Design and Optimization of Non-Volatile One-Memory Architecture (NVM-OMA)

非易失性存储器(NVM)领域的持续发展使具体的系统设置更接近现实，并允许使用NVM主存储器具体查看和调查系统和系统属性。在本项目第一阶段成功研究了NVM作为主内存和存储内存的统一使用的同时，我们注意到正确和结构化地处理产生的NVM系统的异构性是至关重要的，因此，在本项目第二阶段，我们将从为配备NVM的现代系统提供结构化和统一管理的角度来具体研究One Memory Architecture(OMA)的构建。OMA抽象不仅应该包括性能，还应该包括非功能属性，如易失性、数据保留、可靠性(磨损平衡)等。此外，OMA应该提供统一的抽象来处理系统软件中内存使用的异构性。除了考虑硬件的异构性外，我们还将主要关注软件的内存使用的异构性。堆、堆栈、数据和文本的典型存储器分段导致存储器区域的异类访问行为，即，文本段是只读的，而堆栈中的特定存储器区域可能导致频繁的写访问。我们的目标是明确地将这种异质性作为OMA的一部分。该项目由来自德国多特蒙德理工大学和KIT的两名首席研究员(PI)以及来自中国科学院、台湾大学和台湾长庚大学的三名PI组成。申请者群体是硬件-软件协同设计、嵌入式系统、非易失性存储器、节能设计、新兴技术和实时系统领域的专家。我们将继续采用非传统的方法来改变传统的内存使用方式，以使其对NVM更加友好。在NVM-OMA的第二阶段，该项目打算为到目前为止被广泛忽视的属性提供新的解决方案。总体而言，本项目阶段将把异构型NVM系统作为所有已开发方法的基本系统。我们计划使所有方法和解决方案适应内存层次结构中的各种NVM类型、粒度和级别。此外，我们将探索设计空间，并就如何决定采用正确的NVM类型开发方法和见解。与我们的自适应管理策略相结合，这最终允许构建一个内存架构。

Continuous development in the area of non-volatile memory (NVM) brings concrete system setups closer to reality and enables a concrete view and investigation of systems and system properties with NVM main memory. While we successfully studied the unified usage of NVM as main memory and storage memory in the first phase of this project, we have noticed that it is crucial to handle the heterogeneity of arising NVM systems properly and in a structured way.Thus, we will specifically study the construction of one memory architecture (OMA) under the aspect of providing a structured and unified way of management for modern NVM equipped systems in the second phase of this project. The OMA abstraction should cover not only performance but also non-functional properties like volatility, data retention, reliability (wear-leveling), etc. Furthermore, OMA should provide a unified abstraction to handle the heterogeneity of memory usage in the system software. Besides considering hardware heterogeneity, we will put a major focus on the heterogeneity of the memory usage of software. The typical memory segmentation with heap, stack, data and text results in heterogeneous access behavior of memory areas, i.e., the text segment is read only, whilst a specific memory region in the stack can result in frequent write accesses. Our objective is to explicitly consider such heterogeneity as part of OMA.The project is coupled by two principle investigators (PI) from TU Dortmund and KIT in Germany and three PIs from Academia Sinica, National Taiwan University, and Chang Gung University in Taiwan. The applicant groups are domain experts in hardware-software codesign, embedded systems, non-volatile memories, power-efficient designs, emerging technologies, and real-time systems. We will move forward with unconventional approaches to alter the classic way of memory usage in order to be more NVM-friendly. Within this second phase of NVM-OMA, the project intends to provide novel solutions for properties, which have been widely neglected so far. Overall, this project phase will take heterogeneous NVM systems as a basic system for all developed methods. We plan to make all methods and solutions adaptive to various NVM types, granularities, and levels within the memory hierarchy. Furthermore, we will explore the design space and develop methods and insights on how to decide for the right NVM type to be adopted. In combination with our adaptive management strategies, this ultimately allows the construction of one memory architecture.