Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236)最新文献_第4页

Integrated dynamic scheduling of hard and QoS degradable real-time tasks in multiprocessor systems 多处理机系统中硬任务和QoS可降解实时任务的集成动态调度

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726408

Anita Mittal, G. Manimaran, C. Murthy

{"title":"Integrated dynamic scheduling of hard and QoS degradable real-time tasks in multiprocessor systems","authors":"Anita Mittal, G. Manimaran, C. Murthy","doi":"10.1109/RTCSA.1998.726408","DOIUrl":"https://doi.org/10.1109/RTCSA.1998.726408","url":null,"abstract":"Many time critical applications require predictable performance and tasks in these applications have deadlines to be met. For tasks with hard deadlines, a deadline miss can be catastrophic, while for QoS degradable tasks (soft real time tasks) timely approximate results of poorer quality or occasional deadline misses are acceptable. Imprecise computation and (m,k) firm guarantee are two workload models that quantify the trade off between schedulability and result quality. We propose dynamic scheduling algorithms for integrated scheduling of real time tasks, represented by these workload models, in multiprocessor systems. The algorithms aim at improving the schedulability of tasks by exploiting the properties of these models in QoS degradation. We also show how the proposed algorithms can be adapted for integrated scheduling of multimedia streams and hard real time tasks, and demonstrate their effectiveness in quantifying QoS degradation. Through simulation, we evaluate the performance of these algorithms using the metrics-success ratio (measure of schedulability) and quality. Our simulation results show that one of the proposed algorithms, multilevel degradation algorithm, outperforms the others in terms of both the performance metrics.","PeriodicalId":142319,"journal":{"name":"Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131419305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 27

A characterization of re-execution costs for real-time abort-oriented protocols 面向实时中止协议的重执行成本表征

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726429

Lihchyun Shu

引用次数: 5

Dual-token-based fault-tolerant scheduling for hard real-time multiprocessor systems 硬实时多处理器系统中基于双令牌的容错调度

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726423

Sungyoung Lee, S. Oh, Chul Hee Woo

{"title":"Dual-token-based fault-tolerant scheduling for hard real-time multiprocessor systems","authors":"Sungyoung Lee, S. Oh, Chul Hee Woo","doi":"10.1109/RTCSA.1998.726423","DOIUrl":"https://doi.org/10.1109/RTCSA.1998.726423","url":null,"abstract":"Real time multiprocessor systems frequently assume that there exists a dedicated processor for task allocation that never fails. This assumption is, however too strong in the sense that all the physical objects are subject to failure. Moreover once the dedicated processor fails, the whole multiprocessor system will fail. As a way to solve this problem, we propose a fault tolerant scheduling algorithm based on moving dual token. While the primary processor holding a primary token performs task allocation, the backup processor holding a backup token, in case the primary processor fails, does primary processor creation. Since no dedicated processor for task allocation exists in this scheme, failure of the whole multiprocessor system due to that of the dedicated processor can be avoided. In addition, the deadline friendly scheduling policy used for backup task allocation, compared to heuristic scheduling, allows easier implementation and improved scheduling predictability. Simulation results show that the proposed dual token based algorithm yields low rejection rates over those with dedicated processor for task allocation.","PeriodicalId":142319,"journal":{"name":"Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117235944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Multiprocessor scheduling of age constraint processes 年龄约束进程的多处理器调度

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726350

L. Lundberg

引用次数: 12

A Modified Least-Laxity-First scheduling algorithm for real-time tasks 一种改进的最小松弛优先调度算法

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726348

Sung-Heun Oh, Seung-Min Yang

引用次数: 90

Enhancing response times of end-to-end tasks using slack of local tasks 利用本地任务的空闲提高端到端任务的响应时间

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726347

Namyun Kim, Taewoong Kim, N. Chang, Heonshik Shin

引用次数: 0

Performance evaluation of on-line scheduling algorithms for imprecise computation 不精确计算下在线调度算法的性能评价

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726421

Jai-hoon Kim, Kihyun Song, Kyunghee Choi, Gihyun Jung, Seunhun Jung

引用次数: 4

Task scheduling with feedback latency for real-time control systems 实时控制系统中具有反馈延迟的任务调度

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726349

Byung Kook Kim

{"title":"Task scheduling with feedback latency for real-time control systems","authors":"Byung Kook Kim","doi":"10.1109/RTCSA.1998.726349","DOIUrl":"https://doi.org/10.1109/RTCSA.1998.726349","url":null,"abstract":"A new task-scheduling algorithm with feedback latency is suggested for real-time control systems, which considers both point of views-control theoretic and real-time computing. Building a real-time control system has two steps in general. In the controller design stage, a control performance index is defined and a controller is designed which optimizes the given performance index while maintaining stability and rejecting disturbances. In the implementation stage, a set of controllers constitutes multiple control tasks, and scheduled to run on microprocessors, which should be schedulable with limited computing resources. The author reveals that the control performance depends not only on the control period but also on the feedback latency (latency from sensing, computation to actuation), which is revealed to have more impact. We formulate a new task-scheduling problem with a suitable control performance index including the feedback latency. An iterative search algorithm is suggested which is based on feedback latency computation method. An illustrative example demonstrated the applicability of the proposed method.","PeriodicalId":142319,"journal":{"name":"Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130575695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 37

On the ability of the FDDI-M protocol to support real-time traffic 关于FDDI-M协议支持实时流量的能力

Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236) Pub Date : 1998-10-27 DOI: 10.1109/RTCSA.1998.726351

Daoxu Chen, V. Lee, E. Chan

{"title":"On the ability of the FDDI-M protocol to support real-time traffic","authors":"Daoxu Chen, V. Lee, E. Chan","doi":"10.1109/RTCSA.1998.726351","DOIUrl":"https://doi.org/10.1109/RTCSA.1998.726351","url":null,"abstract":"Timed token networks such as FDDI networks have been widely deployed to support real-time traffic such as voice and video communications. However the medium access control (MAC) protocol of FDDI allows transmission of synchronous messages up to at most one half of the total bandwidth of the network. Shin and Zheng (1995) have proposed a modification to the FDDI MAC protocol, called FDDI-M, which can double a ring's ability in supporting synchronous traffic. We compare the ability of FDDI-M to support synchronous traffic under different SBA schemes with that of FDDI. We first propose a new taxonomy of SBA schemes based on the underlying strategy used to partition the synchronous bandwidth. Next we present an analysis of the timing properties of the FDDI-M protocol, using the Worst Case Achievable Utilization (WCAU) as the performance metric. Our analytical results show that while FDDI-M improves the WCAU values under one class of SBA schemes, its performance under the other category of SBA schemes is mixed. We also perform extensive simulation to study performance of FDDI-M for MPEG video traffic, and conclude FDDI-M does outperform FDDI significantly at heavy load. The effect of SBA schemes under overload conditions is also shown to be relatively minor.","PeriodicalId":142319,"journal":{"name":"Proceedings Fifth International Conference on Real-Time Computing Systems and Applications (Cat. No.98EX236)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129630763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5