Download or read book Lazy Release Consistency for Software Distributed Shared Memory written by Rice University. Dept. of Computer Science and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: These reductions are especially significant for programs that exhibit false sharing and make extensive use of locks."

Download or read book Lazy Release Consistency for Distributed Shared Memory written by Rice University. Dept. of Computer Science and published by . This book was released on 1995 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "A software distributed shared memory (DSM) system allows shared memory parallel programs to execute on networks of workstations. This thesis presents a new class of protocols that has lower communication requirements than previous DSM protocols, and can consequently achieve higher performance. The lazy release consistent protocols achieve this reduction in communication by piggybacking consistency information on top of existing synchronization transfers. Some of the protocols also improve performance by speculatively moving data. We evaluate the impact of these features by comparing the performance of a software DSM using lazy protocols with that of a DSM using previous eager protocols. We found that seven of our eight applications performed better on the lazy system, and four of the applications showed performance speedups of at least 18%. As part of this comparison, we show that the cost of executing the slightly more complex code of the lazy protocols is far less important than the reduction in communication requirements. We also compare the lazy performance with that of a hardware supported shared memory system that uses processors and caches similar to those of the workstations running our DSM. Our DSM system was able to approach, and in one case even surpass, the performance of the hardware system for applications with coarse-grained parallelism, but the hardware system performed significantly better for programs with fine-grained parallelism. Overall, the results indicate that DSMs using lazy protocols have become a viable alternative for high-performance parallel processing."

Download or read book Delay Tolerant Lazy Release Consistency for Distributed Shared Memory in Opportunistic Networks written by Chance Ray Eary and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Opportunistic networking (ON), a concept which allows a mobile wireless device to dynamically interact with other wireless devices in its immediate vicinity, is a field with great potential to improve the utility of itinerant computational platforms. While ONs increase a device's ability to interact with its peers, the fleeting and intermittent connections between devices make many traditional computer collaboration paradigms, such as distributed shared memory (DSM), virtually untenable. DSM systems, developed for traditional networks, rely on relatively stable, consittent connections among participating nodes. In an ON, connectivity among nodes is distributed in time and space making it useful for delay tolerant applications only. When devices are disconnected their ability to collaborate is interrupted and their computing power underutilized until such time as they encounter their computing partners again. Because nodes within an ON are assumed to have no advance knowledge that they will encounter a specific device in the future, periods of disconnection between nodes could be lengthy or potentially infnite. This thesis proposes delay tolerant lazy release consistency (DTLRC) for implementing distributed shared memory in opportunistic networking environments. DTLRC permits mobile devices to remain independently productive while separated and provides a mechanism for nodes to regain coherence of shared memory if and when they meet again. DTLRC allows nodes to make use of results produced on shared memory while disconnected. Simulations using experimentally determined data traces demonstrate that DTLRC is a viable concept for enhancing cooperation among mobile wireless devices in an opportunistic networking environment.

Download or read book Distributed Shared Memory written by Jelica Protic and published by John Wiley & Sons. This book was released on 1997-08-10 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers present in this text survey both distributed shared memory (DSM) efforts and commercial DSM systems. The book discusses relevant issues that make the concept of DSM one of the most attractive approaches for building large-scale, high-performance multiprocessor systems. The authors provide a general introduction to the DSM field as well as a broad survey of the basic DSM concepts, mechanisms, design issues, and systems. The book concentrates on basic DSM algorithms, their enhancements, and their performance evaluation. In addition, it details implementations that employ DSM solutions at the software and the hardware level. This guide is a research and development reference that provides state-of-the art information that will be useful to architects, designers, and programmers of DSM systems.

Download or read book Lazy Release Consistency for Hardware coherent Multiprocessors written by University of Rochester. Dept. of Computer Science and published by . This book was released on 1994 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Release consistency is a widely accepted memory model for distributed shared memory systems. It provides significant opportunities for a coherence protocol to improve performance by delaying and buffering coherence operations. Different protocol implementations exploit these opportunities to different extents. Eager release consistency represents the state of the art for hardware-coherent multiprocessors, while lazy release consistency has been shown to provide better performance for software distributed shared memory (DSM). Several of the optimizations performed by lazy protocols have the potential to improve the performance of hardware-coherent multiprocessors, but their complexity has precluded a hardware implementation. With the advent of programmable protocol processors it may become possible to use them after all. We present and evaluate a lazy release-consistent protocol suitable for machines with dedicated protocol processors. This protocol admits multiple concurrent writers, sends write notices concurrently with computation, and delays invalidations until acquire operations. We also consider a lazier protocol that delays sending write notices until release operations. Our results indicate that the first protocol outperforms eager release consistency by as much as 20% across a variety of applications. The lazier protocol, on the other hand, is unable to recoup its high synchronization overhead. This represents a qualitative shift from the DSM world, where lazier protocols always yield performance improvements. We also study protocol performance under a variety of architectural settings and show that the performance gap between lazy and eager implementations of release consistency will increase on future machines. Based on our results, we conclude that machines with flexible hardware support for coherence should use protocols based on lazy release consistency, but in a less 'aggressively lazy' form than is appropriate for DSM."

