An adaptive migratory home protocol for software DSM systems

In software distributed shared memory systems, home-based protocols are very good designs because of easy implementation, little memory overheads and good performance. The home-based protocols can be divided into two categories, the fix home protocol and the migratory home protocol. The fix home protocol produces less number of page faults than the migratory home protocol. The migratory home protocols can save the number of diff creating and diff propagation. For an application program, its execution behavior is suitable for the fixed home protocol in some time periods and is suitable for the migratory home protocol in some other time periods. A protocol that can be adapted between the fixed home protocol and the migratory home protocol is important for the performance of an application program. In this paper, we proposed an adaptive migratory home protocol, which combines the advantages of the fixed home and the migratory home protocols. In the adaptive migratory home protocol, the home node of a page can change the state of the page according the application behavior. To evaluate the adaptive migratory home protocol, we have implemented the proposed protocol along with the home-based protocol and the migratory home protocol. We tested eight application programs for the three protocols on the same platform. The experimental result shows that the home-based protocol works well for applications with sharing access pattern. The migratory home protocol has good performance for migratory access pattern. The performance of the adaptive migratory home protocol is in between these two protocols and performs well for most of the applications.