LFOC+: A Fair OS-level Cache-Clustering Policy for Commodity Multicore Systems
<|reference_start|>LFOC+: A Fair OS-level Cache-Clustering Policy for Commodity Multicore Systems: 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 from performance monitoring counters to classify applications at runtime based on the degree of cache sensitivity and contentiousness, and effectively separates cache-sensitive applications from aggressor programs to improve fairness, while providing acceptable system throughput.   We implemented LFOC+ in the Linux kernel and evaluated it on a real system featuring an Intel Skylake processor, where we compare its effectiveness to that of four previously proposed cache-clustering policies. Our experimental analysis 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 by 9\% and 4.9\% on average.<|reference_end|>
@article{saez2024lfoc+:,
    title={LFOC+: A Fair OS-level Cache-Clustering Policy for Commodity Multicore
  Systems},
    author={Juan Carlos Saez, Fernando Castro, Graziano Fanizzi and Manuel
  Prieto-Matias},
    journal={IEEE Transactions on Computers, 71(8), pp. 1952-1967, 1 Aug. 2022},
    year={2024},
    doi={10.1109/TC.2021.3112970},
    archivePrefix={arXiv},
    eprint={2402.07693},
    primaryClass={cs.AR}
}