Specific Read-Only Data Management for Memory System Optimization

This paper proposes a new way of managing the cache by exploiting the difference of behavior in the memory system between read-only data and read-write data. A division of the existing cache-based memory hierarchy is proposed in order to create a dedicated data path for read-only data. In order to justify this approach, an analysis performed on a set of benchmarks shows that read-only data count for significant part of the working set and are less reused than read-write data. A transparent solution is proposed based on specific compilation support to separate automatically the memory accesses of read-only data at L1-level. This organization exploits the properties of the different sub-workloads in order to increase the overall data locality and data reuse. Simulated in a multicore environment, the evaluation of the new memory organization shows reduction of L1 misses up to 28.5%. Moreover, the messages issued on the interconnection network can be reduced up to 14.7% without any penalty on the performance.