IASA: an energy-efficient scheduling algorithm for real-time tasks with lock-free objects

In this paper, we are interested in the energy-efficient scheduling of real-time tasks which may access lock-free objects in a non-ideal DVS processor. Compared to conventional lock-based real-time synchronisation protocols, lock-free objects have the advantage of the avoidance of priority inversion and deadlock. However, because lock-free objects permit concurrent operations to interfere with each other, the access to a lock-free object might take an arbitrarily long time to complete owing to repeated interferences. In this paper, we propose an algorithm, called interference-aware speed assignment (IASA), for scheduling of real-time tasks with lock-free objects. The IASA assigns proper execution speeds to tasks scheduled by the earliest deadline first (EDF) scheduling policy. The execution speeds are calculated based on the schedulability analysis of the EDF policy with the cost of the interferences of lock-free objects. As a result, the energy consumption can be reduced while meeting the timing constraints of real-time tasks.