Efficient Home-Based Protocols for Reducing Asynchronous Communication in Shared Virtual Memory Systems

In this thesis, an exhaustive evaluation of Distributed Shared Memory Systems known as Shared Virtual Memory Systems is performed. This kind of systems has characteristics that made them specially attractive, like their relatively low cost, high portability and shared memory programming paradigm. The evaluation is performed in two parts. In the first part, the design principles and the state of the art of the research related with this kind of systems is performed. In the second part, it is studied the behavior of a representative set of parallel workloads regarding to three axes of characterization intimately related with the performance of this kind of systems. While the first part points to the hypothesis that asynchronous communication is one of the main causes of performance loss, the second does not only confirm it, but also offers a detailed analysis of the workloads that shows useful information about the potential asynchronous communication attending to different system parameters. The evaluation results are used to propose two new protocols for this kind of systems that uses minimal hardware resources, reaching similar and in some cases superior performance to that obtained by systems that make use of specific hardware for reducing asynchronous communication. In particular, one of the proposed protocols is compared with a well-known hardware technique for reducing asynchronous communication, obtaining satisfactory and complementary results to the compared technique. All the modeled systems and techniques used in this work have been implemented and evaluated using a new simulation environment developed in the context of this work.