Android - Hotplug Off (Multi-Core enable)

If your device has root permission

adb shell stop mpdecision

adb shell "echo 1 > /sys/devices/system/cpu/cpu1/online"

or

# stop mpdecision

# echo 1 > /sys/devices/system/cpu/cpu1/online

# ...

xda - developers

http://forum.xda-developers.com/showthread.php?t=1216197

update 1/31

Support for hot-pluggable CPUs

CONFIG_HOTPLUG_CPU=y

or # CONFIG_HOTPLUG_CPU is not set

http://cateee.net/lkddb/web-lkddb/HOTPLUG_CPU.html