Download or read book Power Efficient Scheduling for Hard Real time Systems on a Multiprocessor Platform written by Peter Joseph Nistler and published by . This book was released on 2009 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy aware Scheduling on Multiprocessor Platforms written by Dawei Li and published by Springer Science & Business Media. This book was released on 2012-10-19 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiprocessor platforms play important roles in modern computing systems, and appear in various applications, ranging from energy-limited hand-held devices to large data centers. As the performance requirements increase, energy-consumption in these systems also increases significantly. Dynamic Voltage and Frequency Scaling (DVFS), which allows processors to dynamically adjust the supply voltage and the clock frequency to operate on different power/energy levels, is considered an effective way to achieve the goal of energy-saving. This book surveys existing works that have been on energy-aware task scheduling on DVFS multiprocessor platforms. Energy-aware scheduling problems are intrinsically optimization problems, the formulations of which greatly depend on the platform and task models under consideration. Thus, Energy-aware Scheduling on Multiprocessor Platforms covers current research on this topic and classifies existing works according to two key standards, namely, homogeneity/heterogeneity of multiprocessor platforms and the task types considered. Under this classification, other sub-issues are also included, such as, slack reclamation, fixed/dynamic priority scheduling, partition-based/global scheduling, and application-specific power consumption, etc.

Download or read book Multiprocessor Scheduling for Real Time Systems written by Sanjoy Baruah and published by Springer. This book was released on 2015-01-02 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of both theoretical and pragmatic aspects of resource-allocation and scheduling in multiprocessor and multicore hard-real-time systems. The authors derive new, abstract models of real-time tasks that capture accurately the salient features of real application systems that are to be implemented on multiprocessor platforms, and identify rules for mapping application systems onto the most appropriate models. New run-time multiprocessor scheduling algorithms are presented, which are demonstrably better than those currently used, both in terms of run-time efficiency and tractability of off-line analysis. Readers will benefit from a new design and analysis framework for multiprocessor real-time systems, which will translate into a significantly enhanced ability to provide formally verified, safety-critical real-time systems at a significantly lower cost.

Download or read book Energy aware Scheduling on Multiprocessor Platforms written by Dawei Li and published by Springer Science & Business Media. This book was released on 2012-10-20 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiprocessor platforms play important roles in modern computing systems, and appear in various applications, ranging from energy-limited hand-held devices to large data centers. As the performance requirements increase, energy-consumption in these systems also increases significantly. Dynamic Voltage and Frequency Scaling (DVFS), which allows processors to dynamically adjust the supply voltage and the clock frequency to operate on different power/energy levels, is considered an effective way to achieve the goal of energy-saving. This book surveys existing works that have been on energy-aware task scheduling on DVFS multiprocessor platforms. Energy-aware scheduling problems are intrinsically optimization problems, the formulations of which greatly depend on the platform and task models under consideration. Thus, Energy-aware Scheduling on Multiprocessor Platforms covers current research on this topic and classifies existing works according to two key standards, namely, homogeneity/heterogeneity of multiprocessor platforms and the task types considered. Under this classification, other sub-issues are also included, such as, slack reclamation, fixed/dynamic priority scheduling, partition-based/global scheduling, and application-specific power consumption, etc.

Download or read book Energy Efficient Scheduling for Hard Real time Systems written by Da He and published by . This book was released on 2013 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Efficient Scheduling Techniques for Real time Embedded Systems written by Rajesh Babu Prathipati and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Battery-powered portable embedded systems have been widely used in many applications. These embedded systems have to concurrently perform a multitude of complex tasks under stringent time constraints. As these systems become more complex and incorporate more functionality, they became more power-hungry. Thus, reducing power consumption and extending battery lifespan while guaranteeing the timing constraints has became a critical aspect in designing such systems. This gives rise to three aspects of research: (i) Guaranteeing the execution of the hard real-time tasks by their deadlines, (ii) Determining the minimum voltage under which each task can be executed, and (iii) Techniques to take advantage of run-time variations in the execution times of tasks. In this research, we present techniques that address the above aspects in single and multi processor embedded systems. We study the performance of the proposed techniques on various benchmarks in terms of energy savings.

