文献类型：期刊文献

英文题名：CFIO: A conflict-free I/O mechanism to fully exploit internal parallelism for Open-Channel SSDs

作者：Zhu, Jinbin[1,2];Wang, Liang[1,2];Xiao, Limin[1,2];Liu, Lei[1,2];Qin, Guangjun[3]

第一作者：Zhu, Jinbin

通讯作者：Wang, L[1];Xiao, LM[1]

机构：[1]Beihang Univ, State Key Lab Software Dev Environm, Beijing 100191, Peoples R China;[2]Beihang Univ, Sch Comp Sci & Engn, Beijing 100191, Peoples R China;[3]Beijing Union Univ, Smart City Coll, Beijing 100101, Peoples R China

第一机构：Beihang Univ, State Key Lab Software Dev Environm, Beijing 100191, Peoples R China

通讯机构：[1]corresponding author), Beihang Univ, State Key Lab Software Dev Environm, Beijing 100191, Peoples R China.

年份：2023

卷号：135

外文期刊名：JOURNAL OF SYSTEMS ARCHITECTURE

收录：;EI(收录号：20225213292148);Scopus(收录号：2-s2.0-85144479156);WOS:【SCI-EXPANDED(收录号:WOS:000906232500001)】；

基金：Acknowledgments This work was supported by the National Natural Science Foun-dation of China under Grant No. 62104014, the National Labora-tory of Software Development Environment, China under Grant No. SKLSDE-2022ZX-07.

语种：英文

外文关键词：NVMe SSDs; Open-Channel SSD; Access conflict; Conflict-free I; O management

摘要：I/O access conflicts make utilization within NVMe SSDs seriously low, which introduces unpredictable performance loss of NVMe SSDs. Although existing works adopt I/O isolation or conflict-aware I/O scheduling to avoid access conflicts, they can result in an unbalanced utilization and reduce the lifetime of NVMe SSDs. In this paper, we design and implement CFIO, a low-overhead conflict-aware I/O mechanism that achieves conflict-free I/Os to exploit the internal parallelism in NVMe SSDs. CFIO improves PU utilization and reduces I/O latency with two novel mechanisms. First, a conflict-free (CF) lane is proposed to eliminate conflicts by dividing I/O requests into conflict-free PU queues based on physical addresses. The PU queues correspond to the PU resources within the NVMe SSDs. Second, a k-RR scheduler is designed to dispatch reading and writing requests to NVMe SSDs in batches and separately. K-RR scheduler can fully exploit the internal parallelism of NVMe SSDs and form an I/O pipeline based on the dual registers of PU. Finally, we integrate CFIO into the LightNVM with Open-Channel NVMe SSD (OCSSD) and compare it with several existing solutions. Our evaluations show that CFIO improves the throughput of OCSSD by 19.32% and reduces its tail latency by 23.71%, compared to state-of-the-art methods.