  It is an increasingly important issue to reduce the energy consumption of
computing systems. In this paper, we consider partition based energy-aware
scheduling of periodic real-time tasks on multicore processors. The scheduling
exploits dynamic voltage scaling (DVS) and core sleep scheduling to reduce both
dynamic and leakage energy consumption. If the overhead of core state switching
is non-negligible, however, the performance of this scheduling strategy in
terms of energy efficiency might degrade. To achieve further energy saving, we
extend the static task scheduling with run-time task reallocation. The basic
idea is to aggregate idle time among cores so that as many cores as possible
could be put into sleep in a way that the overall energy consumption is
reduced. Simulation results show that the proposed approach results in up to
20% energy saving over traditional leakage-aware DVS.
