8 +378,17 @@ static struct ctl_table kern_table[] = {
 		.extra2		= &one,
 	},
 	{
-		.procname	= "sched_min_task_util_for_boost_colocation",
-		.data		= &sysctl_sched_min_task_util_for_boost_colocation,
+		.procname	= "sched_min_task_util_for_boost",
+		.data		= &sysctl_sched_min_task_util_for_boost,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &one_thousand,
+	},
+	{
+		.procname	= "sched_min_task_util_for_colocation",
+		.data		= &sysctl_sched_min_task_util_for_colocation,
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_minmax,