Addressing a workload characterization study to the design of consistency protocols

Shared Virtual Memory (SVM) provides a low-cost and effective way to implement the shared-memory programming paradigm. SVMs utilize a number of concepts that include consistency models/protocols, sharing patterns, false sharing, and fragmentation issues. The range of issues encountered in an SVM introduces a level of complexity and presents a challenge to many SVM researchers. This paper presents a careful study of SVM systems focusing on how the workload characteristics can affect the performace of consistency protocols. This knowledge is used to propose a novel consistency protocol that improves the system performance. This paper pursues two main goals: (i) to illustrate how different SVM workload characteristics are interrelated, and (ii) to motivate the design of a new multiple-writer memory consistency protocol. To achieve the first goal, we provide a detailed workload characterization analysis and discussion on how consistency models and protocols work. To achieve the second goal, we describe a software-based SVM protocol that achieves better performance than a hardware protocol proposed in the literature. In some workloads, the speedup obtained over the baseline protocol is more than 20%.