Many modern applications have a significant operating system ( OS) component. The OS execution affects various architectural states, including the dynamic branch predictions, which are widely used in today's high-...
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Many modern applications have a significant operating system ( OS) component. The OS execution affects various architectural states, including the dynamic branch predictions, which are widely used in today's high-performance microprocessor designs to improve performance. This impact tends to become more significant as the designs become more deeply pipelined and more speculative. In this paper, we focus on the issues of understanding the OS effects on the branch predictions and designing architectural support to alleviate the bottlenecks that are created by misprediction. In this work, we characterize the control flow transfer of several emerging applications on a commercial OS. It was observed that the exception-driven, intermittent invocation of OS code and user/OS branch history interference increased misprediction in both user and kernel code. We propose two simple OS-aware control flow prediction techniques to alleviate the destructive impact of user/OS branch interference. The first consists of capturing separate branch correlation information for user and kernel code. The second involves using separate branch prediction tables for user and kernel code. We demonstrate in this paper that OS-aware branch predictions require minimal hardware modifications and additions. Moreover, the OS-aware branch predictions can be integrated with many existing schemes to further improve their performance. We studied the improvement contributed by OS-aware techniques to various branch prediction schemes ranging from the simple Gshare to the more advanced Agree, Multi-Hybrid, and Bi-Mode predictors. On the 32K-entry predictors, incorporating the OS-aware techniques yields up to 34 percent, 23 percent, 27 percent, and 9 percent prediction accuracy improvement on the Gshare, Multi-Hybrid, Agree, and Bi-Mode predictors, respectively.
This book offers an accessible guide to ubiquitous computing, with an emphasis on pervasive networking. It addresses various technical obstacles, such as connectivity, levels of service, performance, reliability and f...
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ISBN:
(数字)9789811334627
ISBN:
(纸本)9789811334610
This book offers an accessible guide to ubiquitous computing, with an emphasis on pervasive networking. It addresses various technical obstacles, such as connectivity, levels of service, performance, reliability and fairness. The focus is on describing currently available off-the-shelf technologies, novel algorithms and techniques in areas such as: underwater sensor networks, ant colony based routing, heterogeneous networks, agent based distributed networks, cognitive radio networks, real-time WSN applications, machine translation, intelligent computing and ontology based bit masking. By introducing the core topics and exploring assistive pervasive systems that draw on pervasive networking, the book provides readers with a robust foundation of knowledge on this growing field of research. Written in a straightforward style, the book is also accessible to a broad audience of researchers and designers who are interested in exploring pervasive computing further.
This book presents the state-of-the-art work in terms of searchable storage in cloud computing. It introduces and presents new schemes for exploring and exploiting the searchable storage via cost-efficient semantic ha...
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ISBN:
(数字)9789811327216
ISBN:
(纸本)9789811327209
This book presents the state-of-the-art work in terms of searchable storage in cloud computing. It introduces and presents new schemes for exploring and exploiting the searchable storage via cost-efficient semantic hashing computation. Specifically, the contents in this book include basic hashing structures (Bloom filters, locality sensitive hashing, cuckoo hashing), semantic storage systems, and searchable namespace, which support multiple applications, such as cloud backups, exact and approximate queries and image analytics. Readers would be interested in the searchable techniques due to the ease of use and simplicity. More importantly, all these mentioned structures and techniques have been really implemented to support real-world applications, some of which offer open-source codes for public use. Readers will obtain solid backgrounds, new insights and implementation experiences with basic knowledge in data structure and computersystems.
The foundations of computational complexity theory go back to Alan Thring in the 1930s who was concerned with the existence of automatic procedures deciding the validity of mathematical statements. The first example o...
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ISBN:
(数字)9783662049433
ISBN:
(纸本)9783540594369;9783642082177
The foundations of computational complexity theory go back to Alan Thring in the 1930s who was concerned with the existence of automatic procedures deciding the validity of mathematical statements. The first example of such a problem was the undecidability of the Halting Problem which is essentially the question of debugging a computer program: Will a given program eventu ally halt? Computational complexity today addresses the quantitative aspects of the solutions obtained: Is the problem to be solved tractable? But how does one measure the intractability of computation? Several ideas were proposed: A. Cobham [Cob65] raised the question of what is the right model in order to measure a "computation step" , M. Rabin [Rab60] proposed the introduction of axioms that a complexity measure should satisfy, and C. Shannon [Sha49] suggested the boolean circuit that computes a boolean function. However, an important question remains: What is the nature of computa tion? In 1957, John von Neumann [vN58] wrote in his notes for the Silliman Lectures concerning the nature of computation and the human brain that . . . logics and statistics should be primarily, although not exclusively, viewed as the basic tools of 'information theory'. Also, that body of experience which has grown up around the planning, evaluating, and coding of complicated logical and mathematical automata will be the focus of much of this information theory. The most typical, but not the only, such automata are, of course, the large electronic computing machines.
This book constitutes the proceedings of the 18th IFIP International Conference on Distributed Applications and Interoperable systems, DAIS 2018, held in Madrid, Spain, in June 2018.
ISBN:
(数字)9783319937670
ISBN:
(纸本)9783319937663
This book constitutes the proceedings of the 18th IFIP International Conference on Distributed Applications and Interoperable systems, DAIS 2018, held in Madrid, Spain, in June 2018.
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