Download or read book Network and Parallel Computing written by Chen Ding and published by Springer Science & Business Media. This book was released on 2010-08-30 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the IFIP International Conference, NPC 2010, held in Zhengzhou, China, in September 2010. The 39 papers presented were carefully selected from 89 submissions. The papers are organized in topical sections on Parallelization and Optimization, Parallel Algorithms, Network, CPU and Multicore, Cloud and Grid Infrastructure, Network on Chip.

Download or read book Hard Real Time Computing Systems written by Giorgio C Buttazzo and published by Springer Science & Business Media. This book was released on 2011-09-10 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This updated edition offers an indispensable exposition on real-time computing, with particular emphasis on predictable scheduling algorithms. It introduces the fundamental concepts of real-time computing, demonstrates the most significant results in the field, and provides the essential methodologies for designing predictable computing systems used to support time-critical control applications. Along with an in-depth guide to the available approaches for the implementation and analysis of real-time applications, this revised edition contains a close examination of recent developments in real-time systems, including limited preemptive scheduling, resource reservation techniques, overload handling algorithms, and adaptive scheduling techniques. This volume serves as a fundamental advanced-level textbook. Each chapter provides basic concepts, which are followed by algorithms, illustrated with concrete examples, figures and tables. Exercises and solutions are provided to enhance self-study, making this an excellent reference for those interested in real-time computing for designing and/or developing predictable control applications.

Download or read book Energy Efficient Scheduling for Real time Systems written by Nikhil Gupta and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this dissertation is to extend the state of the art in real-time scheduling algorithms to achieve energy efficiency. Currently, Pfair scheduling is one of the few scheduling frameworks which can optimally schedule a periodic real-time taskset on a multiprocessor platform. Despite the theoretical optimality, there exist large concerns about efficiency and applicability of Pfair scheduling in practical situations. This dissertation studies and proposes solutions to such efficiency and applicability concerns. This dissertation also explores temperature aware energy management in the domain of real-time scheduling. The thesis of this dissertation is: the implementation efficiency of Pfair scheduling algorithms can be improved. Further, temperature awareness of a real-time system can be improved while considering variation of task execution times to reduce energy consumption. This thesis is established through research in a number of directions. First, we explore the applicability of Dynamic Voltage and Frequency Scaling (DVFS) feature in the underlying platform, within Pfair scheduled systems. We propose techniques to reduce energy consumption in Pfair scheduling by using DVFS. Next, we explore the problem of quantum size selection in Pfair scheduled system so that runtime overheads are minimized. We also propose a hardware design for a central Pfair scheduler core in a multiprocessor system to minimized the overheads and energy consumption of Pfair scheduling. Finally, we propose a temperature aware energy management scheme for tasks with varying execution times.

Download or read book Algorithms and Architectures for Parallel Processing written by Arrems Hua and published by Springer Science & Business Media. This book was released on 2009-07-10 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 9th International Conference on Algorithms and Architectures for Parallel Processing, ICA3PP 2009, held in Taipei, Taiwan, in June 2009. The 80 revised full papers were carefully reviewed and selected from 243 submissions. The papers are organized in topical sections on bioinformatics in parallel computing; cluster, grid and fault-tolerant computing; cluster distributed parallel operating systems; dependability issues in computer networks and communications; dependability issues in distributed and parallel systems; distributed scheduling and load balancing, industrial applications; information security internet; multi-core programming software tools; multimedia in parallel computing; parallel distributed databases; parallel algorithms; parallel architectures; parallel IO systems and storage systems; performance of parallel ditributed computing systems; scientific applications; self-healing, self-protecting and fault-tolerant systems; tools and environments for parallel and distributed software development; and Web service.

