COMPARISON OF BUDGET BORROWING AND BUDGET ADAPTATION IN HIERARCHICAL SCHEDULING FRAMEWORK

• Main Author: Wenkai, Wang
• Format: Others
• Language: English
• Published: Mälardalens högskola, Akademin för innovation, design och teknik 2016
• Subjects: system virtualization; CPU partition; hierarchical scheduling; monitoring; budget borrowing.
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-31091

System virtualization technology is widely used in computing nowadays. In embedded domain, it is used as a solution to resource sharing among independent applications. One of the areas is to apply virtualization technique to real-time embedded systems with timing constraints. Multi-level adaptive hierarchical scheduling (AdHierSched) framework is a virtualized real-time framework, which runs in the Linux operating system. Šis virtualized framework has ability to adapt the CPU partition sizes according to their need through monitoring their demand during run-time, which yields more appropriate processor assignment. However, the performance of the virtualized framework is still unknown when the budget borrowing mechanism is enabled. To this end, in this thesis, we explore a new direction for performing the adaptation of CPU partition. We design and implement a budget borrowing mechanism for dynamic adaptation of resource parameters in AdHierSched framework. Extensive simulations are performed in this thesis, which are used to study and compare di‚erent adaptation mechanisms with our approach. From the results of experiments, we conclude that when the framework works only with budget borrowing controller, the results are not as good as only running a budget controller in the AdHierSched framework. However, while running both of the controllers at the same time, the experiments results are good enough. We also analyze the overhead of the framework at the end of the evaluation. Finally, we conclude the thesis by presenting the possible future work.