title: jmap -F(force) option doesn't work
body: <p>I was diagnosing a JVM problem with <code>jmap</code> command:</p>
  
  <pre><code>jmap -histo:live &lt;pid&gt;
  </code></pre>
  
  <p>and got the following prompt:</p>
  
  <pre><code>&lt;pid&gt;: Unable to open socket file: target process not responding or HotSpot VM not loaded
  The -F option can be used when the target process is not responding
  </code></pre>
  
  <p>Then I issued <code>jmap</code> again with <code>-F</code> option:</p>
  
  <pre><code>jmap -F -histo:live &lt;pid&gt;
  </code></pre>
  
  <p>and got the <code>jmap</code> usage prompt. It seems that I typed wrong command options. Why did this happen?</p>