Dirty-Block Tracking in a Direct-Mapped DRAM Cache with Self-Balancing Dispatch

Recently, processors have begun integrating 3D stacked DRAMs with the cores on the same package, and there have been several approaches to effectively utilizing the on-package DRAMs as caches. This article presents an approach that combines the previous approaches in a synergistic way by devising a module called the dirty-block tracker to maintain the dirtiness of each block in a dirty region. The approach avoids unnecessary tag checking for a write operation if the corresponding block in the cache is not dirty. Our simulation results show that the proposed technique achieves a 10.3% performance improvement on average over the state-of-the-art DRAM cache technique.