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arXiv · 2412.18104

Interference-free Operating System: A 6 Years' Experience in Mitigating Cross-Core Interference in Linux

Zhaomeng Deng·Ziqi Zhang·Ding Li·Yao Guo·Yunfeng Ye·Yuxin Ren·Ning Jia·Xinwei Hu
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Abstract

Real-time operating systems employ spatial and temporal isolation to guarantee predictability and schedulability of real-time systems on multi-core processors. Any unbounded and uncontrolled cross-core performance interference poses a significant threat to system time safety. However, the current Linux kernel has a number of interference issues and represents a primary source of interference. Unfortunately, existing research does not systematically and deeply explore the cross-core performance interference issue within the OS itself. This paper presents our industry practice for mitigating cross-core performance interference in Linux over the past 6 years. We have fixed dozens of interference issues in different Linux subsystems. Compared to the version without our improvements, our enhancements reduce the worst-case jitter by a factor of 8.7, resulting in a maximum 11.5x improvement over system schedulability. For the worst-case latency in the Core Flight System and the Robot Operating System 2, we achieve a 1.6x and 1.64x reduction over RT-Linux. Based on our development experience, we summarize the lessons we learned and offer our suggestions to system developers for systematically eliminating cross-core interference from the following aspects: task management, resource management, and concurrency management. Most of our modifications have been merged into Linux upstream and released in commercial distributions.

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Zhaomeng Deng, Ziqi Zhang, Ding Li, Yao Guo, Yunfeng Ye, Yuxin Ren, Ning Jia, Xinwei Hu. 2024-12-24. Interference-free Operating System: A 6 Years' Experience in Mitigating Cross-Core Interference in Linux. https://doi.org/10.1109/rtss62706.2024.00034

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