Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment
Journal of the ACM (JACM)
Formal requirements for virtualizable third generation architectures
Communications of the ACM
An Open Real-Time Environment for Parallel and Distributed Systems
ICDCS '00 Proceedings of the The 20th International Conference on Distributed Computing Systems ( ICDCS 2000)
Rate Monotonic Analysis: The Hyperbolic Bound
IEEE Transactions on Computers
A new approach for distributed computing in avionics systems
ISICT '03 Proceedings of the 1st international symposium on Information and communication technologies
An Integrated Architecture for Future Car Generations
ISORC '05 Proceedings of the Eighth IEEE International Symposium on Object-Oriented Real-Time Distributed Computing
Hierarchical Fixed Priority Pre-Emptive Scheduling
RTSS '05 Proceedings of the 26th IEEE International Real-Time Systems Symposium
Challenges in automotive software engineering
Proceedings of the 28th international conference on Software engineering
SIRAP: a synchronization protocol for hierarchical resource sharingin real-time open systems
EMSOFT '07 Proceedings of the 7th ACM & IEEE international conference on Embedded software
Analysis of Hierarchical EDF Pre-emptive Scheduling
RTSS '07 Proceedings of the 28th IEEE International Real-Time Systems Symposium
The definitive guide to the xen hypervisor
The definitive guide to the xen hypervisor
A Hierarchical Framework for Component-based Real-time Systems
Electronic Notes in Theoretical Computer Science (ENTCS)
RTSS'10 Proceedings of the 21st IEEE conference on Real-time systems symposium
| Hi-index | 0.01 |
The computational power of embedded systems have increased steadily during the recent years. In contrast to former approaches which allowed at least one application per computational node the memory size and computational power of today allows to host more than one application per node. Often applications are delivered by suppliers as a whole including the operating systems where the application tasks run on top. In this case virtualization is a common software approach to maintain isolation between different applications on the same computation system. Virtual machine monitors are able to divide the resources of a physical system into several logical subsystems. However, those monitors which are available today do not focus on the preservation of real-time properties. Consequently, our working group develops and investigates a two-level hierarchy of real-time schedulers, where a global scheduler assigns temporal resources to guest systems, while each subsystem has its own local scheduler for its application tasks. In this contribution, we focus on a formal investigation of the real-time properties of the two-level scheduling hierarchy. The starting points are independent applications building subsystems, each containing a set of tasks and a local scheduler, which have to be integrated and configured at the global scheduling level. Utilization bounds are derived unfolding the overhead of such an approach. Furthermore we propose systematic process for the computation of the task parameters for both levels of scheduling. Representatively the whole approach is applied to the rate monotonic assignment of priorities to tasks at the low scheduling level. For reasons of abstraction all these tasks are mapped into a single task proxy. This enables the global scheduler to treat all of its subsystems as periodic tasks allowing again for the application of the rate monotonic assignment of priorities to tasks.