| ¡¡ | Chinese Journal of Computers Full Text |
| Title | Leakage-Aware Energy-Efficient Scheduling for Fixed-Priority Tasks with Preemption Thresholds |
| Authors | HE Xiao-Chuan JIA Yan |
| Address | (Institute of Network Technology and Information Security, School of Computer, National University of Defense Technology, Changsha 410073) |
| Year | 2008 |
| Issue | No.11(2060¡ª2071) |
| Abstract & Background | Abstract Dynamic Voltage Scaling (DVS), which adjusts the clock speed and supply voltage dynamically, is an effective technique in reducing the energy consumption of embedded real-time systems. However, the longer a job is executed, the more energy in the leakage current the device/processor consumes for the job. Procrastination scheduling, where task execution can be delayed to maximize the duration of idle intervals by keeping the processor in a sleep/shutdown state even if there are pending tasks within the timing constraints imposed by performance requirements, has been proposed to minimize leakage energy drain. This paper targets energy-efficient fixed-priority with preemption threshold scheduling for periodic real-time tasks on a uni-processor DVS system with non-negligible leakage power consumption. A two-phase algorithm is proposed. In the first phase, the execution speed, i.e., the supply voltage of each task are determined by applying off-line algorithms, and in the second phase, the procrastination length of each task is derived by applying on-line simulated work-demand time analysis, and thus the time moment to turn on/off the system is determined on the fly. A series of simulation experiments was evaluated for the performance of our algorithms. The results show that the proposed algorithms can derive energy-efficient schedules. Keywords Dynamic Voltage Scaling (DVS); Fixed Priority with Preemption Threshold (FPPT); procrastination scheduling; preemption threshold assignment; real-time system |