Processor scheduling in distributed-memory systems has received considerable attention in recent years. Several commercial distributed-memory systems use space-sharing processor scheduling. in space-sharing, the set o...
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ISBN:
(纸本)0818684038
Processor scheduling in distributed-memory systems has received considerable attention in recent years. Several commercial distributed-memory systems use space-sharing processor scheduling. in space-sharing, the set of processors in a system is partitioned and each partition is assigned for the exclusive use of a job. Space-sharing policies can be divided into fixed, static, or dynamic categories. For distributed-memory systems, dynamic policies incur high overhead. Thus, static policies are considered as these policies provide a better performance than the fixed policies. Several static policies have been proposed in the literature. In a previously proposed adaptive static policy, the partition size is a function of the number of queued jobs. This policy, however, tends to underutilize the system resources. To improve the performance of this policy, we propose a new policy in which the partition size is a function of the total number of jobs in the system, as opposed to only the queued jobs. The results presented here demonstrate that the new policy performs substantially better than the original policy for the various workload and system parameters. Another major contribution is the evaluation of the performance sensitivity to job structure, variances in inter-arrival times and job service times, and network topology.
The paper presents a model that is useful for developing resource allocation algorithms for distributed real-time systems that operate in dynamic environments. Interesting aspects of the model include dynamic environm...
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OpenMP has emerged as an important model and language extension for shared-memory parallel programming. On shared-memory platforms, OpenMP offers an intuitive, incremental approach to parallel programming. In this pap...
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This paper presents a theoretical and practical framework for constructing and reasoning about mobile agents. The framework is formulated as a process calculus and has two contributions. One of the contributions can m...
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This paper presents a theoretical and practical framework for constructing and reasoning about mobile agents. The framework is formulated as a process calculus and has two contributions. One of the contributions can model not only individual mobile agents but also a group of mobile agents because the calculus allows more than one mobile agent to be dynamically organized into a single mobile agent. The other contribution can exactly model many features of actual mobile agents, such as mobility and marshaling, which are often ignored in other existing frameworks but may seriously affect the correctness of mobile agents. To demonstrate the utility of the calculus, we constructed a practical mobile agent system whose agents can be naturally and strictly specified and verified in the calculus. The system also offers a security mechanism for mobile agents by using well-defined properties of the calculus.
softwaredistributed Shared Memory (DSM) systems can be used to provide a coherent shared address space on multicomputers and other parallelsystems without support for shared memory in hardware. The coherency softwar...
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Performance debugging and prediction for parallelsystems is a difficult problem. The difficulties in identifying performance bottlenecks stem from the need for an intimate understanding of the underlying architecture...
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Performance debugging and prediction for parallelsystems is a difficult problem. The difficulties in identifying performance bottlenecks stem from the need for an intimate understanding of the underlying architecture. It has been recognized that portability is an important requirement for parallel program development. However, this makes the task of performance debugging even more difficult. In this paper, we present a simulation based approach for performance prediction of portable parallel programs. We demonstrate it using Charm: a message driven programming environment, which provides program portability across a variety of shared and distributed memory MIMD parallelsystems. The proposed approach makes it possible to use a single debugging environment for the development of portable parallelsoftware. This environment can provide correctness and performance debugging support that provides the developer with valuable feedback for improving program performance.
In this paper we introduce a method for generating unstructured meshes in parallel which are partitioned in a 'good' way. When solving a partial differential equation on a paralleldistributed memory machine, ...
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In this paper we introduce a method for generating unstructured meshes in parallel which are partitioned in a 'good' way. When solving a partial differential equation on a paralleldistributed memory machine, the mesh should be decomposed so that the communication requirement of the numerical solver is minimised and also the amount of work to be performed on each processor is approximately equal. Most previous work in this area has concentrated on partitioning a mesh that has already been generated. We introduce a method which actually generates the partitioned mesh in parallel whilst producing a good quality decomposition and compare this method with other approaches. Copyright (C) 1996 Civil-Comp Limited and Elsevier Science Limited
Among all programming paradigms, component-based engineering stands as one of the most followed approaches for real world software development. Its emphasis on clean separation of concerns and reusability makes it app...
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Among all programming paradigms, component-based engineering stands as one of the most followed approaches for real world software development. Its emphasis on clean separation of concerns and reusability makes it appealing for both industrial and research purposes. The Grid Component Model (GCM) endorses this approach in the context of distributedsystems by providing all the means to define, compose and dynamically reconfigure component-based applications. While structural reconfiguration is one of the key features of GCM applications, this ability to evolve at runtime poses several challenges w.r.t reliability. In this paper we present Mefresa, a framework for reasoning on the structure of GCM applications. This contribution comes in the form of a formal specification mechanized in the Coq Proof Assistant. Our aim is to demonstrate the benefits of interactive theorem proving for the reasoning on software architectures. We provide a configuration and reconfiguration language for the safe instantiation of distributedsystems.
The fast Fourier transform (FFT) is a speed-up technique for calculating the discrete Fourier transform (DFT), which in turn is a discrete version of the continuous Fourier transform. The Fast Fourier Transform is use...
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ISBN:
(纸本)9781479941698
The fast Fourier transform (FFT) is a speed-up technique for calculating the discrete Fourier transform (DFT), which in turn is a discrete version of the continuous Fourier transform. The Fast Fourier Transform is used in linear systems analysis, antenna studies, optics, random process modeling, probability theory, quantum physics, and boundary-value problems, and has been very successfully applied to restoration of astronomical data. This paper formulates the one dimensional and two dimensional continuous and discrete Fourier transform, especially the fast Fourier transform, considers their parallel algorithms and reports the speed up of parallel computing in both shared memory and distributed memory modes.
Solfec is a computational code aimed at simulation of constrained multibody systems on distributed memory parallel computers. It implements an instance of the Contact Dynamics (CD) method by Moreau and Jean, hence the...
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Solfec is a computational code aimed at simulation of constrained multibody systems on distributed memory parallel computers. It implements an instance of the Contact Dynamics (CD) method by Moreau and Jean, hence the constraints are handled implicitly. One of the main goals of the software is to provide a user friendly platform for testing formulations and solution methods for the (dynamic) frictional contact problem. It is also meant to serve as a development platform for other aspects of time-stepping methods (e. g. contact detection, time integration, kinematic models). The purpose of this communication is to outline the algorithmic ideas behind Solfec, with an emphasis on the Gauss-Seidel constraints solver, a classical element of CD, efficiently implemented on a distributed memory model. The remaining topics include a dynamic domain decomposition balancing the computational load of the overall algorithm, and an accuracy measure for the frictional contact constraints. Solfec is an open-source software and can be downloaded from http://***/p/solfec. Copyright (C) 2011 John Wiley & Sons, Ltd.
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