  In recent years, computers based on the RISC-V architecture have raised broad
interest in the high-performance computing (HPC) community. As the RISC-V
community develops the core instruction set architecture (ISA) along with ISA
extensions, the HPC community has been actively ensuring HPC applications and
environments are supported. In this context, assessing the performance of
asynchronous many-task runtime systems (AMT) is essential. In this paper, we
describe our experience with porting of a full 3D adaptive mesh-refinement,
multi-scale, multi-model, and multi-physics application, Octo-Tiger, that is
based on the HPX AMT, and we explore its performance characteristics on
different RISC-V systems. Considering the (limited) capabilities of the RISC-V
test systems we used, Octo-Tiger already shows promising results and good
scaling. We, however, expect that exceptional hardware support based on
dedicated ISA extensions (such as single-cycle context switches, extended
atomic operations, and direct support for HPX's global address space) would
allow for even better performance results.

Distributed, Parallel, and Cluster Computing