Extra-P is an automatic performance modeling tool that supports the user in the identification of performance bugs. A performance bug is a part of the program whose behavior is unintentionally poor, that is, much worse than expected, with respect to an increase in processor count. Extra-P uses measurements of different performance metrics as an input to define the performance of code regions as a function of the number of processes (or another parameter). All it takes to search for scalability issues even in full-blown codes is to run a manageable number of small-scale performance experiments, launch Extra-P, and compare the extrapolated performance of the worst instances to expectations.
Extra-P generates not only a list of potential bugs but human-readable models for all performance metrics available such as floating point operations count or bytes sent by MPI calls that can be further analyzed and compared to identify the root causes of performance issues.
MPI and OpenMP
Open source: New BSD
TU Darmstadt, Lawrence Livermore National Laboratory, and Forschungszentrum Jülich