CONFIG_ACPI_HOTPLUG_CPU (not configurable)

configname: CONFIG_ACPI_HOTPLUG_CPU

Linux Kernel Configuration
└─>Power management and ACPI options
└─>ACPI (Advanced Configuration and Power Interface) Support
└─>ACPI_HOTPLUG_CPU
In linux kernel since version 4.2 (release Date: 2015-08-30)