  Heterogeneous multicore architectures are becoming increasingly popular due
to their potential of achieving high performance and energy efficiency compared
to the homogeneous multicore architectures. In such systems, the real-time
scheduling problem becomes more challenging in that processors have different
speeds. A job executing on a processor with speed $x$ for $t$ time units
completes $(x \cdot t)$ units of execution. Prior research on heterogeneous
multiprocessor real-time scheduling has focused on hard real-time systems,
where, significant processing capacity may have to be sacrificed in the
worst-case to ensure that all deadlines are met. As meeting hard deadlines is
overkill for many soft real-time systems in practice, this paper shows that on
soft real-time heterogeneous multiprocessors, bounded response times can be
ensured for globally-scheduled sporadic task systems with no utilization loss.
A GEDF-based scheduling algorithm, namely GEDF-H, is presented and response
time bounds are established under both preemptive and non-preemptive GEDF-H
scheduling. Extensive experiments show that the magnitude of the derived
response time bound is reasonable, often smaller than three task periods. To
the best of our knowledge, this paper is the first to show that soft real-time
sporadic task systems can be supported on heterogeneous multiprocessors without
utilization loss, and with reasonable predicted response time.