Download or read book Support for Software Distributed Shared Memory on Clusters of Heterogeneous Workstations written by Subhabrata Saha and published by . This book was released on 2002 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lazy consistency for software distributed shared memory written by Pete Keleher and published by . This book was released on 1991 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Fault Tolerant Distributed Shared Memory System written by Cheryl Kaye DeMatteis and published by . This book was released on 1996 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recoverable Distributed Shared Memory Under Sequential and Relaxed Consistency written by and published by . This book was released on 1995 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed shared memory (DSM) implemented on a cluster of workstations is an increasingly attractive platform for executing parallel scientific applications. Checkpointing and rollback techniques can be used in such a system to allow the computation to progress in spite of the temporary failure of one or more processing nodes. The complexity and overhead inherent in traditional message-passing checkpointing techniques can be reduced by taking advantages of specific properties of DSM. In this paper we show that, if designed correctly, a DSM system only needs to consider a subset of message-passing dependencies for correct rollback. A passive server model of DSM computation is described that allows a loosening of dependency restrictions by considering the events involved in interactions between nodes as atomic. An ownership timestamp scheme is used to eliminate many of the dependencies related to keeping directories consistent. The schemes can be implemented in DSM hardware by simply redesigning the directory at the network interface. Finally, we show that by relaxing the memory consistency model and using lazy release consistency, it is possible to further relax dependency restrictions. (AN).

Download or read book Aggressive Release Consistency and Efficient Lock Implementation for Software Distributed Shared Memory written by Shiwa S. Fu and published by . This book was released on 1997 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shared Memory Consistency Models written by Abdul Naeem and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The shared memory systems should support parallelization at the computation (multiprocessor), communication (Network-on-Chip, NoC) and memory architecture levels to exploit the potential performance benefits. Such systems are facing the critical issues of memory consistency and coherence. Memory consistency issue arises due to the unconstrained operations which sometimes lead to the unexpected behavior of the systems. Memory consistency models are used to resolve this issue. Relaxed or weaker consistency models enforce less ordering constraints on the memory operations and exploit system optimizations compared to the stricter models. This book discusses the novel realization schemes and scalability analysis of strict Sequential Consistency (SC) model and relaxed memory consistency models: Total Store Ordering (TSO), Partial Store Ordering (PSO), Weak Ordering (WO), Release Consistency (RC), and Protected Release Consistency (PRC) in the NoC based distributed shared memory multiprocessor systems. This study should help the average readers and professionals to understand the critical issue of memory consistency both in the NoC based systems and general purpose multiprocessor systems.

Download or read book Handbook on Parallel and Distributed Processing written by Jacek Blazewicz and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, authors from academia and practice provide practitioners, scientists and graduates with basic methods and paradigms, as well as important issues and trends across the spectrum of parallel and distributed processing. In particular, they cover such fundamental topics as efficient parallel algorithms, languages for parallel processing, parallel operating systems, architecture of parallel and distributed systems, management of resources, tools for parallel computing, parallel database systems and multimedia object servers, as well as the relevant networking aspects. A chapter is dedicated to each of parallel and distributed scientific computing, high-performance computing in molecular sciences, and multimedia applications for parallel and distributed systems.

Download or read book Object Based Distributed Programming written by Rachid Guerraoui and published by Springer Science & Business Media. This book was released on 1994-05-27 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest has grown rapidly over the past dozen years in the application of object-oriented programming and methods to the development of distributed, open systems. This volume presents the proceedings of a workshop intended to assess the current state of research in this field and to facilitate interaction between groups working on very different aspects of object-oriented distributed systems. The workshop was held as part of the 1993 European Conference on Object-Oriented Programming (ECOOP '93). Over fifty people submitted position papers and participated in the workshop, and almost half presented papers. The presented papers were carefully reviewed and revised after the workshop, and 14 papers were selected for this volume.

