title: where does top gets real-time data
body: <p>Where does <code>top</code> application gets it's data on Linux? I would be interested in real-time CPU load/pid data.(I read allmost all documentation in /proc/pid man page, but the info isn't there).</p>
  
  <p>The pid is a jboss. I need the data lightweight (to be exported easily).</p>