Dynamic low-power reconfiguration of real-time systems with periodic and probabilistic tasks

This paper deals with the dynamic low-power reconfiguration of a real-time system. It processes periodic and probabilistic tasks that have hard/soft deadlines corresponding to internal/external events. A runtime event-based reconfiguration scenario is a dynamic operation allowing the addition/removal of the assumed periodic/probabilistic tasks. Thereafter, some tasks may miss their hard deadlines and the power consumption may increase. In order to reconfigure the system to be feasible, i.e., satisfying its real-time constraints with low-power consumption, this research presents a software-agent-based architecture. An intelligent agent is developed, which provides four solutions to reconfigure the system at runtime. For these solutions, in order to reconfigure the probabilistic tasks to be feasible, the agent modifies their temporal parameters dynamically; moreover, in order to feasibly serve the probabilistic tasks and reduce the system's power consumption, the agent provides three virtual processors by dynamically extending the periods of the periodic tasks. A simulation study verifies the effectiveness of the agent. Note to Practitioners - This study addresses new challenges in the real-time industrial systems by proposing original solutions for their low-power reconfiguration. This contribution is significant for future generations of low-power technology. A runtime event-based reconfiguration scenario is technically defined as any operation that works by adding/removing tasks. An agent-based architecture is developed, where an intelligent software agent is implemented to check the system's runtime evolution. The agent presents useful technical solutions to reconfigure the system in order to meet the temporal constraints of the tasks and satisfy the system's low-power consumption. It can also be deployed in reconfigurable real-time embedded systems such as lap-tops, mobile phones, and personal digital assistants.