Hybrid approach based on partitioned and global scheduling for weakly hard real-time tasks

Ismail, Habibah

Hybrid approach based on partitioned and global scheduling for weakly hard real-time tasks

dc.contributor.author	Ismail, Habibah
dc.date.accessioned	2024-01-15T04:47:59Z
dc.date.available	2024-01-15T04:47:59Z
dc.date.issued	2019
dc.description	Thesis (PhD. (Computer Science))
dc.description.abstract	Real-time systems can be classified into three categories, based on the "seriousness" of deadline misses either by hard, soft or weakly hard real-time tasks. Real-time scheduling algorithms proposed for use, have the ability to guarantee a bounded allowance of deadline misses in predictable way dedicated to weakly hard realtime tasks. Studies have shown that previous researches for multiprocessor scheduling of weakly hard real-time tasks using non-optimal heuristics wherein cannot guarantee that an allocation of all tasks can be feasibly scheduled. Moreover, the use of hierarchical scheduling algorithm under PFair algorithm may cause high scheduling overhead due to frequent preemptions and migrations. This research is done to address the problem of optimization in partitioned scheduling and task migration in global scheduling that causes scheduling overheads. Therefore, to achieve that, the partitioned scheduling approach, R-BOUND-MP with next-fit-ring noscaling (R-BOUND-MP-NFRNS) and the global scheduling approach, multiprocessor response time analysis combining with hyperperiod analysis and deadline models were proposed. Upon comparison between R-BOUND-MP and multiprocessor response time analysis with GMRTS-MK and EMRTS-MK that used PFair, it was found that R-BOUND-MP and multiprocessor response time analysis have minimized overhead than GMRTS-MK and EMRTS-MK. Furthermore, this study proposes hybrid scheduling that uses the best algorithm of each of partitioning and global approaches, R-BOUND-MP-NFRNS and RM-US (m/3m-2) with multiprocessor response time test. Based on the simulation results, the proposed hybrid scheduling approach versus R-BOUND-MP-NFRNS, the deadline satisfaction ratio improves by 2.5%. In the proposed approach versus multiprocessor response time, the deadline satisfaction ratio has improved by 5%. The overhead ratio for the proposed hybrid approach versus R-BOUND-MP-NFRNS has reduced by 5% and the proposed hybrid approach versus multiprocessor response time reduces by 7%. According to the result, the proposed hybrid approach achieved higher percentage in ratio of deadline satisfaction and minimized its overhead percentage compared to the other approaches.
dc.description.sponsorship	Faculty of Engineering - School of Computing
dc.identifier.uri	http://openscience.utm.my/handle/123456789/961
dc.language.iso	en
dc.publisher	Universiti Teknologi Malaysia
dc.subject	Real-time clocks (Computers)
dc.subject	Multiprocessors—Programming
dc.subject	Computer scheduling
dc.title	Hybrid approach based on partitioned and global scheduling for weakly hard real-time tasks
dc.type	Thesis
dc.type	Dataset