CPU_DYING is notified in atomic context, so no taking mutexes here.
Signed-off-by: Avi Kivity <avi@qumranet.com>
        int err;
 
        sys_dev = get_cpu_sysdev(cpu);
-       mutex_lock(&therm_cpu_lock);
        switch (action) {
        case CPU_ONLINE:
        case CPU_ONLINE_FROZEN:
+               mutex_lock(&therm_cpu_lock);
                err = thermal_throttle_add_dev(sys_dev);
+               mutex_unlock(&therm_cpu_lock);
                WARN_ON(err);
                break;
        case CPU_DEAD:
        case CPU_DEAD_FROZEN:
+               mutex_lock(&therm_cpu_lock);
                thermal_throttle_remove_dev(sys_dev);
+               mutex_unlock(&therm_cpu_lock);
                break;
        }
-       mutex_unlock(&therm_cpu_lock);
        return NOTIFY_OK;
 }