開關cpu 指令

Disable a CPU core on Ubuntu
1. cat /proc/cpuinfo
2. echo 0 | sudo tee /sys/devices/system/cpu/cpu1/online
    關CPU1

3. echo 1 | sudo tee /sys/devices/system/cpu/cpu1/online
    開CPU1

[Reference]
http://www.upubuntu.com/2011/09/how-to-disable-cpu-core-on-ubuntudebian.html