When examining a process (say, single-threaded) and the process forks, the
process trace produces an event but the thread trace does not. Since there is
only one thread in the process, these events should show up on that thread trace.
If there are multiple threads, then the event should show up on the relevant
trace as well as the process trace, which combines events from all threads.
Created attachment 1440 [details]
Screenshot of frysk with actions per thread.