An Analytical Performance Model for Co-management of Last-Level Cache and Bandwidth Sharing

Processor cores in a chip multiprocessor (CMP) typically share a large last-level cache and the off-chip memory bandwidth. Previous studies demonstrate that explicit cache capacity and off-chip bandwidth partitioning can yield better overall system performance than without partitioning. However, little work has been done to study the interaction between cache capacity partitioning and off-chip bandwidth allocation. This paper develops a hybrid analytical model that takes into account the two partitioning problems together in order to capture their inter-dependence. With an elaborate case study, we show that an optimal resource management strategy would require a coordinated allocation of the cache and the off-chip bandwidth resources.