Federated Scheduling of Sporadic DAGs on Unrelated Multiprocessors

2021 ◽  
Vol 20 (5s) ◽  
pp. 1-25
Author(s):  
Petros Voudouris ◽  
Per Stenström ◽  
Risat Pathan
Keyword(s):  
Scheduling Algorithm ◽  
Empirical Evaluation ◽  
Schedulability Analysis ◽  
Task Assignment ◽  
Global Work ◽  
Heterogeneous Multiprocessor

This paper presents a federated scheduling algorithm for implicit-deadline sporadic DAGs that execute on an unrelated heterogeneous multiprocessor platform. We consider a global work-conserving scheduler to execute a single DAG exclusively on a subset of the unrelated processors. Formal schedulability analysis to find the makespan of a DAG on its dedicated subset of the processors is proposed. The problem of determining each subset of dedicated unrelated processors for each DAG such that the DAG meets its deadline (i.e., designing the federated scheduling algorithm) is tackled by proposing a novel processors-to-task assignment heuristic using a new concept called processor value . Empirical evaluation is presented to show the effectiveness of our approach.

scholarly journals Limited Non-Preemptive EDF Scheduling for a Real-Time System with Symmetry Multiprocessors

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 172 ◽  
Author(s):  
Hoyoun Lee ◽  
Jinkyu Lee
Keyword(s):  
Real Time ◽  
Scheduling Algorithm ◽  
Schedulability Analysis ◽  
Timing Constraints ◽  
Limited Information ◽  
Time System ◽  
Real Time System ◽  
System A ◽  
The Future ◽  
Earliest Deadline

In a real-time system, a series of jobs invoked by each task should finish its execution before its deadline, and EDF (Earliest Deadline First) is one of the most popular scheduling algorithms to meet such timing constraints of a set of given tasks. However, EDF is known to be ineffective in meeting timing constraints for non-preemptive tasks (which disallow any preemption) when the system does not know the future job release patterns of the tasks. In this paper, we develop a scheduling algorithm for a real-time system with a symmetry multiprocessor platform, which requires only limited information about the future job release patterns of a set of non-preemptive tasks, called LCEDF. We then derive its schedulability analysis that provides timing guarantees of the non-preemptive task set on a symmetry multiprocessor platform. Via simulations, we demonstrate the proposed schedulability analysis for LCEDF significantly improves the schedulability performance in meeting timing constraints of a set of non-preemptive tasks up to 20.16%, compared to vanilla non-preemptive EDF.

CQPSO scheduling algorithm for heterogeneous multi-core DAG task model

2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740050 ◽  
Author(s):  
Wenzheng Zhai ◽  
Yue-Li Hu ◽  
Feng Ran
Keyword(s):  
Task Scheduling ◽  
High Performance ◽  
Directed Acyclic Graph ◽  
Scheduling Algorithm ◽  
Task Assignment ◽  
Distributed Environment ◽  
Computing Environment ◽  
Task Model ◽  
Scheduling Method ◽  
Earliest Finish Time

Efficient task scheduling is critical to achieve high performance in a heterogeneous multi-core computing environment. The paper focuses on the heterogeneous multi-core directed acyclic graph (DAG) task model and proposes a novel task scheduling method based on an improved chaotic quantum-behaved particle swarm optimization (CQPSO) algorithm. A task priority scheduling list was built. A processor with minimum cumulative earliest finish time (EFT) was acted as the object of the first task assignment. The task precedence relationships were satisfied and the total execution time of all tasks was minimized. The experimental results show that the proposed algorithm has the advantage of optimization abilities, simple and feasible, fast convergence, and can be applied to the task scheduling optimization for other heterogeneous and distributed environment.

scholarly journals A WEAKLY HARD SCHEDULING APPROACH OF PARTITIONED SCHEDULING ON MULTIPROCESSOR SYSTEMS

2015 ◽  
Vol 77 (9) ◽  
Author(s):  
Habibah Ismail ◽  
Dayang N. A. Jawawi
Keyword(s):  
Real Time ◽  
Bin Packing ◽  
Scheduling Algorithm ◽  
Schedulability Analysis ◽  
Packing Problem ◽  
Multiprocessor Scheduling ◽  
Time Task ◽  
Application Systems ◽  
Hard Constraints ◽  
Hard Real Time

Real-time systems or tasks can be classified into three categories, based on the “seriousness” of deadline misses – hard, soft and weakly hard real-time tasks. The consequences of a deadline miss of a hard real-time task can be prohibitively expensive because all the tasks must meet their deadlines whereas soft real-time tasks tolerate “some” deadline misses. Meanwhile, in a weakly hard real-time task, the distribution of its met and missed deadlines is stated and specified precisely.  As real-time application systems increasingly come to be implemented upon multiprocessor environments, thus, this study applies multiprocessor scheduling approach for verification of weakly hard real-time tasks and to guaranteeing the timing requirements of the tasks. In fact, within the multiprocessor, the task allocation problem seem even harder than in uniprocessor case; thus, in order to cater that problem, the sufficient and efficient scheduling algorithm supported by accurate schedulability analysis technique is present to provide weakly hard real-time guarantees. In this paper, a weakly hard scheduling approach has been proposed and schedulability analysis of proposed approach consists of the partitioned multiprocessor scheduling techniques with solutions for the bin-packing problem, called R-BOUND-MP-NFRNS (R-BOUND-MP with next-fit-ring noscaling) combining with the exact analysis, named hyperperiod analysis and deadline models; weakly hard constraints and µ-pattern under static priority scheduling. Then, Matlab simulation tool is used in order to validate the result of analysis. From the evaluation results, it can be proven that the proposed approach outperforms the existing approaches in terms of satisfaction of the tasks deadlines. 

Process Scheduling in Heterogeneous Multiprocessor Systems Using Task Duplication

2010 ◽  
Vol 6 (1) ◽  
pp. 58-69 ◽  
Author(s):  
Pranay Chaudhuri ◽  
Jeffrey Elcock
Keyword(s):  
Critical Path ◽  
Scheduling Algorithm ◽  
Multiprocessor System ◽  
Process Scheduling ◽  
Algorithm Selection ◽  
Alternative Scheduling ◽  
Selection Policy ◽  
Task Duplication ◽  
Earliest Finish Time ◽  
Heterogeneous Multiprocessor

Scheduling tasks in heterogeneous parallel and distributed computing environments continues to be a challenging problem. In this paper, the authors investigate the Heterogeneous Earliest Finish Time (HEFT) algorithm, along with alternative scheduling policies for task prioritising phases and the Critical Path on a Processor (CPOP) for scheduling tasks on a heterogeneous multiprocessor system. The authors show that by combining the HEFT algorithm selection policy with the task duplication strategy, it is possible to further reduce the schedule length produced by both HEFT and CPOP. The process scheduling algorithm presented in this paper compares favourably with other algorithms that use a similar strategy. The proposed algorithm has a time complexity of ?(¦V¦2(p + d)), whererepresents the number of tasks, p represents the number of processors and d the maximum in-degree of tasks.

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