The circle of observability

Source: http://www.youtube.com/watch?v=l7aQWoTRqKw

   +----->  PROFILING -----+       
   |         -top          |
   |         -oprofile     |
   |         -perf         |
   |                       |
   |     +---------+       |
   |     |SystemTap|       |
   |     +---------+       |
   |                       |
   |                       v
 DEBUGGING <------------- TRACING
  -gdb                    -strace
                          -ltrace
                          -ftrace