Download or read book Energy Aware Scheduling for Real Time Embedded Systems written by Muhammad Khurram Bhatti and published by LAP Lambert Academic Publishing. This book was released on 2012-04 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-time embedded systems have become ubiquitous in our daily life. Due to their diversified usage, the research on these systems has confronted with many emerging challenges. One such challenge is to reduce power and energy consumption while maintaining assurance that timing constraints will be met. Power densities in microprocessors are almost doubled every three years. As energy is power integrated over time, supplying the required energy may become prohibitively expensive, or even technologically infeasible. This is particularly difficult in portable systems that heavily rely on batteries for energy, and will become even more critical as battery capacities are increasing at a much slower rate than power consumption. This book presents four contributions that are based on the thesis that energy-efficiency of Real-time Embedded Systems and scheduling are closely related problems and therefore, should be tackled together for optimal results. Contributions of this book are: 1) Two-level Hierarchical Scheduling Algorithm for Multiprocessor Systems, 2) Assertive Dynamic Power Management Scheme, 3) Deterministic Stretch-to-Fit DVFS Technique, and 4) Hybrid Power Management Scheme.

Download or read book Memory Efficient Scheduling for Multicore Real time Systems written by Ahmed Alhammad and published by . This book was released on 2016 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern real-time systems are becoming increasingly complex and requiring significant computational power to meet their demands. Since the increase in uniprocessor speed has slowed down in the last decade, multicore processors are now the preferred way to supply the increased performance demand of real-time systems. A significant amount of work in the real-time community has focused on scheduling solutions for multicore processors for both sequential and parallel real-time tasks. Even though such solutions are able to provide strict timing guarantees on the overall response time of real-time tasks, they rely on the assumption that the worst-case execution time (WCET) of each individual task is known. However, physical shared resources such as main memory and I/O are heavily employed in multicore processors. These resources are limited and therefore subject to contention. In fact, the execution time of one task when run in parallel with other tasks is significantly larger than the execution time of the same task when run in isolation. In addition, the presence of shared resources increases the timing unpredictability due to the conflicts generated by multiple cores. As a result, the adoption of multicore processors for real-time systems is dependent upon solving such sources of unpredictability. In this dissertation, we investigate memory bus contention. In particular, two main problems are associated with memory contention: (1) unpredictable behavior and (2) hindrance of performance. We show how to mitigate these two problems through scheduling. Scheduling is an attractive tool that can be easily integrated into the system without the need for hardware modifications. We adopt an execution model that exposes memory as a resource to the scheduling algorithm. Thus, the theory of real-time multiprocessor scheduling, that has seen significant advances in recent years, can be utilized to schedule both processor cores and memory. Since the real-time workload on multicore processors can be modeled as sequential or parallel tasks, we also study parallel task scheduling by taking memory time into account.

Download or read book Soft Real Time Systems Predictability vs Efficiency written by Giorgio C Buttazzo and published by Springer Science & Business Media. This book was released on 2006-07-02 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hard real-time systems are very predictable, but not sufficiently flexible to adapt to dynamic situations. They are built under pessimistic assumptions to cope with worst-case scenarios, so they often waste resources. Soft real-time systems are built to reduce resource consumption, tolerate overloads and adapt to system changes. They are also more suited to novel applications of real-time technology, such as multimedia systems, monitoring apparatuses, telecommunication networks, mobile robotics, virtual reality, and interactive computer games. This unique monograph provides concrete methods for building flexible, predictable soft real-time systems, in order to optimize resources and reduce costs. It is an invaluable reference for developers, as well as researchers and students in Computer Science.

Download or read book Systematic Methodology for Real Time Cost Effective Mapping of Dynamic Concurrent Task Based Systems on Heterogenous Platforms written by Zhe Ma and published by Springer Science & Business Media. This book was released on 2007-08-26 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: A genuinely useful text that gives an overview of the state-of-the-art in system-level design trade-off explorations for concurrent tasks running on embedded heterogeneous multiple processors. The targeted application domain covers complex embedded real-time multi-media and communication applications. This material is mainly based on research at IMEC and its international university network partners in this area over the last decade. In all, the material those in the digital signal processing industry will find here is bang up-to-date.

