title: Swap related memory problem in Ubuntu
body: <p>When I run a <code>top</code> and get it to show swap usage, I get the following output. However, I have disabled swap with <code>swapoff -a</code> prior to starting firefox. What is shown in the <code>SWAP</code> field here then? 
  When I do <code>cat /proc/meminfo</code>, I get a nonzero value for a field named <code>SwapCached</code>. What is this? My guess it this is the aggregate of all the <code>SWAP</code> values shown in <code>top</code>. How are these related to total memory used by a process? </p>
  
  <pre><code>PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  SWAP 
      COMMAND                                                                                                                                      
           1604 dumrat    20   0  287m  62m  26m R    1  3.1   0:05.03 225m firefox-bin                                                                                                                                  
           1415 dumrat     9 -11 94264 4668 3552 S    0  0.2   0:00.10  87m pulseaudio 
  </code></pre>