Weakly-hard-constraintand Priority-distance Aware Partitioned Scheduling for HomogeneousMulticore Platforms

As weakly-hard real-time(WHRT) system enables to effectively exploit computing resources while guaranteeing the system stability by tolerating accidentally temporal violation,it has been broadly developed in some real-life areas over the past two decades.However,there exist rather limited studies on the scheduling of WHRT tasks upon multicores.For the existing global scheduling based schemes,the high runtime overhead caused by task migration greatly restricts their practical viability; while the current job-level partitioned algorithm usually ignores the impacts of the utilizations of tasks under weakly-hard constraints,which may significantly degrade the schedulability performance of task sets.To address such issues,with the focus global emergency-based scheduling(GEBS) for uniprocessors,two task partitioning algorithms have been proposed:the weakly-hard-constraint aware task partitioning algorithm(WHCA-TPA) and the priority-distance aware task partitioning algorithm(PDA-TPA).Firstly,WHCA-TPA considers the interference between different tasks,providing a more reasonable estimate of system utilization,and uses it to allocate tasks more reasonably.In addition,PDA-TPA aims at reducing the number of preemptions between tasks to decrease the number of context switches,thus achieving lower runtime overhead.Ultimately,when compared to the existing conventional mapping schemes,extensive experimental results show that WHCA-TPA can achieve a higher schedulability ratio under various system parameters.Meanwhile,PDA-TPA and WHCA-TPA usually has lower runtime overhead in contrast with other mapping schemes.