Download or read book Resource efficient Scheduling of Multiprocessor Mixed criticality Real time Systems written by Jaewoo Lee and published by . This book was released on 2017 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timing guarantee is critical to ensure the correctness of embedded software systems that interact with the physical environment. As modern embedded real-time systems evolves, they face three challenges: resource constraints, mixed-criticality, and multiprocessors. This dissertation focuses on resource-efficient scheduling techniques for mixed-criticality systems on multiprocessor platforms.While Mixed-Criticality (MC) scheduling has been extensively studied on uniprocessor platforms, the problem on multiprocessor platforms has been largely open. Multiprocessor algorithms are broadly classified into two categories: global and partitioned. Global scheduling approaches use a global run-queue and migrate tasks among processors for improved schedulability. Partitioned scheduling approaches use per processor run-queues and can reduce preemption/migration overheads in real implementation. Existing global scheduling schemes for MC systems have suffered from low schedulability. Our goal in the first work is to improve the schedulability of MC scheduling algorithms. Inspired by the fluid scheduling model in a regular (non-MC) domain, we have developed the MC-Fluid scheduling algorithm that executes a task with criticality-dependent rates. We have evaluated MC-Fluid in terms of the processor speedup factor: MC-Fluid is a multiprocessor MC scheduling algorithm with a speed factor of 4/3, which is known to be optimal. In other words, MC-Fluid can schedule any feasible mixed-criticality task system if each processor is sped up by a factor of 4/3. Although MC-Fluid is speedup-optimal, it is not directly implementable on multiprocessor platforms of real processors due to the fractional processor assumption where multiple task can be executed on one processor at the same time. In the second work, we have considered the characteristic of a real processor (executing only one task at a time) and have developed the MC-Discrete scheduling algorithm for regular (non-fluid) scheduling platforms. We have shown that MC-Discrete is also speedup-optimal. While our previous two works consider global scheduling approaches, our last work considers partitioned scheduling approaches, which are widely used in practice because of low implementation overheads. In addition to partitioned scheduling, the work considers the limitation of conventional MC scheduling algorithms that drops all low-criticality tasks when violating a certain threshold of actual execution times. In practice, the system designer wants to execute the tasks as much as possible. To address the issue, we have developed the MC-ADAPT scheduling framework under uniprocessor platforms to drop as few low-criticality tasks as possible. Extending the framework with partitioned multiprocessor platforms, we further reduce the dropping of low-criticality tasks by allowing migration of low-criticality tasks at the moment of a criticality switch. We have evaluated the quality of task dropping solution in terms of speedup factor. In existing work, the speedup factor has been used to evaluate MC scheduling algorithms in terms of schedulability under the worst-case scheduling scenario. In this work, we apply the speedup factor to evaluate MC scheduling algorithms in terms of the quality of their task dropping solution under various MC scheduling scenarios. We have derived that MC-ADAPT has a speedup factor of 1.618 for task dropping solution.

Download or read book Efficient Scheduling Algorithms for Real time Multiprocessor Systems written by University of Massachusetts at Amherst. Department of Computer and Information Science and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Intelligent Systems and Applications written by W.C.-C. Chu and published by IOS Press. This book was released on 2015-04-14 with total page 2244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of the International Computer Symposium 2014 (ICS 2014), held at Tunghai University, Taichung, Taiwan in December. ICS is a biennial symposium founded in 1973 and offers a platform for researchers, educators and professionals to exchange their discoveries and practices, to share research experiences and to discuss potential new trends in the ICT industry. Topics covered in the ICS 2014 workshops include: algorithms and computation theory; artificial intelligence and fuzzy systems; computer architecture, embedded systems, SoC and VLSI/EDA; cryptography and information security; databases, data mining, big data and information retrieval; mobile computing, wireless communications and vehicular technologies; software engineering and programming languages; healthcare and bioinformatics, among others. There was also a workshop on information technology innovation, industrial application and the Internet of Things. ICS is one of Taiwan's most prestigious international IT symposiums, and this book will be of interest to all those involved in the world of information technology.