The Deferrable Server Algorithm for Enhanced Aperiodic Responsiveness in Hard Real-Time Environments
IEEE Transactions on Computers
Fixed-priority scheduling of real-time systems using utilization bounds
Journal of Systems and Software
A Multiframe Model for Real-Time Tasks
IEEE Transactions on Software Engineering
Minimum Achievable Utilization for Fault-Tolerant Processing of Periodic Tasks
IEEE Transactions on Computers
Introduction to algorithms
RAP: A Real-Time Communication Architecture for Large-Scale Wireless Sensor Networks
RTAS '02 Proceedings of the Eighth IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS'02)
A Better Polynomial-Time Schedulability Test for Real-Time Multiframe Tasks
RTSS '98 Proceedings of the IEEE Real-Time Systems Symposium
Lifetime Behavior and its Impact on Web Caching
WIAPP '99 Proceedings of the 1999 IEEE Workshop on Internet Applications
A Hyperbolic Bound for the Rate Monotonic Algorithm
ECRTS '01 Proceedings of the 13th Euromicro Conference on Real-Time Systems
Schedulability Analysis and Utilization Bounds for Highly Scalable Real-Time Services
RTAS '01 Proceedings of the Seventh Real-Time Technology and Applications Symposium (RTAS '01)
Aperiodic Servers with Resource Constraints
RTSS '01 Proceedings of the 22nd IEEE Real-Time Systems Symposium
A Utilization Bound for Aperiodic Tasks and Priority Driven Scheduling
IEEE Transactions on Computers
A Feasible Region for Meeting Aperiodic End-to-End Deadlines in Resource Pipelines
ICDCS '04 Proceedings of the 24th International Conference on Distributed Computing Systems (ICDCS'04)
Exact Admission-Control for Integrated Aperiodic and Periodic Tasks
RTAS '05 Proceedings of the 11th IEEE Real Time on Embedded Technology and Applications Symposium
On Schedulability Bounds of Static Priority Schedulers
RTAS '05 Proceedings of the 11th IEEE Real Time on Embedded Technology and Applications Symposium
Modeling 3-Tiered Web Applications
MASCOTS '05 Proceedings of the 13th IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems
On Non-Utilization Bounds for Arbitrary Fixed Priority Policies
RTAS '06 Proceedings of the 12th IEEE Real-Time and Embedded Technology and Applications Symposium
Hi-index | 0.00 |
Prior research on schedulability bounds focused primarily on bounding utilization/ as a means to meet deadline constraints. Nontrivial bounds were found for a handful of scheduling policies in which utilization is directly related to the ability of the policy to meet deadlines. Examples include rate-monotonic, deadline-monotonic, and EDF scheduling. For most other scheduling policies, however, utilization is not correlated with schedulability. For example, shortest-job-first can miss deadlines at an arbitrarily low utilization. This raises the question of whether or not some other nonutilization-based metric might be more indicative of schedulability in those cases. This article answers the above question positively by extending the notion of schedulability bounds, in a uniform manner, to arbitrary (fixed) priorities and nonutilization metrics. We present a simple function that generates the schedulability metric to be bounded from the definition of a fixed-priority scheduling policy, and derive a nontrivial schedulability bound on that metric for aperiodic tasks. It is shown that the generated metrics and bounds are valid in that no deadline misses occur when these bounds are not violated. This result allows efficient real-time admission control to be performed in systems with arbitrary fixed-priority scheduling policies. As an example, we illustrate applying schedulability bounds for admission control to shortest-job-first and velocity-monotonic scheduling. While the proposed nonutilization bounds and feasible regions are derived for fixed-priority scheduling policies, the authors are investigating extensions of the results to dynamic-priority scheduling.