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Efficient Guaranteed Disk Request Scheduling with Fahrrad
, 2008
"... Guaranteed I/O performance is needed for a variety of applications ranging from real-time data collection to desktop multimedia to large-scale scientific simulations. Reservations on throughput, the standard measure of disk performance, fail to effectively manage disk performance due to the orders o ..."
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Cited by 33 (10 self)
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Guaranteed I/O performance is needed for a variety of applications ranging from real-time data collection to desktop multimedia to large-scale scientific simulations. Reservations on throughput, the standard measure of disk performance, fail to effectively manage disk performance due to the orders of magnitude difference between best-, average-, and worst-case response times, allowing reservation of less than 0.01 % of the achievable bandwidth. We show that by reserving disk resources in terms of utilization it is possible to create a disk scheduler that supports reservation of nearly 100 % of the disk resources, provides arbitrarily hard or soft guarantees depending upon application needs, and yields efficiency as good or better than best-effort disk schedulers tuned for performance. We present the architecture of our scheduler, prove the correctness of its algorithms, and provide results demonstrating its effectiveness.
Utilization based spare capacity distribution
- University of York, Department of Computer Science
, 2008
"... Flexible real-time applications have predefined temporal limits within which they can operate. Real-time systems that support flexible scheduling need a mechanism to distribute spare capacity in a predictable way among the running applications with respect to the applications’ temporal limits and av ..."
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Cited by 2 (1 self)
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Flexible real-time applications have predefined temporal limits within which they can operate. Real-time systems that support flexible scheduling need a mechanism to distribute spare capacity in a predictable way among the running applications with respect to the applications’ temporal limits and available system resources. This paper introduces a greedy algorithm for spare capacity distribution in flexible real-time systems to increase resource utilization during run-time. The efficiency of the proposed algorithm is evaluated by empirical tests. Additionally, performance measurements were carried out on embedded hardware to draw conclusions about the applicability of the proposed algorithm in real applications. 1.
Spare capacity distribution using exact response-time analysis
- In 17th International Conference on Real-Time and Network Systems
, 2009
"... Real-time systems designed for use in dynamic open environments allow applications to enter and leave the system during runtime. This leads to changing runtime scenarios where the load and the spare capacity of hardware resources is influenced by the resource demand of running applications. Flexible ..."
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Cited by 1 (1 self)
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Real-time systems designed for use in dynamic open environments allow applications to enter and leave the system during runtime. This leads to changing runtime scenarios where the load and the spare capacity of hardware resources is influenced by the resource demand of running applications. Flexible real-time application components, with variable temporal parameters, can adapt their timing behaviour to these changing runtime scenarios and improve both, their Quality of Service (QoS) and the utilisation of system resources. In these open systems application components are often designed independently of each other, introducing the need for system management of resources at runtime. This management requires a mechanism to distribute the available system resources among the running application components, in a way that maximises resource usage and increases QoS with respect to their importance and temporal limits. This paper introduces a runtime algorithm for the distribution of spare capacity in flexible real-time systems. The efficiency of the presented algorithm is evaluated by empirical tests and performance measurements on embedded hardware. 1.
applications with QoS requirements on Grid
"... An architectural approach to the management of applications with QoS requirements on Grid by ..."
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An architectural approach to the management of applications with QoS requirements on Grid by
Chapter 1 Trustworthy Real-Time Systems
"... Abstract Embedded systems have experienced a dramatic increase in ubiquity and functionality. They have penetrated our life to a degree where we rely heavily on them and at the same time entrust them with vast amounts of personal information. The trust placed in them does not necessarily mean they a ..."
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Abstract Embedded systems have experienced a dramatic increase in ubiquity and functionality. They have penetrated our life to a degree where we rely heavily on them and at the same time entrust them with vast amounts of personal information. The trust placed in them does not necessarily mean they are trustworthy. Within this chapter we summarise past research of the ERTOS group at NICTA in the area and provide the initial reasoning which motivated that research. Topics covered are a secure kernel design and the design and verification of this kernel design, as well as work on scheduling and WCET analysis. 1.1
