Enable CPU hotplug state control


Linux Kernel Configuration
└─>Kernel hacking
└─>Enable CPU hotplug state control
In linux kernel since version 4.1 (release Date: 2015-06-21)  
Allows to write steps between "offline" and "online" to the CPUs
sysfs target file so states can be stepped granular. This is a debug
option for now as the hotplug machinery cannot be stopped and
restarted at arbitrary points yet.

Say N if your are unsure.