ISSN 1000-1239 CN 11-1777/TP

计算机研究与发展 ›› 2018, Vol. 55 ›› Issue (9): 2029-2037.doi: 10.7544/issn1000-1239.2018.20180294

所属专题: 2018新型存储系统结构前沿技术专题

• 系统结构 • 上一篇    下一篇

一种基于微日志的持久性事务内存系统

陈娟1,胡庆达2,陈游旻2,陆游游2,舒继武2,杨晓辉1   

  1. 1(东南大学信息科学与工程学院 南京 210093); 2(清华大学计算机科学与技术系 北京 100084) (chenmj09@163.com)
  • 出版日期: 2018-09-01
  • 基金资助: 
    国家自然科学基金项目(61772300) This work was supported by the National Natural Science Foundation of China (61772300).

A Tiny-Log Based Persistent Transactional Memory System

Chen Juan1, Hu Qingda2, Chen Youmin2, Lu Youyou2, Shu Jiwu2, Yang Xiaohui1   

  1. 1(School of Information Science and Engineering, Southeast University, Nanjing 210093); 2(Department of Computer Science and Technology, Tsinghua University, Beijing 100084)
  • Online: 2018-09-01

摘要: 近年来,研究者们针对持久性内存良好的性能,设计了轻量级的持久性事务内存系统,它通过日志机制保证了事务的原子性和一致性.然而,相比于传统内存,持久性内存的存储单元往往具有更高的写延迟,并且存在有限的耐久性.发现现有的持久性事务内存系统存在日志机制带来过多的写操作问题:一方面,现有系统没有区分出事务中不同类型的写操作,即无论是对内存中已有数据的更新操作还是向事务中新分配区域添加数据的写操作,现有系统都采用相同的日志机制保证它们的一致性;另一方面,现有系统将更新操作的地址和数据等字段完整地持久化到日志中,即使其中大部分数据都可以通过压缩算法减少写入量.这2方面导致了冗余的日志操作,带来了额外的写延迟和写磨损.为了解决上述问题,设计并实现了一种基于微日志的持久性事务内存系统TLPTM,主要提出2个优化技术:1)分配操作感知的日志优化策略(allocation-aware log optimization, AALO),AALO有效地避免了向事务中新分配区域添加数据的写操作产生的日志开销;2)基于压缩算法的日志优化策略(compression-based log optimization, CBLO),CBLO将日志数据压缩后再写入到日志中,减少了日志操作的写开销.测试结果表明:相比于Mnemosyne,提出的日志优化策略AALO将事务性能提高了15%~24%,基于提出的2种优化技术实现的TLPTM将日志的写入总量降低了70%~81%.

关键词: 持久性内存, 事务内存系统, 性能, 耐久性, 日志机制

Abstract: In recent years,in order to exploit the performance advantage of persistent memory, researchers have designed various lightweight persistent transactional memory systems. Atomicity and consistency of transactions are mostly ensuredusing the logging mechanism. However,compared with conventional memory,memory cells of persistent memory tend to have higher write latency and limited endurance. This paper observes two problems in the existing persistent transactional memory systems: Firstly,existing systems do not distinguish between different types of write operations in the transaction. No matter whether the writes are updating existing data in memory or adding data to newly allocated memory, existing systems use the same logging mechanism to ensure consistency. Secondly,existing systems persist the address and data of every write operation to the log, even if most of them can be compressed to reduce the size. Both of the above problems lead to redundant log operations,resulting in extra write latency and write wearing. In order to solve the above problems,this paper designs and implements TLPTM,a tiny-log persistent transactional memory system. It is based on two optimization techniques: (1)AALO (allocation-aware log optimization), effectively avoids the logging overhead generated by the operations of adding data to newly allocated memory; (2)CBLO (compression-based log optimization), compresses the log before writing it to the NVM and reduces the overhead of logwriting. The experimental results show that compared with Mnemosyne, AALO improves the system performance by 15%~24%, and TLPTM using both optimizations reduces the write wearing of logging by 70%~81%.

Key words: persistent memory, transaction memory system, performance, endurance, logging mechanism

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