Linux实现了实时进程的概念,但并没有提供有效的任务调度支持;另一方面,RM(Rate Monotonic)和EDF(Earliest Deadline First)等传统的优先级调度算法在实时系统中已经得到广泛应用,但它们对于确定优先级所采用的标准比较简单和片面,容易...Linux实现了实时进程的概念,但并没有提供有效的任务调度支持;另一方面,RM(Rate Monotonic)和EDF(Earliest Deadline First)等传统的优先级调度算法在实时系统中已经得到广泛应用,但它们对于确定优先级所采用的标准比较简单和片面,容易导致紧急型任务的截止期限不能被满足或系统资源不能被充分利用.文中基于RM和EDF提出了一种新的实时调度算法SBRD(Scheduler Based on Rate and Deadline),它的优先级根据重要性和紧急性两个重要因素共同确定.实验表明:与RM和EDF相比,SBRD兼具二者的优点,在保证重要任务顺利执行的前提下,优先执行紧急型任务,以满足更多任务的截止期限,更充分地利用CPU资源;与原Linux的实时调度相比,SBRD能更有效地调度实时任务.展开更多
In this paper, we describe a two-phase scheme to determine a scheduling of tasks with precedence con-straints that employ a reliability measure as one of the objectives in a Real-Time and heterogeneous distributed sys...In this paper, we describe a two-phase scheme to determine a scheduling of tasks with precedence con-straints that employ a reliability measure as one of the objectives in a Real-Time and heterogeneous distributed sys-tem. The simulation results show that, for task graphs with precedence constraints in a heterogeneous Real-Timesystem, the method performs significantly better than the two algorithms presented that do not consider reliabilitycost. Furthermore, the results suggest that higher computational heterogeneity is conducive to improving the schedu-lability of the reliability cost-driven (RCD)algorithm, while the opposite is true for the two non-RCD algorithms.展开更多
文摘Linux实现了实时进程的概念,但并没有提供有效的任务调度支持;另一方面,RM(Rate Monotonic)和EDF(Earliest Deadline First)等传统的优先级调度算法在实时系统中已经得到广泛应用,但它们对于确定优先级所采用的标准比较简单和片面,容易导致紧急型任务的截止期限不能被满足或系统资源不能被充分利用.文中基于RM和EDF提出了一种新的实时调度算法SBRD(Scheduler Based on Rate and Deadline),它的优先级根据重要性和紧急性两个重要因素共同确定.实验表明:与RM和EDF相比,SBRD兼具二者的优点,在保证重要任务顺利执行的前提下,优先执行紧急型任务,以满足更多任务的截止期限,更充分地利用CPU资源;与原Linux的实时调度相比,SBRD能更有效地调度实时任务.
文摘In this paper, we describe a two-phase scheme to determine a scheduling of tasks with precedence con-straints that employ a reliability measure as one of the objectives in a Real-Time and heterogeneous distributed sys-tem. The simulation results show that, for task graphs with precedence constraints in a heterogeneous Real-Timesystem, the method performs significantly better than the two algorithms presented that do not consider reliabilitycost. Furthermore, the results suggest that higher computational heterogeneity is conducive to improving the schedu-lability of the reliability cost-driven (RCD)algorithm, while the opposite is true for the two non-RCD algorithms.
