Proposed fix for coresched migration issue with CFS shares

coresched.patch

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f42ceecb749f..215c6d546947 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1767,6 +1767,8 @@ static void task_numa_compare(struct task_numa_env *env,
 	rcu_read_unlock();
 }
 
+static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p);
+
 static void task_numa_find_cpu(struct task_numa_env *env,
 				long taskimp, long groupimp)
 {
@@ -5650,6 +5652,39 @@ static struct sched_group *
 find_idlest_group(struct sched_domain *sd, struct task_struct *p,
 		  int this_cpu, int sd_flag);
 
+#ifdef CONFIG_SCHED_CORE
+static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
+{
+	bool idle_core = true;
+	int cpu;
+
+	/* Ignore cookie match if core scheduler is not enabled on the CPU. */
+	if (!sched_core_enabled(rq))
+		return true;
+
+	if (rq->core->core_forceidle)
+		return true;
+
+	if (task_h_load(p) > task_h_load(rq->curr))
+		return true;
+	if (task_util_est(p) > task_util_est(rq->curr))
+		return true;
+
+	for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) {
+		if (!available_idle_cpu(cpu)) {
+			idle_core = false;
+			break;
+		}
+	}
+
+	/*
+	 * A CPU in an idle core is always the best choice for tasks with
+	 * cookies.
+	 */
+	return idle_core || rq->core->core_cookie == p->core_cookie;
+}
+#endif
+
 /*
  * find_idlest_group_cpu - find the idlest CPU among the CPUs in the group.
  */
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 262442c13e99..8c607e9e2bb5 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1061,29 +1061,6 @@ static inline raw_spinlock_t *rq_lockp(struct rq *rq)
 	return &rq->__lock;
 }
 
-static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
-{
-	bool idle_core = true;
-	int cpu;
-
-	/* Ignore cookie match if core scheduler is not enabled on the CPU. */
-	if (!sched_core_enabled(rq))
-		return true;
-
-	for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) {
-		if (!available_idle_cpu(cpu)) {
-			idle_core = false;
-			break;
-		}
-	}
-
-	/*
-	 * A CPU in an idle core is always the best choice for tasks with
-	 * cookies.
-	 */
-	return idle_core || rq->core->core_cookie == p->core_cookie;
-}
-
 extern void queue_core_balance(struct rq *rq);
 
 void sched_core_add(struct rq *rq, struct task_struct *p);