TotalView Online Help : Chapter 2 Process Window : Group Menu Commands : Group > Step
Group > Step
Steps all processes in the control group that are in the same lockstep group as the thread of interest. That is, TotalView lets these lockstep threads execute one source line. If the current line contains a function call, TotalView steps into this function.
TotalView examines the control group to identify which processes have a thread stopped at the same location as the thread of interest. This thread is called the matching thread. After selecting a matching thread from each matching process, TotalView allows all processes in all control groups to run freely. It then waits until the thread of interest and each matching thread arrive at the next source statement.
 
NOTE >> If more than one statement exists on the line, all are executed.
Contrast this command with the process and thread versions:
The process version steps all threads in the process of interest.
The threads version only steps the current thread; the other threads in the process remain stopped during the step.
For more information on processes and threads and their behavior while being stepped, see Group, Process, and Thread Control” in the “TotalView Users Guide”.