if (cpu_hotplug.active_writer == current)
return;
mutex_lock(&cpu_hotplug.lock);
+
+ if (WARN_ON(!cpu_hotplug.refcount))
+ cpu_hotplug.refcount++; /* try to fix things up */
+
if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer))
wake_up_process(cpu_hotplug.active_writer);
mutex_unlock(&cpu_hotplug.lock);