If the tracepoint has to be used in kernel modules, an
EXPORT_TRACEPOINT_SYMBOL_GPL() or EXPORT_TRACEPOINT_SYMBOL() can be
used to export the defined tracepoints.
+
+Note: The convenience macro TRACE_EVENT provides an alternative way to
+ define tracepoints. Check http://lwn.net/Articles/379903,
+ http://lwn.net/Articles/381064 and http://lwn.net/Articles/383362
+ for a series of articles with more details.