Development and Extension of Atomic Memory Operations in OpenSHMEM

Abstract

A distinguishing characteristic of OpenSHMEM compared to other PGAS programming model implementations is its support for atomic memory operations (AMOs). It provides a rich set of AMO interfaces supporting 32-bit and 64-bit datatypes. On most modern networks, network-implemented AMOs are known to outperform software-implemented AMOs. So, for achieving high-performance, an OpenSHMEM implementation should try to offload AMOs to the underlying network hardware when possible. Nevertheless, the challenge arises when (a) underlying hardware does not support full set of atomic operations, (b) more that one device is used, and (c) heterogeneous systems with multiple types of devices are involved. In this paper, we analyze the challenges and discuss potential solutions to address these challenges.