Abstract The performance and energy efficiency offered by heterogeneous systems are highly useful for modern C++ applications, but the technological variety demands adequate portability and programmability. Initiatives such as Intel oneAPI facilitate the exploitation of Intel CPUs and GPUs, but not NVIDIA GPUs, which are present in systems of all kinds and are necessarily leveraged by CUDA technology. Frequently, only GPUs are used, leaving the CPU for management tasks, with the consequent loss of energy and system utilization. In this work, the CoexecutorRuntime system design and API are extended to transparently integrate backends of diverse technologies, unifying offloading mechanisms under a consistent co-execution API and scheduling runtime. Moreover, CPU-GPU co-execution of hybrid technologies is enabled to ensure performance portability. Experimental results show performance improvements for all programs studied, achieving average efficiencies of 0.91 and speedups of 1.31 over using only the GPU.

Abstract The path to the efficient exploitation of molecular dynamics simulators is strongly driven by the increasingly intensive use of accelerators. However, they suffer performance portability issues, making it necessary both to achieve technological combinations that allow taking advantage of each programming model and device, and to define more effective load distribution strategies that consider the simulation conditions. In this work, a new load balancing algorithm is presented, together with a set of optimizations to support hybrid co-execution in a runtime system for heterogeneous computing. The new extended design enables the exploitation of custom kernels and acceleration technologies altogether, being encapsulated for the rest of the runtime and its scheduling system. With this support, Mash algorithm allows to simultaneously leverage different workload distribution strategies, benefiting from the most advantageous one per device and technology. Experiments show that these proposals achieve an efficiency close to 0.90 and an energy efficiency improvement around 1.80 over the original optimized version.