Progress Towards EXascale ApplicaTions (TEXT)
Even the most successful superstars eventually fade from the scene. Parallel programming models are no exception (yes, I’m talking about you, MPI). Researchers in several EU centers are on a search for a fresh “star” model that might appeal to the next generation of HPC developers — Gen Ex(ascale). A collaborative team of researchers in Greece, Germany, France, Spain, Switzerland, and the UK think they may have found an attractive candidate in the StarSs programming model. They will undertake a series of pragmatic tests, using petascale machines in various HPC centers across the EU and a challenging group of real-world applications, to determine if the MPI + StarSs model (implemented as MPI/SMPSs) shows promise in supporting application development for exascale environments. The project, called TEXT — Towards EXascale ApplicaTions, is part of the EU’s competitive focus on taking a leadership role in exascale software development.
Ask the HPC community about the challenges in moving to an exascale-capable programming model and you will be barraged with a formidable list. Any given discussion is likely to include synchronization, portability of mainstream MPI-based codes, programmer accessibility, fault tolerance, reduction of communication, dealing with heterogeneity, and, of course, power management. The TEXT project won’t take them all on, but it will confront a few of the biggest ones. The HPC community is asking “Can the expense of the exascale effort be justified without providing a clear migration path for tried and true workhorse codes?” The MPI/SMPSs programming model is based on some not-so-new raw materials and concepts, but is thought to be one way to provide that portability, while addressing key requirements for increased performance, enhanced asynchrony and support for various possible heterogeneous architectures.