A Primer on Memory Persistency

A Primer on Memory Persistency
Author: Gogte Vaibhav
Publisher: Springer Nature
Total Pages: 95
Release: 2022-06-01
Genre: Technology & Engineering
ISBN: 303179205X

This book introduces readers to emerging persistent memory (PM) technologies that promise the performance of dynamic random-access memory (DRAM) with the durability of traditional storage media, such as hard disks and solid-state drives (SSDs). Persistent memories (PMs), such as Intel's Optane DC persistent memories, are commercially available today. Unlike traditional storage devices, PMs can be accessed over a byte-addressable load-store interface with access latency that is comparable to DRAM. Unfortunately, existing hardware and software systems are ill-equipped to fully avail the potential of these byte-addressable memory technologies as they have been designed to access traditional storage media over a block-based interface. Several mechanisms have been explored in the research literature over the past decade to design hardware and software systems that provide high-performance access to PMs.Because PMs are durable, they can retain data across failures, such as power failures and program crashes. Upon a failure, recovery mechanisms may inspect PM data, reconstruct state and resume program execution. Correct recovery of data requires that operations to the PM are properly ordered during normal program execution. Memory persistency models define the order in which memory operations are performed at the PM. Much like memory consistency models, memory persistency models may be relaxed to improve application performance. Several proposals have emerged recently to design memory persistency models for hardware and software systems and for high-level programming languages. These proposals differ in several key aspects; they relax PM ordering constraints, introduce varying programmability burden, and introduce differing granularity of failure atomicity for PM operations.This primer provides a detailed overview of the various classes of the memory persistency models, their implementations in hardware, programming languages and software systems proposed in the recent research literature, and the PM ordering techniques employed by modern processors.

A Primer on Memory Persistency

A Primer on Memory Persistency
Author: Vaibhav Gogte
Publisher:
Total Pages: 115
Release: 2022-02-09
Genre:
ISBN: 9781636393063

This book introduces readers to emerging persistent memory (PM) technologies that promise the performance of dynamic random-access memory (DRAM) with the durability of traditional storage media, such as hard disks and solid-state drives (SSDs). Persistent memories (PMs), such as Intel's Optane DC persistent memories, are commercially available today. Unlike traditional storage devices, PMs can be accessed over a byte-addressable load-store interface with access latency that is comparable to DRAM. Unfortunately, existing hardware and software systems are ill-equipped to fully avail the potential of these byte-addressable memory technologies as they have been designed to access traditional storage media over a block-based interface. Several mechanisms have been explored in the research literature over the past decade to design hardware and software systems that provide high-performance access to PMs. Because PMs are durable, they can retain data across failures, such as power failures and program crashes. Upon a failure, recovery mechanisms may inspect PM data, reconstruct state and resume program execution. Correct recovery of data requires that operations to the PM are properly ordered during normal program execution. Memory persistency models define the order in which memory operations are performed at the PM. Much like memory consistency models, memory persistency models may be relaxed to improve application performance. Several proposals have emerged recently to design memory persistency models for hardware and software systems and for high-level programming languages. These proposals differ in several key aspects; they relax PM ordering constraints, introduce varying programmability burden, and introduce differing granularity of failure atomicity for PM operations. This primer provides a detailed overview of the various classes of the memory persistency models, their implementations in hardware, programming languages and software systems proposed in the recent research literature, and the PM ordering techniques employed by modern processors.

A Primer on Hardware Prefetching

A Primer on Hardware Prefetching
Author: Babak Falsafi
Publisher: Springer Nature
Total Pages: 54
Release: 2022-06-01
Genre: Technology & Engineering
ISBN: 3031017439

