CPU hotplugging

http://en.kioskea.net/faq/616-multicore-cpu-how-to-disable-a-core

During boot,

add maxcpus=X in the kernel command line

Without reboot,
(From http://www.cyberciti.biz/faq/debian-rhel-centos-redhat-suse-hotplug-cpu/)

# cd /sys/devices/system/cpu
# ls -l

# echo 0 > /sys/devices/system/cpu/cpu6/online
# grep “processor” /proc/cpuinfo

# echo 1 > /sys/devices/system/cpu/cpu6/online
# grep “processor” /proc/cpuinfo