title: what is the command line argument for running process in multiple cores (linux)
body: <p>I am trying to run my program in more than one core. I have 12 cores in my desktop and want the computer to use  1,2,3,4,......,11,12 one by one and want to test how the program performs in different number of cores. I tried using -t4 or -t 4 after the executable like.</p>
  
  <pre><code>./a.out -t4 
  </code></pre>
  
  <p>but I cannot make sure whether its using exactly 4 or not. Can anyone please help me out understand this or point me in right direction.  </p>