diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e9abd4e4c5cb..34baa60f8a7b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -828,11 +828,12 @@ static unsigned int task_nr_scan_windows(struct task_struct *p)
 
 static unsigned int task_scan_min(struct task_struct *p)
 {
+	unsigned int scan_size = ACCESS_ONCE(sysctl_numa_balancing_scan_size);
 	unsigned int scan, floor;
 	unsigned int windows = 1;
 
-	if (sysctl_numa_balancing_scan_size < MAX_SCAN_WINDOW)
-		windows = MAX_SCAN_WINDOW / sysctl_numa_balancing_scan_size;
+	if (scan_size < MAX_SCAN_WINDOW)
+		windows = MAX_SCAN_WINDOW / scan_size;
 	floor = 1000 / windows;
 
 	scan = sysctl_numa_balancing_scan_period_min / task_nr_scan_windows(p);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 4aada6d9fe74..15f2511a1b7c 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -387,7 +387,8 @@ static struct ctl_table kern_table[] = {
 		.data		= &sysctl_numa_balancing_scan_size,
 		.maxlen		= sizeof(unsigned int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &one,
 	},
 	{
 		.procname	= "numa_balancing",