Default View
By default, the Root Window displays Control Group, Process State, Function and Thread ID in a hierarchical or "nested" manner.
Figure 64 shows a 32-process, 32-thread MPI job, each process containing one thread, which is a single-threaded MPI starter process (e.g., mpiexec).
 
Figure 64 – Root Window: Default View
Since there is only one control group in the debug session, the control group has been omitted, and the Process state becomes the top-level property, in this case displaying two process states:
The first grouping lists the MPI starter process in Breakpoint process state, stopped in function MPIR_Breakpoint, and one thread with thread ID 1.1. The Procs column shows the number of processes, and the Threads column shows the number of threads displayed in the Members column. The Members column shows the dpid the process and dpid.dtid of the threads, displayed as a compressed process/thread list ptlist.
The grouping defined by "Stopped" displays all processes in a Stopped process state, of which there are 32, the MPI job size. The membership shows 0-31, which means MPI ranks 0 to 31, inclusive.