title: Erlang "system" memory section keeps growing
body: <p>I have an application with the following pattern:</p>
  
  <ul>
  <li>2 long running processes that go into hibernate after some idle time
  and their memory consumption goes down as expected</li>
  <li>N (0 &lt; N &lt; 100) worker processes that do some work and hibernate when idle more than
  10 seconds or terminate if idle more than two hours</li>
  <li>during the night,
  when there is no activity the process memory goes back to almost the
  same value that was at the application start, which is expected as
  all the workers have died.</li>
  </ul>
  
  <p>The issue is that "system" section keeps growing (around 1GB/week).</p>
  
  <p>My question is how can I debug what is stored there or who's allocating memory in that area and is not freeing it.</p>
  
  <p>I've already tested <b>lists:keysearch/3</b> and it doesn't seem to leak memory, as that is the only native thing I'm using (no ports, no drivers, no NIFs, no BIFs, nothing). Erlang version is R15B03.</p>
  
  <p>Here is the current <b>erlang:memory()</b> output (slight traffic, app started on Feb 03):</p>
  
  <pre><code>[{total,378865650},
  {processes,100727351},
  {processes_used,100489511},
  {system,278138299},
  {atom,1123505},
  {atom_used,1106100},
  {binary,4493504},
  {code,7960564},
  {ets,489944},
  {maximum,402598426}]
  </code></pre>
  
  <p>This is a 64-bit system. As you can see, "system" section has ~270MB and "processes" is at around 100MB (that drops down to ~16MB during the night).</p>