[Show abstract][Hide abstract] ABSTRACT: In this paper we study the effect of processor affinity on real-time scheduling algorithms in uniform multiprocessor environments. For this reason we compare our two previously proposed algorithms called EFDF and FLLF, with two well know algorithms, namely global EDF and global LLF. Despite its non-optimality, EDF is an appropriate algorithm to use on multiprocessors. However, the performance of the traditional algorithms such as EDF and LLF significantly degrades in overloaded situations. Moreover, they produce a relatively large number of migrations which may prove unacceptable for use on some parallel machines. It is shown that our proposed algorithms not only demonstrate a performance as good as that of EDF in non-overloaded conditions but also overcome its deficiencies in overloaded situations in many aspects. Furthermore, they impose much less overhead on the system.
Application of Information and Communication Technologies, 2009. AICT 2009. International Conference on; 11/2009
[Show abstract][Hide abstract] ABSTRACT: In this paper a new laxity-based algorithm for scheduling real-time tasks on heterogeneous uniform multiprocessors is presented. In the proposed algorithm we have made use of laxity in two ways: Calculating the dynamic priority of tasks, and performing feasibility check. Besides, we have applied processor affinity to reduce the overhead in terms of task migration. The performance of this algorithm is then compared with that of EDF and LLF algorithms. It is shown that our proposed approach not only demonstrates a performance close to that of EDF in non-overloaded conditions but also has supremacy over EDF in overloaded situations in many aspects. Furthermore, it imposes much less overhead on the system.
Information and Communication Technologies: From Theory to Applications, 2008. ICTTA 2008. 3rd International Conference on; 05/2008