scholarly journals Towards Fully Jitterless Applications: Periodic Scheduling in Multiprocessor MCSs Using a Table-Driven Approach

2020 ◽  
Vol 10 (19) ◽  
pp. 6702
Author(s):  
Eugenia Ana Capota ◽  
Cristina Sorina Stangaciu ◽  
Mihai Victor Micea ◽  
Daniel-Ioan Curiac
Keyword(s):  
Real Time ◽  
Multiprocessor Systems ◽  
Preemptive Scheduling ◽  
Algorithm Performance ◽  
Safety Critical ◽  
Time Table ◽  
Scheduling Method ◽  
Embedded Applications ◽  
Special Case ◽  
Mixed Criticality

In mixed criticality systems (MCSs), the time-triggered scheduling approach focuses on a special case of safety-critical embedded applications which run in a time-triggered environment. Sometimes, for these types of MCSs, perfectly periodical (i.e., jitterless) scheduling for certain critical tasks is needed. In this paper, we propose FENP_MC (Fixed Execution Non-Preemptive Mixed Criticality), a real-time, table-driven, non-preemptive scheduling method specifically adapted to mixed criticality systems which guarantees jitterless execution in a mixed criticality time-triggered environment. We also provide a multiprocessor version, namely, P_FENP_MC (Partitioned Fixed Execution Non-Preemptive Mixed Criticality), using a partitioning heuristic. Feasibility tests are proposed for both uniprocessor and homogenous multiprocessor systems. An analysis of the algorithm performance is presented in terms of success ratio and scheduling jitter by comparing it against a time-triggered and an event-driven method in a non-preemptive context.

Non-Preemptive Scheduling for Mixed-Criticality Real-Time Multiprocessor Systems

2018 ◽  
Vol 29 (8) ◽  
pp. 1766-1779 ◽  
Author(s):  
Hyeongboo Baek ◽  
Namyong Jung ◽  
Hoon Sung Chwa ◽  
Insik Shin ◽  
Jinkyu Lee
Keyword(s):  
Real Time ◽  
Multiprocessor Systems ◽  
Preemptive Scheduling ◽  
Mixed Criticality

Preemptive Scheduling of Real-Time Tasks on Multiprocessor Systems

1970 ◽  
Vol 17 (2) ◽  
pp. 324-338 ◽  
Author(s):  
R. R. Muntz ◽  
E. G. Coffman
Keyword(s):  
Real Time ◽  
Multiprocessor Systems ◽  
Preemptive Scheduling

scholarly journals ACO Based Scheduling Method for Soft RTOS with Simulation and Mathematical Proofs

2019 ◽  
Vol 8 (12) ◽  
pp. 4736-4740
Keyword(s):  
Real Time ◽  
Dynamic Scheduling ◽  
Mathematical Proof ◽  
Scheduling Algorithm ◽  
Algorithm Performance ◽  
Task Set ◽  
Mathematical Proofs ◽  
Scheduling Method ◽  
Time Systems ◽  
Earliest Deadline

The Ant Colony Optimization (ACO) algorithm is a mathematical model enlivened by the system searching conduct of ants. By taking a gander at the qualities of ACO, it is most suitable for scheduling of tasks in soft real-time systems. In this paper, the ACO based scheduling method for the soft real-time operating system (RTOS) has been profound with mathematical and practical proof. In Mathematical proof, three different Propositions and two Theorems have been given, which prove the correctness of the proposed algorithm. Practical experiments also support mathematical proofs. During the investigation, observations are gathered with different periodic task set. Algorithms have been observed regarding Success Ratio (SR) and Effective CPU utilization (ECU). ACO based scheduling algorithm has been compared with the Earliest Deadline First (EDF) algorithm with parameter SR and ECU. The EDF is dynamic scheduling algorithm and it is most suitable in RTOS when task set is preemptable. It is noted that the new algorithm is equally efficient during under loaded conditions when CPU load is less than one. ACO based scheduling algorithm performs superior during the overloaded conditions when CPU load is more than one where as EDF algorithm performance degraded in overload condition. Empirical study has been executed with a hefty Dataset consist of more than 7500 task set, and a set contains different one to nine processes where CPU load is dynamic for each process set and differ from 0.5 to 5. Algorithms have been executed on five-hundred-time unit for each process set to authenticate the accuracy of both algorithms.

scholarly journals Contention-Free Scheduling for Mixed-Criticality Multiprocessor Real-Time System

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1515
Author(s):  
Hyeongboo Baek ◽  
Kilho Lee
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Multiprocessor Systems ◽  
Real Time Systems ◽  
Time System ◽  
Real Time System ◽  
Scheduling Policy ◽  
And Performance ◽  
Time Systems ◽  
Mixed Criticality

Zero-laxity (ZL) and contention-free (CF) policies have received considerable attention owing to their simplicity and applicability to real-time systems equipped with symmetry multiprocessors. Recently, the ZL policy for mixed-criticality (MC) systems has been proposed and studied, but the applicability to and performance of the CF policy for MC systems have not been investigated yet. In this paper, we propose the CF policy (as a scheduling policy) for MC symmetry multiprocessor systems, referred to as the MC systems tailored CF policy (MC-CF), and a schedulability analysis in support thereof. We define the notion of contention-free slots for two different criticalities (of MC systems) of tasks, propose a technique to limit the amount to be utilized for each task by defining an upper bound, and subsequently explain the way in which the contention-free slots are systematically utilized to improve the schedulability of MC symmetry multiprocessor systems. Following this, we develop a deadline analysis (DA) for MC-CF. Using our experimental results under various environmental settings, we demonstrate that MC-CF can significantly improve the schedulability of fixed-priority scheduling.

Efficient Scheduling Algorithm for Hard Real-Time Tasks in Primary-Backup Based Multiprocessor Systems

2009 ◽  
Vol 20 (10) ◽  
pp. 2628-2636 ◽  
Author(s):  
Jian WANG ◽  
Jian-Ling SUN ◽  
Xin-Yu WANG ◽  
Shen-Kang WANG ◽  
Jun-Bo CHEN
Keyword(s):  
Real Time ◽  
Scheduling Algorithm ◽  
Multiprocessor Systems ◽  
Hard Real Time
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