+#ifdef HAVE_HOTPLUG_STATE_MACHINE
+static enum cpuhp_state lustre_cpu_online;
+
+static int cfs_cpu_online(unsigned int cpu)
+{
+ return 0;
+}
+#endif
+
+static int cfs_cpu_dead(unsigned int cpu)
+{
+ bool warn;
+
+ /* if all HTs in a core are offline, it may break affinity */
+ warn = cpumask_any_and(topology_sibling_cpumask(cpu),
+ cpu_online_mask) >= nr_cpu_ids;
+ CDEBUG(warn ? D_WARNING : D_INFO,
+ "Lustre: can't support CPU plug-out well now, performance and stability could be impacted [CPU %u]\n",
+ cpu);
+ return 0;
+}
+
+#ifndef HAVE_HOTPLUG_STATE_MACHINE