Conclusions

We have implemented a high-performance software distributed shared memory protocol for clusters of PCs connected by Virtual Interface Architecture networks. In this paper, we describe the implementation of a Home-based Lazy Release Consistency DSM protocol on VIA and evaluate its performance on a eight node cluster of PCs using 7 benchmark applications from the Splash-2 suite.

We observe that the VIA primitives are a good match for the requirements of the software DSM communication model. We have learned from our performance study that desirable features for software DSM systems, like scatter-gather, broadcast support, are missing from VIA. Even though the memory registration mechanism imposes a limit on the problem size that can be handled with a zero-copy protocol, our performance studies reveal that copies do not affect the application performance adversely.

The experimental results show that VIA can be successfully used to support shared memory on clusters of PCs but further study is necessary to evaluate its scalability on larger clusters and for a larger set of applications.