title: how to reduce spring boot memory usage?
body: <p>I'm using spring boot to develop a client application.
  and when run the spring boot application(using a fully executable jar), the memory usage is about 190M in x64 server, and 110M in x86 server.</p>
  <p>My JVM options are (-Xmx64M -Xms64M -XX:MaxPermSize=64M -server),
  why is it that in the x64 server, memory usage is so big?
  how to reduce memory usage below 150M?</p>
  <p>thanks.</p>