Since the 1970’s, microprocessor-based digital platforms have been riding Moore’s law, allowing for doubling of density for the same area roughly every two years. However, whereas microprocessor fabrication has focused on increasing instruction execution rate, memory fabrication technologies have focused primarily on an increase in capacity with negligible increase in speed. This divergent trend in performance between the processors and memory has led to a phenomenon referred to as the “Memory Wall.” To overcome the memory wall, designers have resorted to a hierarchy of cache memory levels, which rely on the principal of memory access locality to reduce the observed memory access time and the performance gap between processors and memory. Unfortunately, important workload classes exhibit adverse memory access patterns that baffle the simple policies built into modern cache hierarchies to move instructions and data across cache levels. As such, processors often spend much time idling upon a demand fetch of memory blocks that miss in higher cache levels. Prefetching—predicting future memory accesses and issuing requests for the corresponding memory blocks in advance of explicit accesses—is an effective approach to hide memory access latency. There have been a myriad of proposed prefetching techniques, and nearly every modern processor includes some hardware prefetching mechanisms targeting simple and regular memory access patterns. This primer offers an overview of the various classes of hardware prefetchers for instructions and data proposed in the research literature, and presents examples of techniques incorporated into modern microprocessors.

Programming Persistent Memory

Programming Persistent Memory
Author: Steve Scargall
Publisher: Apress
Total Pages: 387
Release: 2020-01-09
Genre: Computers
ISBN: 1484249321

Beginning and experienced programmers will use this comprehensive guide to persistent memory programming. You will understand how persistent memory brings together several new software/hardware requirements, and offers great promise for better performance and faster application startup times—a huge leap forward in byte-addressable capacity compared with current DRAM offerings. This revolutionary new technology gives applications significant performance and capacity improvements over existing technologies. It requires a new way of thinking and developing, which makes this highly disruptive to the IT/computing industry. The full spectrum of industry sectors that will benefit from this technology include, but are not limited to, in-memory and traditional databases, AI, analytics, HPC, virtualization, and big data. Programming Persistent Memory describes the technology and why it is exciting the industry. It covers the operating system and hardware requirements as well as how to create development environments using emulated or real persistent memory hardware. The book explains fundamental concepts; provides an introduction to persistent memory programming APIs for C, C++, JavaScript, and other languages; discusses RMDA with persistent memory; reviews security features; and presents many examples. Source code and examples that you can run on your own systems are included. What You’ll Learn Understand what persistent memory is, what it does, and the value it brings to the industry Become familiar with the operating system and hardware requirements to use persistent memory Know the fundamentals of persistent memory programming: why it is different from current programming methods, and what developers need to keep in mind when programming for persistence Look at persistent memory application development by example using the Persistent Memory Development Kit (PMDK)Design and optimize data structures for persistent memoryStudy how real-world applications are modified to leverage persistent memoryUtilize the tools available for persistent memory programming, application performance profiling, and debugging Who This Book Is For C, C++, Java, and Python developers, but will also be useful to software, cloud, and hardware architects across a broad spectrum of sectors, including cloud service providers, independent software vendors, high performance compute, artificial intelligence, data analytics, big data, etc.

A Manager’s Primer on e-Networking

A Manager’s Primer on e-Networking
Author: Dragan Nikolik
Publisher: Springer Science & Business Media
Total Pages: 290
Release: 2012-09-10
Genre: Computers
ISBN: 9400708629

The implementation of Enterprise Networks or e-Networking is of paramount importance for organisations. Enterprise-wide networking would warrant that the components of information architecture are organised to harness more out of the organisation's computing power on the desktop. This would also involve establishment of networks that link the various but important subsystems of the enterprise. Our firm belief is that in order to gain a competitive edge the organisations need knowledge and sound strategy. This conviction is particularly true today, considering the pressures from international competition, environmental concerns and complicated ethical issues. This book, entitled A Manager's Primer on e-Networking, negotiates the hyper dimensions of the Internet through stories from myriad of Web sites with its fluent presentation and simple but chronological organisation of topics highlighting numerous opportunities and providing a solid starting point not only for inexperienced entrepreneurs and managers but anyone interested in applying information technology in the business. I sincerely hope the book will help as well many small and medium size companies and organisations to launch corporate networking successfully in order to attain their strategic objectives. Rajiv Jayashankar, Ph. D.

