Techniques for Schedulability Analysis in Mode Change Systems under Fixed-Priority Scheduling

Huang, Wen-Hung; Chen, Jian-Jia

doi:10.1109/rtcsa.2015.36

Cited by 16 publications

(14 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, most of the existing fixed-priority scheduling results for the GMF task model assume a unique priority level per task. To the best of our knowledge, the only results that can be applied for a unique level per computation segment are the utilization-based analysis in [CHL16,HC15c].…”

Section: Incorrect Analysis Of Segmented Fixed-priority Scheduling Wimentioning

confidence: 99%

Many suspensions, many problems: a review of self-suspending tasks in real-time systems

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. In general computing systems, a job (process/task) may suspend itself whilst it is waiting for some activity to complete, e.g., an accelerator to return data. In real-time systems, such self-suspension can cause substantial performance/schedulability degradation. This observation, first made in 1988, has led to the investigation of the impact of self-suspension on timing predictability, and many relevant results have been published since. Unfortunately, as it has recently come to light, a number of the existing results are flawed. To provide a correct platform on which future research can be built, this paper reviews the state of the art in the design and analysis of scheduling algorithms and schedulability tests for self-suspending tasks in real-time systems. We provide (1) a systematic description of how self-suspending tasks can be handled in both soft and hard real-time systems; (2) an explanation of the existing misconceptions and their potential remedies; (3) an assessment of the influence of such flawed analyses on partitioned multiprocessor fixed-priority scheduling when tasks synchronize access to shared resources; and (4) a discussion of the computational complexity of analyses for different self-suspension task models.

show abstract

Section: Incorrect Analysis Of Segmented Fixed-priority Scheduling Wimentioning

confidence: 99%

Many suspensions, many problems: a review of self-suspending tasks in real-time systems

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…For the rst case, i.e., ∆ > T min i , let t * < ∆ be the arrival time of the last job in the above pattern. Lemma 2 in [16] proves that the maximum interference from 0 to t * (without the last job) is at most U max i ×t * . Therefore, by including the (last) job released at or after t * , the maximum interference incurred by τ i is at most U max i ×∆+C max i .…”

Section: Angle-synchronous Tasksmentioning

confidence: 98%

“…In the literature, such tasks are also called variable-rate-behaviour tasks [11] or multi-mode tasks [16]. Schedulability tests of such angle-synchronous tasks under FP scheduling have been proposed in [11,16].…”

Section: Angle-synchronous Tasksmentioning

confidence: 99%

“…There are two existing methods to calculate the interference due to an angle-synchronous task in an interval length ∆. One is to nd the worst-case workload by investigating the worst-case release patterns using integer linear programming (ILP) [11] or dynamic programming [16]. Another, as shown in the following lemma, is to safely approximate the interference due to an anglesynchronous task τ i by using…”

Section: Angle-synchronous Tasksmentioning

confidence: 99%

“…This is based on Theorem 1 from Davis et al [11] and Lemma 2 from Huang and Chen [16]. Without loss of generality, let the interval start from 0.…”

Section: Angle-synchronous Tasksmentioning

confidence: 99%

See 2 more Smart Citations

Parametric utilization bounds for implicit-deadline periodic tasks in automotive systems

Brüggen

Ueter

Chen

et al. 2017

Proceedings of the 25th International Conference on Real-Time Networks and Systems

Self Cite

View full text Add to dashboard Cite

Fixed-priority scheduling has been widely used in safetycritical applications. This paper explores the parametric utilization bounds for implicit-deadline periodic tasks in automotive uniprocessor systems, where the period of a task is either 1, 2, 5, 10, 20, 50, 100, 200, or 1000 milliseconds. We prove a parametric utilization bound of 90%+z for such automotive task systems under rate-monotonic preemptive scheduling (RM-P), where z is a parameter de ned by the input task set with 0 ≤ z ≤ 10%. Moreover, we explain how to perform an exact schedulability test for an automotive task set under RM-P by validating only three conditions. Furthermore, we extend our analyses to rate-monotonic non-preemptive scheduling (RM-NP). We show that very reasonable utilization values can still be achieved under RM-NP if the execution time of all tasks is below 1 millisecond. The analyses presented here are compatible with angle-synchronous tasks by applying the related arrival curves. It is shown in the evaluations that scheduling those angle-synchronous tasks according to their minimum inter-arrival time instead of assigning them to the highest priority can drastically increase the acceptance ratio in some settings.

show abstract

A survey of schedulability analysis techniques for rate-dependent tasks

Feld

Biondi

Davis

et al. 2018

Journal of Systems and Software

View full text Add to dashboard Cite

In automotive embedded real-time systems, such as the engine control unit, there are tasks that are activated whenever the crankshaft arrives at a specific angular position. As a consequence the frequency of activation changes with the crankshaft's angular speed (i.e., engine rpm). Additionally, execution times and deadlines may also depend on angular speeds and positions. This paper provides a survey on schedulability analysis techniques for tasks with this rate-dependent behaviour. It covers different task-models and analysis methods for both fixed priority and earliest deadline first scheduling. A taxonomy of the different analysis methods, classifying them according to the assumptions made and the precision of the analysis, is provided at the end of the paper

show abstract

Techniques for Schedulability Analysis in Mode Change Systems under Fixed-Priority Scheduling

Cited by 16 publications

References 22 publications

Many suspensions, many problems: a review of self-suspending tasks in real-time systems

Many suspensions, many problems: a review of self-suspending tasks in real-time systems

Parametric utilization bounds for implicit-deadline periodic tasks in automotive systems

A survey of schedulability analysis techniques for rate-dependent tasks

Contact Info

Product

Resources

About