title: Use all cores to make OpenCV 3
body: <p>How can I force the ubuntu 16.04 to use all the cores to compile or make opencv 3?</p>
  
  <p>I have found a website to change a cmake file called OpenCVFindLibsPerf.cmake, on this blog <a href="https://iamsrijon.wordpress.com/2013/11/15/how-to-compile-opencv-to-utilize-multiple-core-processor-in-linux/" rel="nofollow noreferrer">https://iamsrijon.wordpress.com/2013/11/15/how-to-compile-opencv-to-utilize-multiple-core-processor-in-linux/</a></p>
  
  <p>But it did not work! Maybe because I have already TBB</p>
  
  <p>Any idea?</p>
  
  <p>thanks</p>