Distance-aware round-robin mapping for large NUCA caches

In many-core architectures, memory blocks are commonly assigned to the banks of a NUCA cache by following a physical mapping. This mapping assigns blocks to cache banks in a round-robin fashion, thus neglecting the distance between the cores that most frequently access every block and the corresponding NUCA bank for the block. This issue impacts both cache access latency and the amount of on-chip network traffic generated. On the other hand, first-touch mapping policies, which take into account distance, can lead to an unbalanced utilization of cache banks, and consequently, to an increased number of expensive off-chip accesses. In this work, we propose the distance-aware round-robin mapping policy, an OS-managed policy which addresses the trade-off between cache access latency and number of off-chip accesses. Our policy tries to map the pages accessed by a core to its closest (local) bank, like in a firsttouch policy. However, our policy also introduces an upper bound on the deviation...

• Type: Journal
• Year: 2009
• Where: HIPC
• Authors: Alberto Ros, Marcelo Cintra, Manuel E. Acacio, José M. García
• Keywords: Cache, Cache Access Latency, Distributed And Parallel Computing, HIPC 2009, Off-chip Accesses