sched/fair: Move init_numa_balancing() below task_numa_work()

To reference task_numa_work() from within init_numa_balancing(), we
need the former to be declared before the latter. Do just that.

This is a pure code movement.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mgorman@suse.de
Cc: riel@surriel.com
Link: https://lkml.kernel.org/r/20190715102508.32434-2-valentin.schneider@arm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -1188,47 +1188,6 @@ static unsigned int task_scan_max(struct task_struct *p)
 	return max(smin, smax);
 }
 
-void init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
-{
-	int mm_users = 0;
-	struct mm_struct *mm = p->mm;
-
-	if (mm) {
-		mm_users = atomic_read(&mm->mm_users);
-		if (mm_users == 1) {
-			mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
-			mm->numa_scan_seq = 0;
-		}
-	}
-	p->node_stamp			= 0;
-	p->numa_scan_seq		= mm ? mm->numa_scan_seq : 0;
-	p->numa_scan_period		= sysctl_numa_balancing_scan_delay;
-	p->numa_work.next		= &p->numa_work;
-	p->numa_faults			= NULL;
-	RCU_INIT_POINTER(p->numa_group, NULL);
-	p->last_task_numa_placement	= 0;
-	p->last_sum_exec_runtime	= 0;
-
-	/* New address space, reset the preferred nid */
-	if (!(clone_flags & CLONE_VM)) {
-		p->numa_preferred_nid = NUMA_NO_NODE;
-		return;
-	}
-
-	/*
-	 * New thread, keep existing numa_preferred_nid which should be copied
-	 * already by arch_dup_task_struct but stagger when scans start.
-	 */
-	if (mm) {
-		unsigned int delay;
-
-		delay = min_t(unsigned int, task_scan_max(current),
-			current->numa_scan_period * mm_users * NSEC_PER_MSEC);
-		delay += 2 * TICK_NSEC;
-		p->node_stamp = delay;
-	}
-}
-
 static void account_numa_enqueue(struct rq *rq, struct task_struct *p)
 {
 	rq->nr_numa_running += (p->numa_preferred_nid != NUMA_NO_NODE);
@@ -2665,6 +2624,47 @@ void task_numa_work(struct callback_head *work)
 	}
 }
 
+void init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
+{
+	int mm_users = 0;
+	struct mm_struct *mm = p->mm;
+
+	if (mm) {
+		mm_users = atomic_read(&mm->mm_users);
+		if (mm_users == 1) {
+			mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
+			mm->numa_scan_seq = 0;
+		}
+	}
+	p->node_stamp			= 0;
+	p->numa_scan_seq		= mm ? mm->numa_scan_seq : 0;
+	p->numa_scan_period		= sysctl_numa_balancing_scan_delay;
+	p->numa_work.next		= &p->numa_work;
+	p->numa_faults			= NULL;
+	RCU_INIT_POINTER(p->numa_group, NULL);
+	p->last_task_numa_placement	= 0;
+	p->last_sum_exec_runtime	= 0;
+
+	/* New address space, reset the preferred nid */
+	if (!(clone_flags & CLONE_VM)) {
+		p->numa_preferred_nid = NUMA_NO_NODE;
+		return;
+	}
+
+	/*
+	 * New thread, keep existing numa_preferred_nid which should be copied
+	 * already by arch_dup_task_struct but stagger when scans start.
+	 */
+	if (mm) {
+		unsigned int delay;
+
+		delay = min_t(unsigned int, task_scan_max(current),
+			current->numa_scan_period * mm_users * NSEC_PER_MSEC);
+		delay += 2 * TICK_NSEC;
+		p->node_stamp = delay;
+	}
+}
+
 /*
  * Drive the periodic memory faults..
  */