start_kernel -> setup_nr_cpu_ids & smp_prepare_boot_cpu 848asmlinkage __visiblevoid__init __no_sanitize_address start_kernel(void)849{873setup_nr_cpu_ids();874setup_per_cpu_areas();875smp_prepare_boot_cpu();/*arch-specific boot-cpu hooks*/876boot_cpu_hotplug_init();877 873 - 设置...