title: How to convert the clock ticks to milliseconds?
body: <p>I want to retrieve the amount of time in milliseconds that a process has spent taking up CPU time since the process was started.</p>
  
  <p>I can found in the <code>/proc/&lt;pid&gt;/stat</code> the fields:</p>
  
  <ul>
  <li><code>#14</code> <code>utime</code> - CPU time spent in user code, measured in <em>clock ticks</em></li>
  <li><code>#15</code> <code>stime</code> - CPU time spent in kernel code, measured in <em>clock ticks</em></li>
  </ul>
  
  <p>I think the time I want is:</p>
  
  <pre><code>mytime = utime + stime
  </code></pre>
  
  <p>Am I right?</p>
  
  <p>And How to convert the <code>utime</code> and <code>stime</code> from clock ticks to milliseconds ?</p>