title: monitor memory usage with R parallel
body: <p>Is there a way to monitor <em>true</em> memory usage when using R parallel, particularly with SOCK-type clusters? </p>
  
  <p>I tried with <code>profvis</code> but it returns a smaller memory footprint with a parallel analogue of the serial statement. For instance, </p>
  
  <pre><code>lapply(...)
  parLapply(...)
  </code></pre>
  
  <p>where <code>(...)</code> is the same statement.</p>
  
  <p>As far as I understand, memory usage should be equal-to or larger with a parallel statement because data needs to be copied (at least for SOCK clusters). Any feedback is appreciated.</p>