From 50df5832acea15cbc768e5ee502e4af45c6663c7 Mon Sep 17 00:00:00 2001
From: Daeyeong Lee <daeyeong.lee@samsung.com>
Date: Tue, 27 Mar 2018 18:46:50 +0900
Subject: [PATCH] [COMMON] sched: ems: New function to check whether task make
 cpu overutilize

The lbt_bring_overutilize function checks whether the CPU will be overutilized
at all levels when a task is added to the CPU.

Change-Id: Idbeb0f06f65ab7a807d85f4e76fc1fb8931d12f7
Signed-off-by: Daeyeong Lee <daeyeong.lee@samsung.com>
---
 kernel/sched/ems/ems.h |  1 +
 kernel/sched/ems/lbt.c | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/kernel/sched/ems/ems.h b/kernel/sched/ems/ems.h
index a3cf41e19253..9cf27e760746 100644
--- a/kernel/sched/ems/ems.h
+++ b/kernel/sched/ems/ems.h
@@ -19,6 +19,7 @@ extern struct kobject *ems_kobj;
 
 extern int ontime_task_wakeup(struct task_struct *p);
 extern int global_boosting(struct task_struct *p);
+extern bool lbt_bring_overutilize(int cpu, struct task_struct *p);
 
 #ifdef CONFIG_SCHED_TUNE
 extern int prefer_perf_cpu(struct task_struct *p);
diff --git a/kernel/sched/ems/lbt.c b/kernel/sched/ems/lbt.c
index 359f51794e21..a2f65f0c1afc 100644
--- a/kernel/sched/ems/lbt.c
+++ b/kernel/sched/ems/lbt.c
@@ -67,6 +67,30 @@ static inline int get_last_level(struct lbt_overutil *ou)
 	return -1;
 }
 
+static inline unsigned long task_util(struct task_struct *p)
+{
+	return p->se.avg.util_avg;
+}
+
+static inline int check_migration_task(struct task_struct *p)
+{
+	return !p->se.avg.last_update_time;
+}
+
+static inline unsigned long cpu_util_wake(int cpu, struct task_struct *p)
+{
+	unsigned long util, capacity;
+
+	/* Task has no contribution or is new */
+	if (cpu != task_cpu(p) || check_migration_task(p))
+		return cpu_util(cpu);
+
+	capacity = capacity_orig_of(cpu);
+	util = max_t(long, cpu_util(cpu) - task_util(p), 0);
+
+	return (util >= capacity) ? capacity : util;
+}
+
 /****************************************************************/
 /*			External APIs				*/
 /****************************************************************/
@@ -87,6 +111,23 @@ bool lbt_overutilized(int cpu, int level)
 	return overutilized;
 }
 
+bool lbt_bring_overutilize(int cpu, struct task_struct *p)
+{
+	struct sched_domain *sd;
+	struct lbt_overutil *ou = per_cpu(lbt_overutil, cpu);
+	unsigned long util_sum = cpu_util_wake(cpu, p) + task_util(p);
+
+	if (!ou)
+		return false;
+
+	for_each_domain(cpu, sd) {
+		if (util_sum > ou[sd->level].capacity)
+			return true;
+	}
+
+	return false;
+}
+
 void update_lbt_overutil(int cpu, unsigned long capacity)
 {
 	struct lbt_overutil *ou = per_cpu(lbt_overutil, cpu);
-- 
2.20.1