Student Research Poster: A Low Complexity Cache Sharing Mechanism to Address System Fairness

Shared caches have become, de facto, the common design choice in current multi-cores, ranging from embedded devices to high-performance processors. In these systems, requests from multiple applications compete for the cache resources, degrading to different extents their progress, quantified as the performance of individual applications compared to isolated execution. The difference between the progresses of the running applications yields the system to unpredictable behavior and causes a fairness problem. This problem can be addressed by carefully partitioning cache resources among the contending applications, but to be effective, a partitioning approach needs to estimate per-application progress. This work proposes Fair-Progress Cache Partitioning (FPCP), a low-overhead cache partitioning approach which addresses fairness by distributing cache resources among applications depending on their progress. To estimate progress, we have implemented two state-of-the-art performance models, ASM and PTCA, which estimate, at runtime, the performance a given application would have if executed in isolation.