Exploration of Migration and Replacement Policies for Dynamic NUCA over Tiled CMPs

Multicore processors have proliferated several domains ranging from small scale embedded systems to large data-centers, making tiled CMPs (TCMP) the essential next generation scalable architecture. More processors need proportionally large cache to support the concurrent applications. NUCA architectures help in managing the capacity and access time for such larger cache designs. Static NUCA (SNUCA) has a fixed address mapping policy whereas dynamic NUCA (DNUCA) allows blocks to relocate nearer to the processing cores at runtime. The DNUCA architectures are well explored for systems with centralized cache banks and having processors along the periphery. SNUCA is well understood and explored for tiled CMPs whereas the same is not the case for DNUCA. Towards exploring various implementations of DNUCA for tiled CMPs, this paper presents an architecture along with migration and replacement policies for tiled CMPs. Experimental results show improvements with respect to TCMP based SNUCA. We discuss the differences and challenges of TCMP based DNUCA compared to original DNUCA, and present results for different configurations of migration and replacement policies. Simulation results shows improvements over TCMP based SNUCA by 44.7% and 9.6% in terms of miss-rate and cycles per instruction (CPI) respectively.