the importance of accounting for interrupts in multiprocessor real-time schedulability analsysis is discussed: three interrupt accounting methods, two of which are newly described here, are analyzed and compared.
ISBN:
(纸本)9780769537870
the importance of accounting for interrupts in multiprocessor real-time schedulability analsysis is discussed: three interrupt accounting methods, two of which are newly described here, are analyzed and compared.
In this paper we develop a novel real-time instruction-level loop scheduling technique to reduce leakage energy consumption for applications with loops on VLIW architecture. We first prove that the scheduling problem ...
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ISBN:
(纸本)9780769529752
In this paper we develop a novel real-time instruction-level loop scheduling technique to reduce leakage energy consumption for applications with loops on VLIW architecture. We first prove that the scheduling problem withthe minimum leakage energy consumption within a timing constraint is NP-complete. then, LEMLS (Leakage Energy Minimization Loop Scheduling) algorithm is designed to repeatedly regroup a loop based on rotation scheduling [3], and decrease leakage energy integrating with leakage power reduction mechanism. We conduct experiments on a set of DSP benchmarks based on the power model of the VLIW processors in [12]. the results show that our algorithm achieves significant leakage energy saving compared with list scheduling and the algorithm in [19].
Given the major advantages of productivity and safety, the use of garbage collection (GC) in real-timesystems has gained increasing attention. Guaranteeing garbage collection activities' worst-case execution time...
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ISBN:
(纸本)9780769529752
Given the major advantages of productivity and safety, the use of garbage collection (GC) in real-timesystems has gained increasing attention. Guaranteeing garbage collection activities' worst-case execution time (WCET) is necessary for a real-time system to perform scheduling and schedulability analysis. this paper describes a detailed GC cost model for incremental mark-and-sweep GC exemplified by a modified Boehm-Demers-Weiser (BDW) collector the GC cost model computes the WCET for garbage collection in terms of (1) the performance of collector operations and (2) the garbage collection load offered by a real-time task. Separating these aspects is a step along the road to an engineering approach to garbage collection in real-timesystems, allowing prediction of system, behavior from knowledge of component behavior and environmental specifications. the model incorporates the cost of write barriers that are needed to support incremental GC. To be useful for real-timesystems, a model's predicted WCET must be no less than the actual WCET However unreasonably large overestimates are also problematic as they may lead to the incorrect conclusion that the application cannot be feasibly scheduled. A pessimism metric assesses the degree to which the model's predictions exceed the measured worst-case cost in particular instances.
In this paper, we show how code can be generated at different levels of abstraction from a single source description. To this end, we use a model-driven development tool called Averest that is based on a synchronous p...
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ISBN:
(纸本)9781479908516
In this paper, we show how code can be generated at different levels of abstraction from a single source description. To this end, we use a model-driven development tool called Averest that is based on a synchronous programming language. We illustrate our approach by means of a case study from the domain of distributed real-time automotive embeddedsystems. this paper focuses thereby mainly on the use of the Averest toolkit to generate code at different levels of abstraction.
Many optimal uniprocessor schedulers, such as Earliest Deadline First (EDF) and Rate Monotonic (RM), do not have a good schedulability bound on multiprocessor systems. In this paper we study an on-line algorithm Earli...
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ISBN:
(纸本)9780769529752
Many optimal uniprocessor schedulers, such as Earliest Deadline First (EDF) and Rate Monotonic (RM), do not have a good schedulability bound on multiprocessor systems. In this paper we study an on-line algorithm Earliest Deadline First until Zero laxity (EDZL) for multiprocessor systems. A set of tasks scheduled by EDZL is scheduled using EDF until a job experiences a zero laxity. To avoid the job from missing its deadline, the priority of the job is immediately promoted to the highest priority. We derive the schedulability bound of 3/2+vertical bar u(max)-1/2 vertical bar for two-processor systems, where u(max) is the maximum utilization of an individual task in the given task set. We also discuss the best known upper bound and lower bound on EDZL schedulability conditions.
Hierarchical scheduling has recently been used to provide temporal isolation to embedded virtualised systems. Response time analysis is a common way to derive a schedulability test these systems. this paper points out...
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ISBN:
(纸本)9780769537870
Hierarchical scheduling has recently been used to provide temporal isolation to embedded virtualised systems. Response time analysis is a common way to derive a schedulability test these systems. this paper points out that response time analysis for hierarchical fixed-priority scheduling found in the literature is only exact for tasks of the highest priority domain. For the rest of the tasks is an upper bound. In our work, we provide the exact analysis and we compare it with previously published works.
Multi-core platforms are becoming the dominant computing architecture for next generation embeddedsystems. Nevertheless, designing, programming, and analyzing such systems is not easy and a solid methodology is still...
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ISBN:
(纸本)9780769537870
Multi-core platforms are becoming the dominant computing architecture for next generation embeddedsystems. Nevertheless, designing, programming, and analyzing such systems is not easy and a solid methodology is still missing. In this paper, we propose two powerful abstractions to model the computing power of a parallel machine, which provide a general interface for developing and analyzing real-timeapplications in isolation, independently of the physical platform. the proposed abstractions can be applied on top of different types of service mechanisms, such as periodic servers, static partitions, and P-fair time partitions. In addition, we developed the schedulability analysis of a set of real-time tasks on top of a parallel machine that is compliant withthe proposed abstractions.
Graphics processing units (GPUs) are becoming increasingly important in today's platforms as their increased generality allows for them to be used as powerfill co-processors. In this paper;we explore possible appl...
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ISBN:
(纸本)9780769545028
Graphics processing units (GPUs) are becoming increasingly important in today's platforms as their increased generality allows for them to be used as powerfill co-processors. In this paper;we explore possible applications for GPUs in real-timesystems, discuss the limitations and constraints imposed by current GPU technology, and present a summary of our research addressing many such constraints.
Soft real-time sporadic multiprocessor task systems are considered that include processing pipelines. Conditions are presented for guaranteeing bounded deadline tardiness in such systems under global EDF or FIFO sched...
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ISBN:
(纸本)9780769537870
Soft real-time sporadic multiprocessor task systems are considered that include processing pipelines. Conditions are presented for guaranteeing bounded deadline tardiness in such systems under global EDF or FIFO scheduling. "Early-releasing" is applied to make pipeline scheduling work-conserving. this lessens job response times in lightly-loaded systems.
this paper presents a partially-automated solution for the definition of test oracles for validating Simulink models. Since these models are widely used for the design of embeddedsystems, their thorough validation is...
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ISBN:
(纸本)9781479908516
this paper presents a partially-automated solution for the definition of test oracles for validating Simulink models. Since these models are widely used for the design of embeddedsystems, their thorough validation is key. Errors and misunderstandings in these models may preclude the correctness and reliability of the final system: a manual, human-intensive validation activity is not enough, and automated solutions are fundamental to improve the current state of the art. the paper also presents Apolom, a prototype oracle generator, and the results of two experiments.
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