On the complexity of fixed-priority scheduling of periodic, real-time tasks

Leung, Joseph Y.-T.; Whitehead, Jennifer

doi:10.1016/0166-5316(82)90024-4

Cited by 864 publications

(371 citation statements)

References 4 publications

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“…Some of these protocols [2,3,7] changed parameters in the IEEE 802.11 standard to be a function of deadlines, either choosing (i) inter-frame spacing (the amount of time that a station waits before transmitting) or (ii) the back-off times after a collision has occurred. These techniques are useful to meet deadlines because they can implement algorithms such as deadline monotonic [9]. But they have two drawbacks (i) they only approximate priority scheduling; it may happen that a high-priority message has to wait for one or many lower-priority messages and (ii) collisions can occur hence causing deadline misses.…”

Section: Related Workmentioning

confidence: 99%

Static-Priority Scheduling of Sporadic Messages on a Wireless Channel

Andersson

Tovar

2006

Lecture Notes in Computer Science

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Consider the problem of scheduling sporadic messages with deadlines on a wireless channel. We propose a collision-free medium access control (MAC) protocol which implements static-priority scheduling and present a schedulability analysis technique for the protocol. The MAC protocol allows multiple masters and is fully distributed; it is an adaptation to a wireless channel of the dominance protocol used in the CAN bus. But unlike that protocol, our protocol does not require a node having the ability to receive an incoming bit from the channel while transmitting to the channel. Abstract. Consider the problem of scheduling sporadic messages with deadlines on a wireless channel. We propose a collision-free medium access control (MAC) protocol which implements static-priority scheduling and present a schedulability analysis technique for the protocol. The MAC protocol allows multiple masters and is fully distributed; it is an adaptation to a wireless channel of the dominance protocol used in the CAN bus. But unlike that protocol, our protocol does not require a node having the ability to receive an incoming bit from the channel while transmitting to the channel. Static-Priority Scheduling of Sporadic Messages on a Wireless Channel

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Section: Related Workmentioning

confidence: 99%

Static-Priority Scheduling of Sporadic Messages on a Wireless Channel

Andersson

Tovar

2006

Lecture Notes in Computer Science

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“…In these cases, a larger time interval has to be considered in order to reach a cycle in the schedule, and the schedulability problem is NP-hard in the strong sense [24]. The only known exact schedulability tests are simulation-based like in [16] and have to consider the whole schedule, using a simulation interval representing finitely the infinite schedule, before concluding about the schedulability of a system, or the worst-case response time of the tasks.…”

Section: Feasibility and Simulation Intervalsmentioning

confidence: 99%

Periodicity of real-time schedules for dependent periodic tasks on identical multiprocessor platforms

Goossens¹,

Grolleau²,

Cucu-Grosjean³

2016

Real-Time Syst

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This paper gives and proves correct a simulation interval for any schedule generated by a deterministic and memoryless scheduler (i.e., one where the scheduling decision is the same and unique for any two identical system states) for identical multiprocessor platforms. We first consider independent periodic tasks, then generalize the simulation interval to tasks sharing critical resources, and subject to precedence constraints or self-suspension. The simulation interval is based only on the periods, release times and deadlines, and is independent from any other parameters. It is proved large enough to cover any feasible schedule produced by any deterministic and memoryless scheduler on multiprocessor platforms, including non conservative schedulers. To the best of our knowledge, this simulation interval covers the largest class of tasks systems and scheduling algorithms on identical multiprocessor platforms ever studied. This simulation interval is used to derive a simulation algorithm using a linear space complexity. Finally, a generic exact schedulability test based on simulation is presented. This test can be applied only when sustainability is consistent with online variability of the tasks' parameters.

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“…Although p i,j,k could be an integer variable of the problem for which the solver finds a valid value in its proposed solution, in a concern of drastically reducing the number of variables and therefore the complexity of the problem, one may also assume that priorities are assigned using DM [13], in which case p i,j,k = d i,j , and p i,j,k can be omitted in the description of the problem. Yet, it is necessary to evaluate if a certain partitioning leads to a valid solution.…”

Section: Fully-partitioned Distributed Multi-core Systemsmentioning

confidence: 99%

“…Azketa et al [12], addressed this problem by using the general purpose genetic algorithms. The authors initiate their genetic algorithm by assigning priorities using the HOPA heuristic [11], which is based on Deadline Monotonic (DM) priority assignment [13], and iterate over different solutions. To test schedulability they use the holistic analysis presented in Tindell et al [14] and Palencia et al [15,16] schedulability tests.…”

Section: Related Workmentioning

confidence: 99%

Allocation of Parallel Real-Time Tasks in Distributed Multi-core Architectures Supported by an FTT-SE Network

Garibay-Martínez¹,

Nelissen²,

Ferreira³

et al. 2015

Lecture Notes in Computer Science

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Distributed real-time systems such as automotive applications are becoming larger and more complex, thus, requiring the use of more powerful hardware and software architectures. Furthermore, those distributed applications commonly have stringent real-time constraints. This implies that such applications would gain in flexibility if they were parallelized and distributed over the system. In this paper, we consider the problem of allocating fixed-priority fork-join Parallel/Distributed real-time tasks onto distributed multi-core nodes connected through a Flexible Time Triggered Switched Ethernet network. We analyze the system requirements and present a set of formulations based on a constraint programming approach. Constraint programming allows us to express the relations between variables in the form of constraints. Our approach is guaranteed to find a feasible solution, if one exists, in contrast to other approaches based on heuristics. Furthermore, approaches based on constraint programming have shown to obtain solutions for these type of formulations in reasonable time. This implies that such applications would gain in flexibility if they were parallelized and distributed over the system. In this paper, we consider the problem of allocating fixed-priority fork-join Parallel/Distributed realtime tasks onto distributed multi-core nodes connected through a Flexible Time Triggered Switched Ethernet network. We analyze the system requirements and present a set of formulations based on a constraint programming approach. Constraint programming allows us to express the relations between variables in the form of constraints. Our approach is guaranteed to find a feasible solution, if one exists, in contrast to other approaches based on heuristics. Furthermore, approaches based on constraint programming have shown to obtain solutions for these type of formulations in reasonable time.

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On the complexity of fixed-priority scheduling of periodic, real-time tasks

Cited by 864 publications

References 4 publications

Static-Priority Scheduling of Sporadic Messages on a Wireless Channel

Static-Priority Scheduling of Sporadic Messages on a Wireless Channel

Periodicity of real-time schedules for dependent periodic tasks on identical multiprocessor platforms

Allocation of Parallel Real-Time Tasks in Distributed Multi-core Architectures Supported by an FTT-SE Network

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