title: at what percentage of old generation GC runs?
body: <p>when I run "jmap -heap ", i get the following</p>
  
  <p><a href="https://i.stack.imgur.com/BpbBB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BpbBB.png" alt="enter image description here"></a></p>
  
  <p>If you notice, PS Old Generation is just a little over 9% used while Eden is ~4.5% used. 
  At what percentage of Eden does minor GC occur? 
  At what percentage of PS Old generation does the stop the world GC occurs?</p>