TotalView Online Help : Chapter 2 Process Window : Process Menu Commands : Process > Step
Process > Step
Steps all threads in the lockstep group associated with the thread of interest that are within the process. That is, TotalView lets these lockstep threads execute one source line. If the current line contains a function call, TotalView steps into it.
 
NOTE >> If more than one statement exists on the line, all are executed.
If the process exists, TotalView runs the selected thread until the PC reaches the next address for which it has source line information. If the process does not yet exist, this command launches the process and runs the first thread until the PC reaches the first address for which TotalView has source line information.
While the lockstep group is being run to the next source line, the entire process is also allowed to run. The operation does not complete until all the threads in the lockstep group thread finish stepping, or another thread hits a breakpoint.
For more information on processes and threads and their behavior while being stepped, see Group, Process, and Thread Control” in the “TotalView Users Guide”.