title: Descriptions of lttng kernel events
body: <p>I have just started to explore using LTTng to diagnose a network performance problem and it looks like a great tool to use for this.  I know I can get a list of events I can capture with <strong>lttng list -k</strong> but I can't find any documentation on what the events mean.</p>
  
  <p>For example since I am interested in networking performance of an application it looks like I am interested in the events: </p>
  
  <pre><code>  net_dev_xmit (loglevel: TRACE_EMERG (0)) (type: tracepoint)
    net_dev_queue (loglevel: TRACE_EMERG (0)) (type: tracepoint)
    netif_receive_skb (loglevel: TRACE_EMERG (0)) (type: tracepoint)
    netif_rx (loglevel: TRACE_EMERG (0)) (type: tracepoint)
  </code></pre>
  
  <p>I can pretty much intuit what the difference between <strong>net_dev_xmit</strong> and <strong>net_dev_queue</strong> is, but what does <strong>netif_recieve_skb</strong> mean?  </p>
  
  <p>This is with Ubuntu 12.04 LTS.  </p>
  
  <p>If it turns out that the documentation is just the kernel source code then so be it -- but I didn't want to dig into that if a reference for this was somewhere around and i missed it.   </p>