A comparison of three protocols for entry consistency maintenance based on MVA algorithm

In a distributed shared memory (DSM) system that implements an entry consistency model, shared data must be explicitly associated to a synchronization variable, and it can be accessed only in critical sections protected by that specific synchronization variable. The authors propose three protocols for entry consistency maintenance, ECU, ECI, and ECHBP, and they identify costs introduced by each of these consistency protocols, such as communication, processing and synchronization latencies. In order to determine synchronization latency we use a modified version of the MVA algorithm, while communication and processing latencies depend on an application's access behavior expressed by a probabilistic model. Finally, we determine processing power (e.g. speedup) of a system with N processors, taking into account communication, processing and synchronization latencies. In this way, we build a model for analytical comparison of the proposed protocols for a wide range of input parameters.