title: android how to force cpu core offline(shut down cores)
body: <p>I'm using a <strong>quad-core</strong> smartphone.</p>
  
  <p>I want to know how to force three cores or two cores <strong>offline</strong>. Thus I can measure the performance of different active core counts at different frequency level running a specified benchmark.</p>
  
  <p>I can manage the core frequency through "<em>userspace governor</em>". However, I can't shut down cores. When I run benchmarks, the idle cores will wake up.</p>
  
  <p>I've connect to the phone using "<em>adb shell</em>". I can get the root access either. </p>
  
  <p>Could anyone help to solve this problem? Thanks in advance.</p>