RT Journal Article T1 LFOC+: A Fair OS-Level Cache-Clustering Policy for Commodity Multicore Systems A1 Sáez Alcaide, Juan Carlos A1 Castro Rodríguez, Fernando A1 Fanizzi, Graziano A1 Prieto Matías, Manuel AB Commodity multicore systems are increasingly adopting hardware support that enables the system software to partition the last-level cache (LLC). This support makes it possible for the operating system (OS) or the Virtual Machine Monitor (VMM) to mitigate shared-resource contention effects on multicores by assigning different co-running applications to various cache partitions. Recently cache-clustering (or partition-sharing) strategies have emerged as a way to improve system throughput and fairness on new platforms with cache-partitioning support. As opposed to strict cache-partitioning, which allocates separate cache partitions to each application, cache-clustering allows partitions to be shared by a group of applications. In this article we propose LFOC+, a fairness-aware OS-level cache-clustering policy for commodity multicore systems. LFOC+ tries to mimic the behavior of the optimal cache-clustering solution for fairness, which we could obtain for different workload scenarios by using a simulation tool. Our dynamic cache-clustering strategy continuously gathers data fromperformancemonitoring counters to classify applications at runtime based on the degree of cache sensitivity and contentiousness, and effectively separates cache-sensitive applications fromaggressor programs to improve fairness,while providing acceptable system throughput.We implemented LFOC+ in the Linux kernel and evaluated it on a real systemfeaturing an Intel Skylake processor, wherewe compare its effectiveness to that of four previously proposed cache-clustering policies. Our experimental análisis reveals that LFOC+ constitutes a lightweight OS-level policy and improves fairness relative to two other state-of-the-art fairness-aware strategies –Dunn and LFOC–, by up to 22% and up to 20.6%, respectively, and by9% and 4.9%on average. PB IEEE SN 0018-9340 YR 2022 FD 2022-08-01 LK https://hdl.handle.net/20.500.14352/95531 UL https://hdl.handle.net/20.500.14352/95531 LA eng NO J. C. Saez, F. Castro, G. Fanizzi and M. Prieto-Matias, "LFOC+: A Fair OS-Level Cache-Clustering Policy for Commodity Multicore Systems," in IEEE Transactions on Computers, vol. 71, no. 8, pp. 1952-1967, 1 Aug. 2022, doi: 10.1109/TC.2021.3112970 NO Gobierno de España NO Comunidad de Madrid NO Unión Europea (Fondo Europeo de Desarrollo Regional) DS Docta Complutense RD 12 abr 2025