Multi-SPMD Programming Model with YML and XcalableMP

This chapter describes a multi-SPMD (mSPMD) programming model and a set of software and libraries to support the mSPMD programming model. The mSPMD programming model has been proposed to realize scalable applications on huge and hierarchical systems. It has been evident that simple SPMD programs such as MPI, XMP, or hybrid programs such as OpenMP/MPI cannot exploit the postpeta- or exascale systems efficiently due to the increasing complexity of applications and systems. The mSPMD programming model has been designed to adopt multiple programming models across different architecture levels. Instead of invoking a single parallel program on millions of processor cores, multiple SPMD programs of moderate sizes can be worked together in the mSPMD programming model. As components of the mSPMD programming model, XMP has been supported. Fault-tolerance features, correctness checks, and some numerical libraries’ implementations in the mSPMD programming model have been presented.