Extreme Heterogeneity in High Performance Computing


Jeffrey S Vetter, Oak Ridge National Laboratory, US


Concerns about energy-efficiency and cost are forcing our community to reexamine system architectures, including the memory and storage hierarchy. While computing technologies have remained relatively stable for nearly two decades, new architectural features, such as heterogeneous cores, deep memory hierarchies, non-volatile memory (NVM), and near-memory processing, have emerged as possible solutions to address these concerns. However, we expect this "golden age"of architectural change to lead to extreme heterogeneity and it will have a major impact on software systems and applications. Software will need to be redesigned to exploit these new capabilities and provide some level of performance portability across these diverse architectures. In this talk, I will sample these emerging memory technologies, discuss their architectural and software implications, and describe several new approaches to address these challenges. One programming system we have designed allows users to program FPGAs using C and OpenACC directives, which facilitates portability to GPUs and CPUs. Another system is Papyrus (Parallel Aggregate Persistent -yru- Storage); it is a programming system that aggregates NVM from across the system for use as application data structures, such as vectors and key-value stores, while providing performance portability across emerging NVM hierarchies.