TL plane-based real-time scheduling for homogeneous multiprocessors
We consider optimal real-time scheduling of periodic tasks on multiprocessorsi.e.,satisfying all task deadlines, when the total utilization demand does not exceed the utilization capacity of the processors. We introduce a novel abstraction for reasoning about task execution behavior on multiprocessors, called TL plane and present TL plane-based real-time scheduling algorithms. We show that scheduling for multiprocessors can be viewed as scheduling on repeatedly occurring TL planes, and feasibly scheduling on a single TL plane results in an optimal schedule. Within a single TL plane, we analytically show a sufficient condition to provide a feasible schedule. Based on these, we provide two examples of TL plane-based real-time scheduling algorithms, including non-work-conserving and work-conserving approaches. Further, we establish that the algorithms have bounded overhead. Our simulation results validate our analysis of the algorithm overhead. In addition, we experimentally show that our approaches have a reduced number of task migrations among processors when compared with a previous algorithm.
real-time scheduling optimality multiprocessor systems