title: How to enable dynamic debugging in the Linux kernel?
body: <p>I have enabled the <code>CONFIG_DYNAMIC_DEBUG</code> flag in kernel config file. when I boot in my system I am able to mount the<code>/sys/kernel/debug</code> and there is <code>dynamic_debug/control</code> file too.</p>
  
  <p>But when I issue any command like</p>
  
  <pre><code>echo -n 'module nfsd +p' &gt; &lt;debugfs&gt;/dynamic_debug/control
  </code></pre>
  
  <p>it does not shows any output in <code>dmesg</code> OR <code>syslogd</code>. What am I doing wrong?</p>