Limited multiple-writer: An approach to dealing with false sharing in software DSMs

Abstract

False sharing is one of the most important factors impacting the performance of DSM (distributed shared memory) systems. The single-writer approach is simple, but it cannot avoid the ping-pong effect of the data page thrashing, while the multiple-writer approach is effective for false sharing but with high cost. This paper proposes a new approach, called limited multiple-writer (LMW) to handling multiple writers in software DSM. It distinguishes two kinds of multiple-writer as lock-based form and barrier-based form, and handles them with different policies. It discards theTwin andDiff in traditional multiple-writer approach, and simplifies the implementation of multiple-writer in software DSM systems. The implementation of LMW in a CVM (Coherent Virtual Machine) software DSM system, which is based on a network of workstations, is introduced. Evaluation results show that for some applications such as SOR (Successive Over-Relaxation), LU (Lower triangular and Upper triangular), FFT (Fast Fourier Transformation), and IS (Integer Sorting), LMW provides a significant reduction in execution time (11%, 16%, 33% and 46%) compared with the traditional multiple-writer approach on the platform.