A Primer on Memory Persistency

A Primer on Memory Persistency
Author: Vaibhav Gogte
Publisher: Morgan & Claypool Publishers
Total Pages: 115
Release: 2022-02-09
Genre: Computers
ISBN: 1636393055

This book introduces readers to emerging persistent memory (PM) technologies that promise the performance of dynamic random-access memory (DRAM) with the durability of traditional storage media, such as hard disks and solid-state drives (SSDs). Persistent memories (PMs), such as Intel's Optane DC persistent memories, are commercially available today. Unlike traditional storage devices, PMs can be accessed over a byte-addressable load-store interface with access latency that is comparable to DRAM. Unfortunately, existing hardware and software systems are ill-equipped to fully avail the potential of these byte-addressable memory technologies as they have been designed to access traditional storage media over a block-based interface. Several mechanisms have been explored in the research literature over the past decade to design hardware and software systems that provide high-performance access to PMs. Because PMs are durable, they can retain data across failures, such as power failures and program crashes. Upon a failure, recovery mechanisms may inspect PM data, reconstruct state and resume program execution. Correct recovery of data requires that operations to the PM are properly ordered during normal program execution. Memory persistency models define the order in which memory operations are performed at the PM. Much like memory consistency models, memory persistency models may be relaxed to improve application performance. Several proposals have emerged recently to design memory persistency models for hardware and software systems and for high-level programming languages. These proposals differ in several key aspects; they relax PM ordering constraints, introduce varying programmability burden, and introduce differing granularity of failure atomicity for PM operations. This primer provides a detailed overview of the various classes of the memory persistency models, their implementations in hardware, programming languages and software systems proposed in the recent research literature, and the PM ordering techniques employed by modern processors.

Memory, Family, and Self

Memory, Family, and Self
Author: Giovanni Ciappelli
Publisher: BRILL
Total Pages: 321
Release: 2014-04-10
Genre: History
ISBN: 9004270752

The family book, a kind of diary written by and about the family for its various members, was established by scholars as a genre in Italy in the 1980s. Although initially regarded as an Italian genre, the family book can also be found in other parts of Europe. Nevertheless, the genre can be traced back to Florence, where it first emerged and consequently flourished with the lavish production of such documents. This abundance springs from the social structure of the city, where such texts were essential for establishing and cultivating the basis for the social promotion of Florentine families. This book presents a reconstruction of the evolution and persistency of Tuscan family books, as well as a study of several aspects of social history, including: reading and private libraries, domestic devotion, and the memory of historical events. Starting with the Renaissance, the investigation then broadens to the 17th-18th centuries and considers other forms of memory, such as private diaries and autobiographies. A final section is dedicated to the issue of memory in the egodocuments of early modern Europe. This book was translated by Susan Amanda George.

A Primer on Memory Consistency and Cache Coherence

A Primer on Memory Consistency and Cache Coherence
Author: Vijay Nagarajan
Publisher: Morgan & Claypool Publishers
Total Pages: 296
Release: 2020-02-04
Genre: Computers
ISBN: 1681737108

Many modern computer systems, including homogeneous and heterogeneous architectures, support shared memory in hardware. In a shared memory system, each of the processor cores may read and write to a single shared address space. For a shared memory machine, the memory consistency model defines the architecturally visible behavior of its memory system. Consistency definitions provide rules about loads and stores (or memory reads and writes) and how they act upon memory. As part of supporting a memory consistency model, many machines also provide cache coherence protocols that ensure that multiple cached copies of data are kept up-to-date. The goal of this primer is to provide readers with a basic understanding of consistency and coherence. This understanding includes both the issues that must be solved as well as a variety of solutions. We present both high-level concepts as well as specific, concrete examples from real-world systems. This second edition reflects a decade of advancements since the first edition and includes, among other more modest changes, two new chapters: one on consistency and coherence for non-CPU accelerators (with a focus on GPUs) and one that points to formal work and tools on consistency and coherence.

The Sunshine on My Face

The Sunshine on My Face
Author: Lydia Burdick
Publisher:
Total Pages: 0
Release: 2015
Genre: Health & Fitness
ISBN: 9781938870576

Text on illustrated pages in large print.