title: How to disable cpu cores in Linux 3.4 kernel?
body: <p>I have a question about how to disable cpu cores in my linux-3.4 version. I typed "echo 0 > /sys/devices/system/cpu/cpu0/online" on the shell to only activate cpu1 except for cpu0 (because there are dual cores in my cortex-A20 board) but there are no existing directory in my linux...</p>
  
  <p>So I went to the directory in my linux such as capture posted:</p>
  
  <p><a href="https://i.stack.imgur.com/P9K3A.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/P9K3A.png" alt="enter image description here"></a></p>
  
  <p>and don't know how to disable cpu cores..</p>
  
  <p>are there any way to disable cpu0 before building kernel image or running </p>
  
  <p>linux 3-4 after porting kernel image to sdcard? </p>