¡¡	Chinese Journal of Computers   Full Text
Title	Smart Multihop Promotion for Non-Uniform Cache Architecture
Authors	WU Jun-Jie PAN Xiao-Hui YANG Xue-Jun
Address	(National Laboratory for Parallel and Distributed Processing, School of Computer, National University of Defense Technology, Changsha 410073)
Year	2009
Issue	No.10(1887¡ª1895)
Abstract &   Background	Abstract Non-Uniform cache architecture (NUCA) has almost been the trend of the large on-chip cache design. Data promotion technique moves frequently accessed data into cache banks closer to processors for reducing the access latency of NUCA. Hence, data promotion plays a significant role in NUCA optimizing. However, current promotion technique uses fixed promoting policy and does not take the real state of cache banks into account when promoting. Thus, it may push useful data in the promoted cache bank far from the processor, leading to cache pollution problem. This paper proposes smart multihop promotion, which can feel the status of the candidate banks for promotion and select the right target bank dynamically. The smart multihop promotion not only reduces the cache pollution problem, but also improves the performance of data promotion. Meanwhile, the smart multihop promotion makes use of the access path of processor and does not add extra accesses to cache banks. Finally, this paper gives test results to 15 benchmarks from NAS Parallel Benchmark and Livermore Benchmark using a full-system simulator. Compared with the current promotion technique, the evaluation results show that the smart multihop promotion achieves 1ª±50¡Á improvement in saved cycles per promoting operation on average and 2ª±61¡Á at best. Meanwhile, the approach improves IPC performance by 6ª±24% on average over current promotion and by 19ª±03% at best. Keywords Cache; NUCA; promotion; data migration; smart