Download or read book SCI Scalable Coherent Interface written by Hermann Hellwagner and published by Springer. This book was released on 2006-12-29 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scalable Coherent Interface (SCI) is an innovative interconnect standard (ANSI/IEEE Std 1596-1992) addressing the high-performance computing and networking domain. This book describes in depth one specific application of SCI: its use as a high-speed interconnection network (often called a system area network, SAN) for compute clusters built from commodity workstation nodes. The editors and authors, coming from both academia and industry, have been instrumental in the SCI standardization process, the development and deployment of SCI adapter cards, switches, fully integrated clusters, and software systems, and are closely involved in various research projects on this important interconnect. This thoroughly cross-reviewed state-of-the-art survey covers the complete hardware/software spectrum of SCI clusters, from the major concepts of SCI, through SCI hardware, networking, and low-level software issues, various programming models and environments, up to tools and application experiences.

Download or read book Languages Compilers and Run Time Systems for Scalable Computers written by David O'Hallaron and published by Springer. This book was released on 2003-06-29 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the strictly refereed post-workshop proceedings of the 4th International Workshop on Languages, Compilers, and Run-Time Systems for Scalable Computing, LCR '98, held in Pittsburgh, PA, USA in May 1998. The 23 revised full papers presented were carefully selected from a total of 47 submissions; also included are nine refereed short papers. All current issues of developing software systems for parallel and distributed computers are covered, in particular irregular applications, automatic parallelization, run-time parallelization, load balancing, message-passing systems, parallelizing compilers, shared memory systems, client server applications, etc.

Download or read book Distributed Systems for System Architects written by Paulo Veríssimo and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary audience for this book are advanced undergraduate students and graduate students. Computer architecture, as it happened in other fields such as electronics, evolved from the small to the large, that is, it left the realm of low-level hardware constructs, and gained new dimensions, as distributed systems became the keyword for system implementation. As such, the system architect, today, assembles pieces of hardware that are at least as large as a computer or a network router or a LAN hub, and assigns pieces of software that are self-contained, such as client or server programs, Java applets or pro tocol modules, to those hardware components. The freedom she/he now has, is tremendously challenging. The problems alas, have increased too. What was before mastered and tested carefully before a fully-fledged mainframe or a closely-coupled computer cluster came out on the market, is today left to the responsibility of computer engineers and scientists invested in the role of system architects, who fulfil this role on behalf of software vendors and in tegrators, add-value system developers, R&D institutes, and final users. As system complexity, size and diversity grow, so increases the probability of in consistency, unreliability, non responsiveness and insecurity, not to mention the management overhead. What System Architects Need to Know The insight such an architect must have includes but goes well beyond, the functional properties of distributed systems.

Download or read book Encyclopedia of Parallel Computing written by David Padua and published by Springer Science & Business Media. This book was released on 2014-07-08 with total page 2211 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing over 300 entries in an A-Z format, the Encyclopedia of Parallel Computing provides easy, intuitive access to relevant information for professionals and researchers seeking access to any aspect within the broad field of parallel computing. Topics for this comprehensive reference were selected, written, and peer-reviewed by an international pool of distinguished researchers in the field. The Encyclopedia is broad in scope, covering machine organization, programming languages, algorithms, and applications. Within each area, concepts, designs, and specific implementations are presented. The highly-structured essays in this work comprise synonyms, a definition and discussion of the topic, bibliographies, and links to related literature. Extensive cross-references to other entries within the Encyclopedia support efficient, user-friendly searchers for immediate access to useful information. Key concepts presented in the Encyclopedia of Parallel Computing include; laws and metrics; specific numerical and non-numerical algorithms; asynchronous algorithms; libraries of subroutines; benchmark suites; applications; sequential consistency and cache coherency; machine classes such as clusters, shared-memory multiprocessors, special-purpose machines and dataflow machines; specific machines such as Cray supercomputers, IBM’s cell processor and Intel’s multicore machines; race detection and auto parallelization; parallel programming languages, synchronization primitives, collective operations, message passing libraries, checkpointing, and operating systems. Topics covered: Speedup, Efficiency, Isoefficiency, Redundancy, Amdahls law, Computer Architecture Concepts, Parallel Machine Designs, Benmarks, Parallel Programming concepts & design, Algorithms, Parallel applications. This authoritative reference will be published in two formats: print and online. The online edition features hyperlinks to cross-references and to additional significant research. Related Subjects: supercomputing, high-performance computing, distributed computing