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| 2. |
- Behnam, Moris, et al.
(författare)
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Improved SIRAP analysis for synchronization in hierarchical scheduled real-time systems
- 2009
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Ingår i: Proceedings of 14th IEEE International Conference on Emerging Techonologies and Factory (ETFA'09). - Mallorca, Spain.
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Konferensbidrag (refereegranskat)abstract
- We present our ongoing work on synchronization in hierarchicalscheduled real-time systems, where tasks arescheduled using fixed-priority pre-emptive scheduling. Inthis paper, we show that the original local schedulabilityanalysis of the synchronization protocol SIRAP is verypessimistic when tasks of a subsystem access many globalshared resources. The analysis therefore suggests that asubsystem requires more CPU resources than necessary. Anew way to perform the schedulability analysis is presentedwhich can make the SIRAP protocol more efficient in termsof calculated CPU resource needs.
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| 4. |
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| 5. |
- Nemati, Farhang, et al.
(författare)
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Investigation of Implementing a Synchronization Protocol under Multiprocessors Hierarchical Scheduling
- 2009
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Ingår i: Proceedings of the Work-In-Progress (WIP) session of 14th IEEE International Conference on Emerging Techonologies and Factory (ETFA'09). - Mallorca, Spain.
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Konferensbidrag (refereegranskat)abstract
- In the multi-core and multiprocessor domain, there has been considerable work done on scheduling techniques assuming that real-time tasks are independent. In practice a typical real-time system usually share logical resources among tasks. However, synchronization in the multiprocessor area has not received enough attention. In this paper we investigate the possibilities of extending multiprocessor hierarchical scheduling to support an existing synchronization protocol (FMLP) in multiprocessor systems. We discuss problems regarding implementation of the synchronization protocol under the multiprocessor hierarchical scheduling.
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| 7. |
- Sandström, Kristian, et al.
(författare)
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On Jitter in Time Partitioned Real-Time Systems
- 2012
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Ingår i: 17th IEEE International Conference on Emerging Technologies & Factory Automation (ETFA'12), Work-in-Progress (WiP) session. - Krakow, Poland.
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Konferensbidrag (refereegranskat)
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| 8. |
- Sandström, Kristian, et al.
(författare)
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On Jitter in Time Partitioned Real-Time Systems
- 2012
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Ingår i: IEEE Symposium on Emerging Technologies and Factory Automation, ETFA 2012. - 978-146734737-2
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Konferensbidrag (refereegranskat)abstract
- Recent trends towards adopting hypervisors, hierarchical scheduling, and other virtualization technologies that achieve partitioned access to the CPU and other resources impose significant impact with respect to jitter performance in embedded real-time systems. In this paper we make a first step towards characterization, modeling and calculation of this jitter.
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| 10. |
- van den Heuvel, Martijn, et al.
(författare)
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Opaque Analysis for Resource Sharing in Compositional Real-Time Systems
- 2011
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Ingår i: 4th Workshop on Compositional Theory and Technology for Real-Time Embedded Systems (CRTS'11).
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Konferensbidrag (refereegranskat)abstract
- In this paper we propose opaque analysis methods to integrate dependent real-time components into hierarchical fixed-priority scheduled systems. To arbitrate mutually exclusive resource access between components, we consider two existing protocols: HSRP - comprising overrun with and without payback - and SIRAP. An opaque analysis allows to postpone the choice of a synchronization protocol until component integration time. First, we identify the sources of pessimism in the existing analysis techniques and we conclude that both protocols assume different models in their local analysis. In particular, the compo- sitional analysis for overrun with payback (OWP) is not opaque and is pessimistic. The latter makes OWP expensive compared to its counter part without a payback mechanism (ONP). This paper presents an opaque and less pessimistic OWP analysis. Secondly, SIRAP requires more timing information to perform a task-level schedulability analysis. In many practical situations, however, detailed timing characteristics of tasks are hard to obtain. We introduce an opaque analysis for SIRAP using the analysis of ONP to reduce the required timing information during the local analysis. We show that the analysis for ONP cannot deem systems schedulable which are infeasible with SIRAP. The SIRAP analysis may therefore reduce the required system resources of a component by sacrificing the choice for an arbitrary synchronization protocol at system integration time.
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