Thread migration and communication minimization in DSM systems

Networks of workstations are characterized by dynamic resource capacities. Such environments can only be efficiently exploited by applications that are dynamically reconfigurable. The paper explores mechanisms and policies that enable online reconfiguration of shared memory applications through thread migration. We describe the design and preliminary performance of a distributed shared memory (DSM) system that performs online remappings of threads to nodes based on sharing behavior. Our system obtains complete sharing information through a novel correlation tracking phase that avoids the thread thrashing that characterizes previous approaches. This information is used to evaluate the communication required by a given thread mapping and to predict the resulting performance.