Porting hypre to heterogeneous computer architectures: Strategies and experiences

• DOI: 10.1016/j.parco.2021.102840
• Publication Date: 2021-09-20T04:38:31Z
• Authors: Robert D. Falgout; Ruipeng Li; Björn Sjögreen; Lu Wang; Ulrike Meier Yang
• Keywords: Porting; Multigrid method; Interface (matter); Macro; Symmetric multiprocessor system; Scope (computer science)

Abstract Linear systems are occurring in many applications, and solving them can take a large amount of the total simulation time. The high performance library hypre provides a variety of interfaces and linear solvers, including various multigrid methods, that have achieved good scalability on a variety of homogeneous parallel computer architectures. Heterogeneous architectures with nodes that have both CPUs and accelerators provide new challenges, since they require more fine-grained parallelism and reduced data movement between different memories on a single node as well as across nodes. We will discuss our experiences and strategies to port hypre to heterogeneous computers with accelerators, including the design of a new memory model, the use of abstractions, the BoxLoop macros in the structured and semi-structured interfaces, and the restructuring of algebraic multigrid (AMG) into modular components. We present numerical experiments comparing CPU and GPU performance for several test problems.