| 1. |
- Abdullah, Syed Md Jakaria, et al.
(författare)
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Towards Implementation of Virtual-Clustered Multiprocessor Scheduling in Linux
- 2013
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Ingår i: Proceedings of the 8th IEEE International Symposium on Industrial Embedded Systems, SIES 2013. - 9781479906581 ; , s. 97-100
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Konferensbidrag (refereegranskat)abstract
- Cluster based multiprocessor scheduling can be seen as a hybrid approach combining benefits of both partitioned and global scheduling. Virtual clustering further enhances it by providing dynamic cluster resource allocation and applying hierarchical scheduling techniques. Over the years, the study of virtual cluster scheduling has been limited to theoretical analysis. In this paper, we present our initial ideas about implementing virtual cluster scheduling in Linux. The purpose of this implementation is twofold: (i) we would like to demonstrate the feasibility of its implementation in an operating system, without modifying the kernel source code, (ii) we present practical insights on the overhead of implementing this framework.
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| 2. |
- Ashjaei, Mohammad, et al.
(författare)
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Performance Analysis of Master-Slave Multi-Hop Switched Ethernet Networks
- 2013
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Ingår i: Proceedings of the 8th IEEE International Symposium on Industrial Embedded Systems, SIES 2013. - 9781479906581 ; , s. 280-289
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Konferensbidrag (refereegranskat)abstract
- There is an increasing trend towards using switched Ethernet in real-time distributed systems due to features like absence of collisions and high throughput. Nevertheless, a few problems persist, in particular related to priority inversion and limited length in queues. In this paper we focus on a protocol which uses a master-slave technique over standard switched Ethernet in order to overcome such problems, namely FTT-SE protocol. We present an improved response time analysis for such a network and we compare, analytically and with simulations, the results achieved with Network Calculus on a worst-case scenario. We show that our proposed response time analysis gives tighter bounds compared to Network Calculus. Moreover, we compare the performance of different solutions to scale the FTT-SE protocol with respect to the bandwidth utilization. Finally, we propose a new architecture to improve the average performance of master-slave switched Ethernet networks.
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| 3. |
- Liu, Meng, et al.
(författare)
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An EVT-based Worst-Case Response Time Analysis of Complex Real-Time Systems
- 2013
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Ingår i: Proceedings of the 8th IEEE International Symposium on Industrial Embedded Systems, SIES 2013. - 9781479906581 ; , s. 249-258
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Konferensbidrag (refereegranskat)abstract
- In recent years, the complexity of real-time embedded systems has increased dramatically. For those modern real-time systems, the limitations of original static Response Time Analysis (RTA) become more and more conspicuous. Most static analysis methods not only require much detailed system information, but also only target to some specific system model with non-realistic assumptions. As a result, those methods may produce overly pessimistic results, making them unsuitable to be applied on a complex industrial system. The best system model may be the system itself. Therefore, statistical RTA, which can produce probabilistic analysis results based on samples provided by real systems or simulators, may become more expedient. Statistical RTA usually requires more relaxed assumptions and less system information than static RTA. In this paper, we present an Extreme Value Theory (EVT) based method to compute Worst-Case Response Time (WCRT) targeting complex real-time systems. In the evaluation phase, we have applied this method to the calculation of worst-case transmission delays of messages over Controller Area Network (CAN), and some comparisons with static RTA are also provided. According to the experimental results, as the system complexity increases, our approach performs much more stable and less pessimistic.
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| 4. |
- van den Heuvel, Martijn, et al.
(författare)
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Virtual scheduling for compositional real-time guarantees
- 2013
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Ingår i: Proceedings of the 8th IEEE International Symposium on Industrial Embedded Systems, SIES 2013. - 9781479906581 ; , s. 151-160
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Konferensbidrag (refereegranskat)abstract
- In this paper, we extend the compositional scheduling framework to enable the integration of an existing (legacy) application as a component on a faster processor which needs to be shared with other components. After admission of this application into the framework, the integrated component still has to satisfy its tasks' deadline constraints and it must execute jobs in the same order as it did previously on the dedicated processor, regardless of the actual supply of processor resources. We propose a method - called virtual scheduling - which establishes this by reconstructing an appropriate order of delivering events. Virtual scheduling is therefore independent of the component-level scheduling policy and it is transparent to a component, so that it is even applicable without making modifications to the code or specification of the application.
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