Mechanisms and interfaces for software-extended coherent shared memory
David Chaiken, Anant K. Agarwal · DSpace@MIT (Massachusetts Institute of Technology) · 1995
Software-extended systems use a combination of hardware and software to implement shared memory on large-scale multiprocessors. Hardware mechanisms accelerate common-case accesses, while software handles exceptional events. In order to provide fast memory access, this design strategy requires appropriate hardware mechanisms including caches, location-independent addressing, limited directories, processor access to the network, and a memory-system interrupt. Software-extended systems benefit from the flexibility of software, but they require a well-designed interface between their hardware and software components to do so. This dissertation proposes, designs, tests, measures, and models the novel softwareextended memory system of Alewife, a large-scale multiprocessor architecture. A working Alewife machine validates the design, and detailed simulations of the architecture (with up to 256 processors) show the cost versus performance trade-offs involved in building distributed shared memo...