RCache: A Read-Intensive Workload-Aware Page Cache for NVM Filesystem  

作　　者：TU Yaofeng ZHU Bohong YANG Hongzhang HAN Yinjun SHU Jiwu 

机构地区：[1]State Key Laboratory of Mobile Network and Mobile Multimedia Technology,Shenzhen 518055,China [2]ZTE Corporation,Shenzhen 518057,China [3]Tsinghua University,Beijing 100084,China

出　　处：《ZTE Communications》2023年第1期89-94,共6页中兴通讯技术（英文版）

基　　金：supported by ZTE Industry⁃University⁃Institute Coopera⁃tion Funds under Grant No.HC⁃CN⁃20181128026.

摘　　要：Byte-addressable non-volatile memory(NVM),as a new participant in the storage hierarchy,gives extremely high performance in storage,which forces changes to be made on current filesystem designs.Page cache,once a significant mechanism filling the performance gap between Dynamic Random Access Memory(DRAM)and block devices,is now a liability that heavily hinders the writing performance of NVM filesystems.Therefore state-of-the-art NVM filesystems leverage the direct access(DAX)technology to bypass the page cache entirely.However,the DRAM still provides higher bandwidth than NVM,which prevents skewed read workloads from benefiting from a higher bandwidth of the DRAM and leads to sub-optimal performance for the system.In this paper,we propose RCache,a readintensive workload-aware page cache for NVM filesystems.Different from traditional caching mechanisms where all reads go through DRAM,RCache uses a tiered page cache design,including assigning DRAM and NVM to hot and cold data separately,and reading data from both sides.To avoid copying data to DRAM in a critical path,RCache migrates data from NVM to DRAM in a background thread.Additionally,RCache manages data in DRAM in a lock-free manner for better latency and scalability.Evaluations on Intel Optane Data Center(DC)Persistent Memory Modules show that,compared with NOVA,RCache achieves 3 times higher bandwidth for read-intensive workloads and introduces little performance loss for write operations.

关 键 词：storage system file system persistent memory 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]