Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment
Journal of the ACM (JACM)
The Aperiodic Multiprocessor Utilization Bound for Liquid Tasks
RTAS '02 Proceedings of the Eighth IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS'02)
Analyzing Fixed-Priority Global Multiprocessor Scheduling
RTAS '02 Proceedings of the Eighth IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS'02)
Global Multiprocessor Scheduling of Aperiodic Tasks using Time-Independent Priorities
RTAS '03 Proceedings of the The 9th IEEE Real-Time and Embedded Technology and Applications Symposium
Global Priority-Driven Aperiodic Scheduling on Multiprocessors
IPDPS '03 Proceedings of the 17th International Symposium on Parallel and Distributed Processing
Partitioned Aperiodic Scheduling on Multiprocessors
IPDPS '03 Proceedings of the 17th International Symposium on Parallel and Distributed Processing
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)
Static-Priority Scheduling on Multiprocessors
RTSS '01 Proceedings of the 22nd IEEE Real-Time Systems Symposium
A survey of hard real-time scheduling for multiprocessor systems
ACM Computing Surveys (CSUR)
Slack-based multiprocessor scheduling of aperiodic real-time tasks
Real-Time Systems
| Hi-index | 0.00 |
We provide a constant time schedulability test for an on-line multiprocessor server handling aperiodic tasks. Dhall's effect is avoided by dividing the tasks in two priority classes based on task utilization: heavy and light. We prove that if the load on the multiprocessor server stays below U threshold = 3 驴 驴7 驴 35.425%, the server can accept an incoming aperiodic task and guarantee that the deadlines of all accepted tasks will be met. The same number 35.425% is also a threshold for a task to be characterized as heavy.The bound U threshold = 3 驴 驴7驴 35.425% is easy-to-use, but not sharp if we know the number of processors in the multiprocessor system. Assuming the server to be equipped with m processors, we calculate a formula for the sharp bound U threshold (m), which converges to U threshold from above as m 驴 驴.The results are based on a utilization function u(x) = 2(1 驴 x)/(2 + 驴2+2x). By using this function, the performance of the multiprocessor server can in some cases be improved beyond U threshold(m) by paying the extra overhead of monitoring the individual utilization of the current tasks.