Schedulability Analysis and Priority Assignment for Global Job-Level Fixed-Priority Multiprocessor Scheduling

Back, Hyoungbu; Chwa, Hoon Sung; Shin, Insik

doi:10.1109/rtas.2012.33

Cited by 13 publications

(12 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, only a higher-priority task τ i can interfere with a job J q k of a lower-priority task τ k . Well-known FP scheduling algorithms include rate monotonic (RM) [13] and earliest quasi-deadline first (EQDF) [14]; a task whose T k (likewise D k − C k ) is smaller than that of other tasks has a higher priority under the RM (likewise EQDF) scheduling algorithm. We denote FP scheduling incorporating the FT policy with λ k -assignment algorithm A employing any sorting algorithm by FT-FP-A.…”

Section: Schedulability Analysis For Ft-fp-amentioning

confidence: 99%

Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors

Baek

Lee

2019

Symmetry

View full text Add to dashboard Cite

Hard real-time systems are employed in military, aeronautics, and astronautics fields where deployed systems are susceptible to software faults that can result in functional errors. Thus, there is a need to use fault-tolerant (FT) real-time scheduling. Among the various fault-tolerant real-time scheduling techniques, re-execution has been applied widely to existing real-time systems owing to its simplicity and applicability. However, re-execution requires multiple executions of every task, and some tasks miss their deadlines owing to the prolonged execution time; therefore, it has been found to be suitable for only soft real-time systems. In this paper, we propose an FT policy that can be incorporated into most (if not all) existing real-time scheduling algorithms on multiprocessor systems, which improves the reliability of the target system without a tradeoff against schedulability. As a case study, we apply the FT policy to existing fixed-priority scheduling and earliest deadline zero-laxity scheduling, and we demonstrate that it enhances reliability without schedulability loss.

show abstract

Section: Schedulability Analysis For Ft-fp-amentioning

confidence: 99%

Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors

Baek

Lee

2019

Symmetry

View full text Add to dashboard Cite

show abstract

“…SPDF scheduling is closely related to the previous work on EQDF (Earliest Quasi-Deadline First) scheduling [17]. In EQDF scheduling, each job J h i is assigned a quasi-deadline q…”

Section: System Modelmentioning

confidence: 99%

“…We first recapitulate an interference-based analysis, which has served as a basis for the schedulability conditions of various algorithms [20], [19], [7], [21], [17], [22], [13], including EDF and TFP algorithms. We also explain an existing technique, called DA-LC, which can substantially improve the performance of the interfere-based analysis.…”

Section: Spdf Schedulability Analysismentioning

confidence: 99%

“…Since it is generally intractable to compute exact I * i,k under a given scheduling algorithm, existing approaches [20], [19], [7], [21], [17], [22], [13] have derived upper-bounds on I * i,k under their target algorithms, resulting in sufficient schedulability tests.…”

Section: Spdf Schedulability Analysismentioning

confidence: 99%

“…JFP scheduling seems to offer benefits from both worlds: on account of the per-job priority, it is generally able to schedule more task sets when compared to TFP scheduling, and at the same time, it does not suffer from as many preemptions and migrations as JDP scheduling because the job priorities do not change over time. Similar to the TFP and JDP cases, many different JFP algorithms like EDF [2], EDF-US [15], fp-EDF [16], and EQDF [17], have been proposed in the past. Analysis techniques for JFP algorithms have also matured over the years starting with the utilization based tests for EDF [18] and EDF-US [15].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Extending Task-level to Job-level Fixed Priority Assignment and Schedulability Analysis Using Pseudo-deadlines

Chwa

Back

Chen

et al. 2012

2012 IEEE 33rd Real-Time Systems Symposium

Self Cite

View full text Add to dashboard Cite

In global real-time multiprocessor scheduling, a recent analysis technique for Task-level Fixed-Priority (TFP) scheduling has been shown to outperform many of the analyses for Job-level Fixed-Priority ( JFP) scheduling on average. Since JFP is a generalization of TFP scheduling, and the TFP analysis technique itself has been adapted from an earlier JFP analysis, this result is counter-intuitive and in our opinion highlights the lack of good JFP scheduling techniques. Towards generalizing the superior TFP analysis to JFP scheduling, we propose the Smallest Pseudo-Deadline First (SPDF) JFP scheduling algorithm. SPDF uses a simple task-level parameter called pseudo-deadline to prioritize jobs, and hence can behave as a TFP or JFP scheduler depending on the values of the pseudodeadlines. This natural transition from TFP to JFP scheduling has enabled us to incorporate the superior TFP analysis technique in an SPDF schedulability test. We also present a pseudo-deadline assignment algorithm for SPDF scheduling that extends the well-known Optimal Priority Assignment (OPA) algorithm for TFP scheduling. We show that our algorithm is optimal for the derived schedulability test, and also present a heuristic to overcome the computational complexity issue of the optimal algorithm. Our simulation results show that the SPDF algorithm with the new analysis significantly outperforms state-of-the-art TFP and JFP analysis. Abstract-In global real-time multiprocessor scheduling, a recent analysis technique for Task-level Fixed-Priority (TFP) scheduling has been shown to outperform many of the analyses for Job-level Fixed-Priority (JFP) scheduling on average. Since JFP is a generalization of TFP scheduling, and the TFP analysis technique itself has been adapted from an earlier JFP analysis, this result is counter-intuitive and in our opinion highlights the lack of good JFP scheduling techniques. Towards generalizing the superior TFP analysis to JFP scheduling, we propose the Smallest Pseudo-Deadline First (SPDF) JFP scheduling algorithm. SPDF uses a simple task-level parameter called pseudo-deadline to prioritize jobs, and hence can behave as a TFP or JFP scheduler depending on the values of the pseudodeadlines. This natural transition from TFP to JFP scheduling has enabled us to incorporate the superior TFP analysis technique in an SPDF schedulability test. We also present a pseudo-deadline assignment algorithm for SPDF scheduling that extends the well-known Optimal Priority Assignment (OPA) algorithm for TFP scheduling. We show that our algorithm is optimal for the derived schedulability test, and also present a heuristic to overcome the computational complexity issue of the optimal algorithm. Our simulation results show that the SPDF algorithm with the new analysis significantly outperforms state-of-the-art TFP and JFP analysis.

show abstract

A Hybrid Real-Time Scheduling Mechanism Based on Multiprocessor for Real-Time Tasks in Weakly Hard Specification

Ismail

Jawawi

Ahmedy

2022

Lecture Notes in Networks and Systems

View full text Add to dashboard Cite

Schedulability Analysis and Priority Assignment for Global Job-Level Fixed-Priority Multiprocessor Scheduling

Abstract: Unlike uniprocessor scheduling, EDF (categorized into job-level fixed-priority (JFP)

Cited by 13 publications

References 25 publications

Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors

Task-Level Re-Execution Framework for Improving Fault Tolerance on Symmetry Multiprocessors

Extending Task-level to Job-level Fixed Priority Assignment and Schedulability Analysis Using Pseudo-deadlines

A Hybrid Real-Time Scheduling Mechanism Based on Multiprocessor for Real-Time Tasks in Weakly Hard Specification

Contact Info

Product

Resources

About