title: What's the difference between tms_utime and tms_stime with the times() function?
body: <p>What's the difference between <code>tms_utime</code> and <code>tms_stime</code> exactly? I'm referring to the <code>struct tms</code> used by the POSIX <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/times.html" rel="nofollow"><code>times()</code></a>
   function.  Is the data caching time included in the <code>utime</code>? Can the data caching time be measured separately?</p>
  
  <p>PS: I am using Linux-Ubuntu. For example, I am solving a large sparse linear equation system using my C++ program.</p>