CPUID_MAJOR
dev = device_create(&cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL,
device_destroy(&cpuid_class, MKDEV(CPUID_MAJOR, cpu));
if (__register_chrdev(CPUID_MAJOR, 0, NR_CPUS,
CPUID_MAJOR);
__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");
__unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid");