Skip to main content

Automatic Task Splitting for Uniprocessor Systems Scheduled with Non-Preemptive EDF | Chapter 03 | Theory and Applications of Mathematical Science Vol. 1

Although preemptive scheduling dominates non-preemptive scheduling from a schedulability perspective, the latter will often be chosen by developers of real-time systems with resource constraints due to the inherently lower system overheads, easier code implementation and timing analysis. This paper is concerned with the uniprocessor scheduling of periodic and sporadic tasks with arbitrary relative deadlines in real-time systems using the non-preemptive version of the Earliest Deadline First (npEDF) algorithm. Although npEDF is known to be optimal among the non-preemptive work-conserving schedulers, it can still be restrictive in the sense that there exists uniprocessor-feasible task sets (with arbitrarily low CPU utilization) that are not schedulable with npEDF. For such task sets, system developers are forced to either consider the use of an alternate scheduling strategy or refactor the task software in some beneficial way. One such beneficial way is to apply a concept known as ‘task splitting’. However to date, little guidance has been available to assist developers with the latter process, and it is often performed on an ad-hoc basis. This paper will propose the application of a fast and efficient task splitting technique to assist developers with this software refactoring process, which can thus be used to maximize the achievable CPU utilization whilst retaining the benefits of non-preemption. Examples and experimental results are given to illustrate the performance of the algorithm. For random but representative task sets, the results also indicate that in the average case only a relatively small number of tasks require the application of task splitting to become schedulable under npEDF.

Author(s) Details

Michael Short
School of Computing, Engineering and Digital Technologies, Teesside University, Middlesbrough, UK.

View Books: http://bp.bookpi.org/index.php/bpi/catalog/book/117

Comments

Popular posts from this blog

A Brief Study of Middleware Technologies: Programming Applications and Management Systems | Chapter 15 | Novel Research Aspects in Mathematical and Computer Science Vol. 1

  Many platforms, services, applications, hardware, and operating systems are connected through the middleware layer. Because the middleware layer abstracts much low-level complexity and makes applications and software systems portable, it allows disparate systems to interface and function together in harmony. Middleware technologies enable software engineers to swiftly construct software systems and applications, allowing developers to focus on more important tasks. This chapter examines several types of middleware systems and discusses middleware capabilities, middleware operation, middleware's function in cloud-based systems, and the best middleware platforms to use. Middleware systems are widely utilised and can be found in practically any software system or application. Middleware programmes provide as a link between many sorts of systems and protocols. They serve as a mechanism for various systems. To successfully exchange information, it runs on a variety of operating system

A Prospective Study about Safety and Efficacy of Perioperative Lidocaine Infusion | Chapter 09 | New Horizons in Medicine and Medical Research Vol. 8

 Opioids cause clinically significant side effects such as respiratory depression, immunosuppression, muscle rigidity, negative inotropism, nausea, vomiting, hyperalgesia, urine retention, postoperative ileus, and drowsiness. Perioperative opioids are a major contributor to the United States' and other countries' opioid epidemics. Non-opioid analgesics, particularly lidocaine, are becoming more common for perioperative use as a result of this. A total of 185 adult patients were randomly assigned to one of two groups: control group I (105 patients) [fentanyl group] or group ii (80 patients) [opioid-free anaesthesia group]. Lidocaine 1.5 mg/kg bolus followed by 1.5 mg/kg/h infusion intraoperatively, and 1.5-2 mg/kg/h infusion for 2-8 hours postoperatively were given to patients in both groups at anaesthetic induction. Intraoperatively, both groups received analgesic adjuvants such as diclofenac 75 mg, paracetamol 1 gm, and mgso4 30-50 mg/kg. If the mean arterial pressure (map)

Ethnopharmacological Survey among Traditional Medicine Practitioners in Abidjan (Côte d'Ivoire) for the Management of Pathologies such as Malaria, ENT Diseases, Diarrhea, Typhoid Fever and Anemia | Chapter 05 | New Horizons in Medicine and Medical Research Vol. 8

 Traditional Medicine Practitioners (TMPs) of Côte d'Ivoire are familiar with the therapeutic herbs. Medicinal plants have been shown to be useful in the treatment of common diseases such as malaria (KROA, 2004) and diabetes (N'GUESSAN et al, 2013) in several studies and scientific study. In the Abidjan District, the current policy is to integrate traditional medicine and pharmacopoeia into the national health system in order to improve population health coverage, particularly in the management of commonly encountered diseases such as malaria, ENT diseases, diarrhoea, typhoid fever, and anaemia. This research aims to increase the use of traditional medicine and pharmacopoeia in the national health system. Over the course of three months, fifty (50) PMTs in the District of Abidjan participated in this study. Plant therapists accounted for 30 of the 50 PMTs polled at the end of the study, or 60%. Traditional medicine centres use 61 types of medicinal plants from 36 famili