diff --git a/kernel/cpu.c b/kernel/cpu.c
index cfb1d43..a1ac7ea 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -64,6 +64,8 @@
 	cpu_hotplug.refcount = 0;
 }
 
+cpumask_t cpu_active_map;
+
 #ifdef CONFIG_HOTPLUG_CPU
 
 void get_online_cpus(void)
@@ -291,11 +293,20 @@
 	int err = 0;
 
 	cpu_maps_update_begin();
-	if (cpu_hotplug_disabled)
-		err = -EBUSY;
-	else
-		err = _cpu_down(cpu, 0);
 
+	if (cpu_hotplug_disabled) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	cpu_clear(cpu, cpu_active_map);
+
+	err = _cpu_down(cpu, 0);
+
+	if (cpu_online(cpu))
+		cpu_set(cpu, cpu_active_map);
+
+out:
 	cpu_maps_update_done();
 	return err;
 }
@@ -355,11 +366,18 @@
 	}
 
 	cpu_maps_update_begin();
-	if (cpu_hotplug_disabled)
-		err = -EBUSY;
-	else
-		err = _cpu_up(cpu, 0);
 
+	if (cpu_hotplug_disabled) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	err = _cpu_up(cpu, 0);
+
+	if (cpu_online(cpu))
+		cpu_set(cpu, cpu_active_map);
+
+out:
 	cpu_maps_update_done();
 	return err;
 }