[RFC PATCH 3/4] sched: Move cpu load stats functions above fair queue callbacks

[Frederic Weisbecker]

We are going to update nohz full CPU load from fair queue update
functions. Lets make these cpu load functions visible from the queue
callbacks.

Cc: Byungchul Park <byungchul.park@xxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Cc: Paul E . McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
 kernel/sched/fair.c | 216 ++++++++++++++++++++++++++--------------------------
 1 file changed, 109 insertions(+), 107 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 161cee2..1e0cb6e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4199,113 +4199,6 @@ static inline void hrtick_update(struct rq *rq)
 }
 #endif
 
-/*
- * The enqueue_task method is called before nr_running is
- * increased. Here we update the fair scheduling stats and
- * then put the task into the rbtree:
- */
-static void
-enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
-{
-	struct cfs_rq *cfs_rq;
-	struct sched_entity *se = &p->se;
-
-	for_each_sched_entity(se) {
-		if (se->on_rq)
-			break;
-		cfs_rq = cfs_rq_of(se);
-		enqueue_entity(cfs_rq, se, flags);
-
-		/*
-		 * end evaluation on encountering a throttled cfs_rq
-		 *
-		 * note: in the case of encountering a throttled cfs_rq we will
-		 * post the final h_nr_running increment below.
-		*/
-		if (cfs_rq_throttled(cfs_rq))
-			break;
-		cfs_rq->h_nr_running++;
-
-		flags = ENQUEUE_WAKEUP;
-	}
-
-	for_each_sched_entity(se) {
-		cfs_rq = cfs_rq_of(se);
-		cfs_rq->h_nr_running++;
-
-		if (cfs_rq_throttled(cfs_rq))
-			break;
-
-		update_load_avg(se, 1);
-		update_cfs_shares(cfs_rq);
-	}
-
-	if (!se)
-		add_nr_running(rq, 1);
-
-	hrtick_update(rq);
-}
-
-static void set_next_buddy(struct sched_entity *se);
-
-/*
- * The dequeue_task method is called before nr_running is
- * decreased. We remove the task from the rbtree and
- * update the fair scheduling stats:
- */
-static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
-{
-	struct cfs_rq *cfs_rq;
-	struct sched_entity *se = &p->se;
-	int task_sleep = flags & DEQUEUE_SLEEP;
-
-	for_each_sched_entity(se) {
-		cfs_rq = cfs_rq_of(se);
-		dequeue_entity(cfs_rq, se, flags);
-
-		/*
-		 * end evaluation on encountering a throttled cfs_rq
-		 *
-		 * note: in the case of encountering a throttled cfs_rq we will
-		 * post the final h_nr_running decrement below.
-		*/
-		if (cfs_rq_throttled(cfs_rq))
-			break;
-		cfs_rq->h_nr_running--;
-
-		/* Don't dequeue parent if it has other entities besides us */
-		if (cfs_rq->load.weight) {
-			/*
-			 * Bias pick_next to pick a task from this cfs_rq, as
-			 * p is sleeping when it is within its sched_slice.
-			 */
-			if (task_sleep && parent_entity(se))
-				set_next_buddy(parent_entity(se));
-
-			/* avoid re-evaluating load for this entity */
-			se = parent_entity(se);
-			break;
-		}
-		flags |= DEQUEUE_SLEEP;
-	}
-
-	for_each_sched_entity(se) {
-		cfs_rq = cfs_rq_of(se);
-		cfs_rq->h_nr_running--;
-
-		if (cfs_rq_throttled(cfs_rq))
-			break;
-
-		update_load_avg(se, 1);
-		update_cfs_shares(cfs_rq);
-	}
-
-	if (!se)
-		sub_nr_running(rq, 1);
-
-	hrtick_update(rq);
-}
-
 #ifdef CONFIG_SMP
 
 /*
@@ -4537,8 +4430,117 @@ void update_cpu_load_active(struct rq *this_rq)
 	this_rq->last_load_update_tick = jiffies;
 	__update_cpu_load(this_rq, load, 1, 1);
 }
+#endif /* CONFIG_SMP */
 
 /*
+ * The enqueue_task method is called before nr_running is
+ * increased. Here we update the fair scheduling stats and
+ * then put the task into the rbtree:
+ */
+static void
+enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
+{
+	struct cfs_rq *cfs_rq;
+	struct sched_entity *se = &p->se;
+
+	for_each_sched_entity(se) {
+		if (se->on_rq)
+			break;
+		cfs_rq = cfs_rq_of(se);
+		enqueue_entity(cfs_rq, se, flags);
+
+		/*
+		 * end evaluation on encountering a throttled cfs_rq
+		 *
+		 * note: in the case of encountering a throttled cfs_rq we will
+		 * post the final h_nr_running increment below.
+		*/
+		if (cfs_rq_throttled(cfs_rq))
+			break;
+		cfs_rq->h_nr_running++;
+
+		flags = ENQUEUE_WAKEUP;
+	}
+
+	for_each_sched_entity(se) {
+		cfs_rq = cfs_rq_of(se);
+		cfs_rq->h_nr_running++;
+
+		if (cfs_rq_throttled(cfs_rq))
+			break;
+
+		update_load_avg(se, 1);
+		update_cfs_shares(cfs_rq);
+	}
+
+	if (!se)
+		add_nr_running(rq, 1);
+
+	hrtick_update(rq);
+}
+
+static void set_next_buddy(struct sched_entity *se);
+
+/*
+ * The dequeue_task method is called before nr_running is
+ * decreased. We remove the task from the rbtree and
+ * update the fair scheduling stats:
+ */
+static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
+{
+	struct cfs_rq *cfs_rq;
+	struct sched_entity *se = &p->se;
+	int task_sleep = flags & DEQUEUE_SLEEP;
+
+	for_each_sched_entity(se) {
+		cfs_rq = cfs_rq_of(se);
+		dequeue_entity(cfs_rq, se, flags);
+
+		/*
+		 * end evaluation on encountering a throttled cfs_rq
+		 *
+		 * note: in the case of encountering a throttled cfs_rq we will
+		 * post the final h_nr_running decrement below.
+		*/
+		if (cfs_rq_throttled(cfs_rq))
+			break;
+		cfs_rq->h_nr_running--;
+
+		/* Don't dequeue parent if it has other entities besides us */
+		if (cfs_rq->load.weight) {
+			/*
+			 * Bias pick_next to pick a task from this cfs_rq, as
+			 * p is sleeping when it is within its sched_slice.
+			 */
+			if (task_sleep && parent_entity(se))
+				set_next_buddy(parent_entity(se));
+
+			/* avoid re-evaluating load for this entity */
+			se = parent_entity(se);
+			break;
+		}
+		flags |= DEQUEUE_SLEEP;
+	}
+
+	for_each_sched_entity(se) {
+		cfs_rq = cfs_rq_of(se);
+		cfs_rq->h_nr_running--;
+
+		if (cfs_rq_throttled(cfs_rq))
+			break;
+
+		update_load_avg(se, 1);
+		update_cfs_shares(cfs_rq);
+	}
+
+	if (!se)
+		sub_nr_running(rq, 1);
+
+	hrtick_update(rq);
+}
+
+#ifdef CONFIG_SMP
+/*
  * Return a low guess at the load of a migration-source cpu weighted
  * according to the scheduling class and "nice" value.
  *
-- 
2.6.4