--- b/kernel/cpu.c
+++ a/kernel/cpu.c
@@ -1917,15 +1917,6 @@
 	kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
 }
 
-static void cpuhp_online_cpu_device(unsigned int cpu)
-{
-	struct device *dev = get_cpu_device(cpu);
-
-	dev->offline = false;
-	/* Tell user space about the state change */
-	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
-}
-
 static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 {
 	int cpu, ret = 0;
@@ -1958,24 +1949,11 @@
 	return ret;
 }
 
+static void cpuhp_smt_enable(void)
-static int cpuhp_smt_enable(void)
 {
-	int cpu, ret = 0;
-
 	cpu_maps_update_begin();
 	cpu_smt_control = CPU_SMT_ENABLED;
-	for_each_present_cpu(cpu) {
-		/* Skip online CPUs and CPUs on offline nodes */
-		if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
-			continue;
-		ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
-		if (ret)
-			break;
-		/* See comment in cpuhp_smt_disable() */
-		cpuhp_online_cpu_device(cpu);
-	}
 	cpu_maps_update_done();
-	return ret;
 }
 
 static ssize_t
@@ -2006,7 +1984,7 @@
 	if (ctrlval != cpu_smt_control) {
 		switch (ctrlval) {
 		case CPU_SMT_ENABLED:
+			cpuhp_smt_enable();
-			ret = cpuhp_smt_enable();
 			break;
 		case CPU_SMT_DISABLED:
 		case CPU_SMT_FORCE_DISABLED: