SHF:Small:Data Structures and Transactions for Emerging Nonvolatile Memory

SHF：Small：新兴非易失性存储器的数据结构和事务

• 批准号: 1717712
• 负责人: Michael Scott
• 金额: $ 44.99万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1717712&HistoricalAwards=false
• 关键词: SHF; Small; Data; Structures; Transactions

Data that need to be persistent, either for the sake of long-term access or for recovery from system crashes, have traditionally been kept on disk and flash drives, which are very slow. Within the next few years, much faster persistent memory is expected to be widely available at reasonable cost, raising the possibility that file systems might be replaced, at least in part, by memory that is simply "always available." The intellectual merits of the project lie in addressing two key challenges to such "always available memory": first, ensuring that the values in memory in the wake of a system crash are always mutually consistent, despite the possibility that traditional caches often pass data to the memory out of order; second, safeguarding the structural integrity of persistent data despite the possibility that buggy programs may erroneously modify arbitrary memory locations. The project's broader significance and importance lie in the promise of significant improvements in programmability, reliability, and system performance, and in the ability to survive power outages and hardware failures at much lower cost than has previously been possible. This latter benefit may be of particular importance for ubiquitous sensors in the Internet of Things.The project builds on prior work by the principal investigator and colleagues, which has developed formal correctness criteria for persistent data, together with automatic methods to guarantee this correctness. The current project is pursuing three major research thrusts. First, it is developing a library of reusable, high-performance persistent data structures, with particular emphasis on exploiting high-level semantics to minimize instrumentation overhead, maintaining sufficient information to complete or undo partial operations in the wake of a program or system crash, and formalizing and proving correctness. Second, the project is developing techniques to compose persistent operations into larger atomic transactions. This work builds on past experience with hardware and software transactional memory, and encompasses both nonblocking and lock-based approaches. Particular emphasis is being placed on "boosting" the operations of persistent data structures so that they can serve as reversible high-level operations of a transactional system. Third, the project is developing mechanisms (including user-level daemons, compiler-based sandboxing, fine-grain memory protection, and the use of virtualization hardware) to ensure that persistent data is modified only by trusted library code, thereby safeguarding its structural integrity in the presence of buggy applications.

传统上，为了长期访问或从系统崩溃中恢复而需要持久化的数据都保存在磁盘和闪存驱动器上，但速度非常慢。 在接下来的几年内，速度更快的持久内存预计将以合理的成本广泛使用，从而提高了文件系统可能被“始终可用”的内存（至少部分）取代的可能性。该项目的智力优势在于解决了这种“始终可用的内存”的两个关键挑战：首先，确保系统崩溃后内存中的值始终相互一致，尽管传统缓存可能经常将数据无序地传递到内存；其次，保护持久数据的结构完整性，尽管有错误的程序可能会错误地修改任意内存位置。 该项目更广泛的意义和重要性在于有望显着改进可编程性、可靠性和系统性能，以及以比以前低得多的成本承受停电和硬件故障的能力。 后一个好处对于物联网中无处不在的传感器可能特别重要。该项目建立在首席研究员和同事之前的工作基础上，他们为持久数据制定了正式的正确性标准，以及保证这种正确性的自动方法。 当前的项目正在追求三个主要研究方向。 首先，它正在开发一个可重用、高性能持久数据结构库，特别强调利用高级语义来最小化检测开销，维护足够的信息以在程序或系统崩溃后完成或撤消部分操作，以及形式化和证明正确性。 其次，该项目正在开发将持久操作组合成更大的原子事务的技术。 这项工作建立在过去的硬件和软件事务内存经验的基础上，并包含非阻塞和基于锁的方法。 特别强调“增强”持久数据结构的操作，以便它们可以充当事务系统的可逆高级操作。 第三，该项目正在开发机制（包括用户级守护程序、基于编译器的沙箱、细粒度内存保护和虚拟化硬件的使用），以确保持久数据仅由可信库代码修改，从而在存在错误的应用程序时保护其结构完整性。

项目成果

Hodor: intra-process isolation for high-throughput data plane libraries

Hodor：高吞吐量数据平面库的进程内隔离

• 发表时间: 2019
• 期刊: Proceedings of the 2019 Usenix Annual Technical Conference
• 作者: Mohammad Hedayati, Spyridoula Gravani

Nonblocking Persistent Software Transactional Memory

非阻塞持久软件事务内存

• DOI: 10.1109/hipc50609.2020.00042
• 发表时间: 2020
• 期刊: and Analytics (HiPC
• 作者: Beadle, H. Alan;Cai, Wentao;Wen, Haosen;Scott, Michael L.
• 通讯作者: Scott, Michael L.

Interval-based memory reclamation

基于间隔的内存回收

• DOI: 10.1145/3178487.3178488
• 发表时间: 2018
• 期刊: Proceedings of the 23rd ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming
• 作者: Wen, Haosen;Izraelevitz, Joseph;Cai, Wentao;Beadle, H. Alan;Scott, Michael L.
• 通讯作者: Scott, Michael L.

Understanding and optimizing persistent memory allocation

• DOI: 10.1145/3381898.3397212
• 发表时间: 2020-03
• 期刊: Proceedings of the 2020 ACM SIGPLAN International Symposium on Memory Management
• 作者: Wentao Cai;Haosen Wen;H. A. Beadle;Chris Kjellqvist;Mohammad Hedayati;M. Scott

Leveraging hardware TM in Haskell

在 Haskell 中利用硬件 TM

• DOI: 10.1145/3293883.3295711
• 发表时间: 2019
• 期刊: Proceedings of the 24th Symposium on Principles and Practice of Parallel Programming
• 作者: Yates, Ryan;Scott, Michael L.
• 通讯作者: Scott, Michael L.