Efficient Memory Mapped File I/O for In-Memory File Systems


Jungsik Choi, Sungkyunkwan University; Jiwon Kim, ATTO Research; Hwansoo Han, Sungkyunkwan University


Recently, with the emergence of low-latency NVM storage, software overhead has become a greater bottleneck than storage latency, and memory mapped file I/O has gained attention as a means to avoid software overhead. However, according to our analysis, memory mapped file I/O incurs a significant amount of additional overhead. To utilize memory mapped file I/O to its true potential, such overhead should be alleviated. We propose map-ahead, mapping cache, and extended madvise techniques to maximize the performance of memory mapped file I/O on lowlatency NVM storage systems. This solution can avoid both page fault overhead and page table entry construction overhead. Our experimental results show throughput improvements of 38–70% in microbenchmarks and performance improvements of 6–18% in real applications compared to existing memory mapped I/O mechanisms.

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@inproceedings {203386,
author = {Jungsik Choi and Jiwon Kim and Hwansoo Han},
title = {Efficient Memory Mapped File {I/O} for {In-Memory} File Systems},
booktitle = {9th USENIX Workshop on Hot Topics in Storage and File Systems (HotStorage 17)},
year = {2017},
address = {Santa Clara, CA},
url = {https://www.usenix.org/conference/hotstorage17/program/presentation/choi},
publisher = {USENIX Association},
month = jul,