Optimizing File Systems on Heterogeneous Memory by Integrating DRAM Cache with Virtual Memory Management


Yubo Liu, Yuxin Ren, Mingrui Liu, Hongbo Li, Hanjun Guo, Xie Miao, and Xinwei Hu, Huawei Technologies Co., Ltd.; Haibo Chen, Huawei Technologies Co., Ltd. and Shanghai Jiao Tong University


This paper revisits the usage of DRAM cache in DRAM-PM heterogeneous memory file systems. With a comprehensive analysis of existing file systems with cache-based and DAX-based designs, we show that both suffer from suboptimal performance due to excessive data movement. To this end, this paper presents a cache management layer atop heterogeneous memory, namely FLAC, which integrates DRAM cache with virtual memory management. FLAC is further incorporated with two techniques called zero-copy caching and parallel-optimized cache management, which facilitates fast data transfer between file systems and applications as well as efficient data synchronization/migration between DRAM and PM. We further design and implement a library file system upon FLAC, called FlacFS. Micro benchmarks show that FlacFS provides up to two orders of magnitude performance improvement over existing file systems in file read/write. With real-world applications, FlacFS achieves up to 10.6 and 9.9 times performance speedup over state-of-the-art DAX-based and cache-based file systems, respectively.

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@inproceedings {294783,
author = {Yubo Liu and Yuxin Ren and Mingrui Liu and Hongbo Li and Hanjun Guo and Xie Miao and Xinwei Hu and Haibo Chen},
title = {Optimizing File Systems on Heterogeneous Memory by Integrating {DRAM} Cache with Virtual Memory Management},
booktitle = {22nd USENIX Conference on File and Storage Technologies (FAST 24)},
year = {2024},
isbn = {978-1-939133-38-0},
address = {Santa Clara, CA},
pages = {71--87},
url = {https://www.usenix.org/conference/fast24/presentation/liu-yubo},
publisher = {USENIX Association},
month = feb

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