Parallel Ray-Tracing with a Transactional DSM S. Frenz, M. Schoettner, R. Goeckelmann, P. Schulthess Ulm University, Distributed Systems Department
[email protected] Abstract Equally important is the automatic consistency management of replicated data in the DSM. Many Distributed Shared Memory (DSM) is a well-known consistency models have been proposed by the DSM alternative to explicit message passing and remote community [3]. Weak and weaker consistency models procedure call. Numerous DSM systems and consistency were introduced and became thus more efficient but also models have been proposed in the past. The Plurix harder to program. Originally, DSM was developed to project implements a DSM operating system (OS) storing allow execution of parallel programs written for data and code within the DSM. Our DSM storage expensive multi-processor machines on cheap commodity features a new consistency model (transactional clusters without major modifications. But using weak consistency) combining restartable transactions with an consistency models required artful modifications to the optimistic synchronization scheme instead of relying on a source code. We believe that this requirement is one of hard to use weak consistency model. In this paper we the reasons why the DSM concept is still not widely evaluate our system for the first time with a real parallel accepted, not even for new application fields. application, a parallel ray-tracer. The measurements Considering this defect the Plurix project implements show that our DSM scales quite well for this application the first OS storing data and code within the DSM. By even though we are using a strong consistency model.