Clock-based Profiling for MPI Programs

When clock-profiling data is collected on an MPI experiment run with a version of Sun HPC ClusterTools that has functionality for MPI State profiling, two additional metrics can be shown:

• MPI Work, which accumulates when the process is inside the MPI runtime doing work, such as processing requests or messages

• MPI Wait, which accumulates when the process is inside the MPI runtime, but waiting for an event, buffer, or message

On the Linux OS, MPI Work and MPI Wait are accumulated only when the process is active in either user or system mode. Unless you have specified that MPI should do a busy wait, MPI Wait on Linux is not useful.