Development of an MPI profiling library on the IBM BlueGene system

The aim of the project is to develop a light-weight MPI profiling library that differentiates between local communication (intra-node or nearby nodes) and distant communication (> 1 hop) within the 3D torus of BlueGene sys-tems. The library should use the standard PMPI profiling interface and be as portable as possible. It involves the instrumentation in C- all the point to point MPI functions (MPI [ISB]Send and MPI [I]Recv) and communica-tor creation (to keep track of the actual MPI ranks). It is also necessary to identify a suitable trace file format, and developing a tool to parse/analyse the trace files with a high-level programming language (e.g. Python). The impact of process placement on torus will be assessed on systems such as BG/L, BG/P and Cray XT4 (Hector, if the library is portable)