Schedulability Analysis of Mixed-Criticality Systems on Multiprocessors

Pathan, Risat Mahmud

doi:10.1109/ecrts.2012.29

Cited by 56 publications

(43 citation statements)

References 25 publications

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“…Pathan (2012) instead combined ideas from fixed-priority response-time analysis for uniprocessor mixed-criticality scheduling with regular response-time analysis for fixed-priority multiprocessor scheduling.…”

Section: Related Workmentioning

confidence: 99%

Bounding and shaping the demand of generalized mixed-criticality sporadic task systems

Ekberg¹,

Yi²

2013

Real-Time Syst

132

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We generalize the commonly used mixed-criticality sporadic task model to let all task parameters (execution-time, deadline and period) change between criticality modes. In addition, new tasks may be added in higher criticality modes and the modes may be arranged using any directed acyclic graph, where the nodes represent the different criticality modes and the edges the possible mode switches. We formulate demand bound functions for mixed-criticality sporadic tasks and use these to determine EDF-schedulability. Tasks have different demand bound functions for each criticality mode. We show how to shift execution demand between different criticality modes by tuning the relative deadlines. This allows us to shape the demand characteristics of each task. We propose efficient algorithms for tuning all relative deadlines of a task set in order to shape the total demand to the available supply of the computing platform. Experiments indicate that this approach is successful in practice. This new approach has the added benefit of supporting hierarchical scheduling frameworks.

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Section: Related Workmentioning

confidence: 99%

Bounding and shaping the demand of generalized mixed-criticality sporadic task systems

Ekberg¹,

Yi²

2013

Real-Time Syst

132

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“…Several multiprocessor mixed-criticality scheduling algorithms have already been developed [8]- [11], [22]- [25], including both global and partitioned approaches. For instance, Pathan [22] derived a sufficient schedulability condition of a global fixed-priority scheduling algorithm on preemptive multiprocessors based on response time analysis.…”

Section: Related Workmentioning

confidence: 99%

“…For instance, Pathan [22] derived a sufficient schedulability condition of a global fixed-priority scheduling algorithm on preemptive multiprocessors based on response time analysis. Baruah et al [10] proposed global and partitioned scheduling algorithms for mixed-criticality implicit-deadline sporadic task systems by combining fpEDF [23] with EDF-VD, and they showed that partitioned scheduling gives better system schedulability than global scheduling.…”

Section: Related Workmentioning

confidence: 99%

Mixed-Criticality Scheduling on Multiprocessors Using Task Grouping

Ren

Phan

2015

2015 27th Euromicro Conference on Real-Time Systems

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Real-time systems are increasingly running a mix of tasks with different criticality levels: for instance, unmanned aerial vehicle has multiple software functions with different safety criticality levels, but runs them on a single, shared computational platform. In addition, these systems are increasingly deployed on multiprocessor platforms because this can help to reduce their cost, space, weight, and power consumption. To assure the safety of such systems, several mixed-criticality scheduling algorithms have been developed that can provide mixed-criticality timing guarantees. However, most existing algorithms have two important limitations: they do not guarantee strong isolation among the high-criticality tasks, and they offer poor realtime performance for the low-criticality tasks. Abstract-Real-time systems are increasingly running a mix of tasks with different criticality levels: for instance, unmanned aerial vehicle has multiple software functions with different safety criticality levels, but runs them on a single, shared computational platform. In addition, these systems are increasingly deployed on multiprocessor platforms because this can help to reduce their cost, space, weight, and power consumption. To assure the safety of such systems, several mixed-criticality scheduling algorithms have been developed that can provide mixed-criticality timing guarantees. However, most existing algorithms have two important limitations: they do not guarantee strong isolation among the high-criticality tasks, and they offer poor real-time performance for the low-criticality tasks. Disciplines Computer Engineering | Computer SciencesIn this paper, we present a partitioned scheduling scheme for mixed-criticality tasks on multiprocessor platforms that addresses both issues. Our scheduling scheme consists of (i) a task-toprocessor packing algorithm that takes into account the demands of tasks with respect to their criticality levels, and (ii) a mixedcriticality uniprocessor scheduling strategy that is based on task grouping. Our strategy associates each high-criticality task with a subset of the low-criticality tasks and encapsulates them in a task group, which is scheduled with the other task groups under the Earliest Deadline First (EDF) policy. Within each task group, the low-criticality task and the high-criticality tasks are scheduled using a server-based strategy, so as to enable more of the former to meet their deadlines without affecting the latter. We present a schedulability analysis for our scheduling strategy, and we show how tasks can be grouped using Mixed Integer Nonlinear Programming. Our evaluation shows that our proposed scheme significantly outperforms existing partitioned mixed-criticality scheduling algorithms, in terms of both the fraction of schedulable task sets and its ability to schedule low-criticality tasks.

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“…Since then several pieces of work in the field have been focusing on deriving scheduling strategies with a good average behaviour either on uniprocessors [9], [10], [11], [12], [13], [14], [15], [16], [17], [18] or, more recently, considering multiprocessor platforms [19], [20], [19], [21], [22]. The reader may refer to [1] for a good source of information about recent developments in the area.…”

Section: Related Workmentioning

confidence: 99%

Considerations on the Least Upper Bound for Mixed-Criticality Real-Time Systems

Santos

Lima

Bletsas

2015

2015 Brazilian Symposium on Computing Systems Engineering (SBESC)

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Real-time mixed-criticality systems (MCS) are designed so that tasks with different criticality levels share the same computing platform. Scheduling mechanisms must ensure that high criticality tasks are safe independently of lower criticality tasks' behaviour. In this paper we provide theoretical schedulability properties for MCS by showing that: (a) the least upper bound on processor utilisation of MCS is in general null for both uniprocessor and multiprocessor platforms; (b) this bound lies in interval [ln 2, 2(√2−1)] if higher criticality tasks do not have periods larger than lower criticality ones; and (c) if the task of these uniprocessor systems have harmonic periods, the least upper bound reaches 1. Considerations on the Least Upper Bound forMixed-Criticality Real-Time Systems Abstract-Real-time mixed-criticality systems (MCS) are designed so that tasks with different criticality levels share the same computing platform. Scheduling mechanisms must ensure that high criticality tasks are safe independently of lower criticality tasks' behaviour. In this paper we provide theoretical schedulability properties for MCS by showing that: (a) the least upper bound on processor utilisation of MCS is in general null for both uniprocessor and multiprocessor platforms; (b) this bound lies in interval [ln 2, 2( √ 2 − 1)] if higher criticality tasks do not have periods larger than lower criticality ones; and (c) if the task of these uniprocessor systems have harmonic periods, the least upper bound reaches 1.

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Schedulability Analysis of Mixed-Criticality Systems on Multiprocessors

Cited by 56 publications

References 25 publications

Bounding and shaping the demand of generalized mixed-criticality sporadic task systems

Bounding and shaping the demand of generalized mixed-criticality sporadic task systems

Mixed-Criticality Scheduling on Multiprocessors Using Task Grouping

Considerations on the Least Upper Bound for Mixed-Criticality Real-Time Systems

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