Paper ID: 668

Title: Latency Impact on Spin-Lock Algorithms for Modern Shared Memory
Multiprocessors

Authors: Jan C. Meyer, Anne C. Elster

Abstract: In 2006, John Mellor-Crummey and Michael Scott received the
Dijkstra Prize in Distributed Computing for their 1991 paper on
algorithms for scalable synchronization on shared memory
multiprocessors, which included a novel spin-lock algorithm
(a.k.a. MCS spin-lock) that carefully distributes spin locations in
memory to lessen the impact of bandwidth limitations on spin
algorithms. Their empirical work and architectural suggestions have
had a major impact on how the field has viewed spin-locks.

In this paper, we present an empirical study on recent architectures,
including the IBM P5+ and SGI ccNUMA architecture, which shows that
for these modern architectures, latency proves to have a greater
impact on performace than bandwidth.  Several testcases and a tabular
overview of our results are included.