基于LDPC读延迟的刷新和副本结合策略优化方案  

Policy Optimization Scheme of Refresh and Duplication Combination Based on LDPC Read Delay

作　　者：张耀方 李培轩 谢平[1,2,3,4,5] ZHANG Yaofang;LI Peixuan;XIE Ping(The College of Computer,Qinghai Normal University,Xining 810016,China;The State Key Laboratory of Tibetan Intelligent Information Processing and Application,Xining 810008,China;The Key Laboratory of Internet of Things of Qinghai Province,Xining 810016,China;Academy of Plateau Science and Sustainability,Xining 810016,China;Network Information Management Center of Qinghai Normal University,Xining 810006,China)

机构地区：[1]青海师范大学计算机学院,西宁810016 [2]省部共建藏语智能信息处理及应用国家重点实验室,西宁810008 [3]青海省物联网重点实验室,西宁810016 [4]高原科学与可持续发展研究院,西宁810016 [5]青海师范大学网络信息管理中心,西宁810006

出　　处：《计算机科学》2023年第7期38-45,共8页Computer Science

基　　金：国家自然科学基金(61762075);青海省物联网重点实验室项目(2022-ZJ-Y21)。

摘　　要：针对闪存存储器的密度增大和容量增加导致可靠性下降的问题,提出了一种基于LDPC读延迟的刷新和副本结合策略优化方案。通常,原始策略是在闪存存储器上加一个LDPC码模块,使用硬解码和软解码对数据进行纠错。而传统的刷新策略是在原始策略的基础上,在LDPC软解码未能纠错时,使用刷新策略对其进行纠错。本方案基于LDPC软解码7个量化级别的特性,并以此为判定条件,采用分析对比的方法确定刷新的条件是量化级别到达3,副本的条件是级别达到5,将两种方式合理地应用在LDPC软解码方式中。与前两种策略相比,所提方法缩短了闪存存储器的平均响应时间,在一定程度上提升了闪存存储器的读取性能。在模拟器disksim+ssd的扩展平台上进行仿真,实验结果表明,相比原始策略,该方案平均响应时间均值降低了10%;与传统的刷新策略相比,延长了闪存存储器的寿命。Aiming at the problem of reliability degradation caused by the increase of the density and capacity of flash memory,an optimization scheme of refresh and copy combination strategy based on LDPC read delay is proposed.In general,the original strategy is to add LDPC code module to flash memory and use hard and soft decoding to correct data errors.The traditional refresh strategy is based on the original strategy,when the LDPC soft decoding fails to correct the error,the refresh strategy is used to correct the error.The scheme is based on the characteristics of LDPC soft decoding 7 quantitative levels,and takes this as the judgment condition,using the method of analysis and comparison to determine that the condition of refresh is level 3,the condition of the copy is level 5,and the two methods are reasonably applied in the LDPC soft decoding mode.Compared with the previous two strategies,the average response time of flash memory is reduced,and the read performance of flash memory is improved to a certain extent.Simulation is performed on the extended platform of the simulator disksim+ssd,and experimental results show that,the average response time of this scheme is 10%shorter than that of the original strategy,and its flash memory lifetime is prolonged compared to traditional refresh strategies.

关 键 词：闪存存储器 低密奇偶校验码 刷新 副本 响应时间 寿命 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]