Optimal Task Scheduling For Parallel Systems Using State Space Search
Download Optimal Task Scheduling For Parallel Systems Using State Space Search PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Optimal Task Scheduling For Parallel Systems Using State Space Search book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages.
Optimal Task Scheduling for Parallel Systems Using State-space Search
It is of ever-increasing importance that programs are able to take full advantage of the parallel systems on which they are run. Task scheduling is the problem of producing a schedule for a program, such that the tasks which make up the program are each allocated to a specific processor and in a specific order which minimises the overall run-time. This problem is NP-hard, so that the amount of work required grows exponentially as the number of tasks is increased. Although the NP-hardness of the problem usually discourages optimal solving, an optimal schedule can give a significant advantage in time critical systems or applications where a single schedule is reused many times. Previous research with branch-and-bound for optimal task scheduling has shown promise with small task graphs, being competitive with other methods. The state-space model used in that work has an obvious drawback of allowing many duplicate states to occur in the state-space, which theoretically causes a large amount of additional time and memory to be required. This thesis proposes a new state-space model called Allocation-Ordering (AO), which improves on older models through its carefully designed lack of duplicate states. AO divides the task scheduling problem into two distinct sub-problems (allocation and ordering) which are handled in sequence within the state-space. Experimental evaluation confirms the benefits of the model. The benefits of AO’s lack of duplicate states for other branch and bound algorithms are then explored, specifically variants with interesting properties such as parallelisation and low memory requirements. We then investigate its applicability to more complex task scheduling models: the model is first adapted to allow optimal task scheduling with related heterogeneous processors, and then to allow optimal task scheduling with task duplication. The success of the adaptation of AO shows its flexibility, and suggests it may have wide applicability to variants of the task scheduling problem, and potentially other problems.
Task Scheduling for Parallel Systems
A new model for task scheduling that dramatically improves the efficiency of parallel systems Task scheduling for parallel systems can become a quagmire of heuristics, models, and methods that have been developed over the past decades. The author of this innovative text cuts through the confusion and complexity by presenting a consistent and comprehensive theoretical framework along with realistic parallel system models. These new models, based on an investigation of the concepts and principles underlying task scheduling, take into account heterogeneity, contention for communication resources, and the involvement of the processor in communications. For readers who may be new to task scheduling, the first chapters are essential. They serve as an excellent introduction to programming parallel systems, and they place task scheduling within the context of the program parallelization process. The author then reviews the basics of graph theory, discussing the major graph models used to represent parallel programs. Next, the author introduces his task scheduling framework. He carefully explains the theoretical background of this framework and provides several examples to enable readers to fully understand how it greatly simplifies and, at the same time, enhances the ability to schedule. The second half of the text examines both basic and advanced scheduling techniques, offering readers a thorough understanding of the principles underlying scheduling algorithms. The final two chapters address communication contention in scheduling and processor involvement in communications. Each chapter features exercises that help readers put their new skills into practice. An extensive bibliography leads to additional information for further research. Finally, the use of figures and examples helps readers better visualize and understand complex concepts and processes. Researchers and students in distributed and parallel computer systems will find that this text dramatically improves their ability to schedule tasks accurately and efficiently.
Euro-Par 2015: Parallel Processing
This book constitutes the refereed proceedings of the 21st International Conference on Parallel and Distributed Computing, Euro-Par 2015, held in Vienna, Austria, in August 2015. The 51 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 190 submissions. The papers are organized in the following topical sections: support tools and environments; performance modeling, prediction and evaluation; scheduling and load balancing; architecture and compilers; parallel and distributed data management; grid, cluster and cloud computing; distributed systems and algorithms; parallel and distributed programming, interfaces and languages; multi- and many-core programming; theory and algorithms for parallel computation; numerical methods and applications; and accelerator computing.