CompoundFS: Compounding I/O Operations in Firmware File Systems


Yujie Ren, Rutgers University; Jian Zhang, ShanghaiTech University; Sudarsun Kannan, Rutgers University


We introduce CompoundFS, a firmware-level file system that combines multiple filesystem I/O operations into a single compound operation to reduce software overheads. The overheads include frequent interaction (e.g., system calls), data copy, and the VFS overheads between user-level application and the storage stack. Further, to exploit the compute capability of modern storage, CompoundFS also provides a capability to offload simple I/O data processing operations to the device-level CPUs, which further provides an opportunity to reduce interaction with the filesystem, move data, and free-up host CPU for other operations. Preliminary evaluation of CompoundFS against the state-of-the-art user-level, kernel-level, and firmware-level file systems using microbenchmarks and a real-world application shows up to 178% and 75% performance gains, respectively.

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@inproceedings {254262,
author = {Yujie Ren and Jian Zhang and Sudarsun Kannan},
title = {CompoundFS: Compounding I/O Operations in Firmware File Systems},
booktitle = {12th {USENIX} Workshop on Hot Topics in Storage and File Systems (HotStorage 20)},
year = {2020},
url = {},
publisher = {{USENIX} Association},
month = jul,

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