摘要
节能设计是嵌入式实时系统中一个重要的研究方向.目前的研究大多采用串行任务模型,很少关注并行任务.文中研究了在离散工作模式与实时约束下,多核平台下的线性加速比并行实时任务的能耗最小化问题.文中假设所有处理器核都支持DVS技术且加速比是线性的,在此条件下,文中首先给出一个定理证明了当各任务执行在系统全部核上时系统能耗最小.然后,将问题建模为一个0-1整数线性规划,利用最早截止期优先算法确定任务调度,并给出了两个高效的节能算法确定各任务的工作频率.文中最后通过大量的模拟实验,证明提出的算法的效果显著,可以达到几乎与最优解相同的节能效果.
Energy-efficiency is one of the most important design goals for embedded real-time systems. While much work has addressed the problem for sequential tasks where each task can run on only one processor at a time, little work has been done for parallel tasks where an individ- ual task can be executed by multiple processors simultaneously. In this paper, we study the energy minimization problem for parallel task systems with discrete operation modes and under timing constraints. We focus on a system with DVS （Dynamic Voltage Scaling） enabled proces sors and workload satisfying linear speedup ratio model. We first prove a lemma, a sufficient con dition for minimizing the system energy, which indicates that the overall system energy is mini- mized when each task runs on all of the processors simultaneously. Then, adopting the earliest deadline first （EDF） scheduling policy and the lemma proved, we employ a 0-1 Integer Linear Program （0 1 ILP） to derive the optimized frequency assignment with minimized energy consump- tion. Furthermore, two polynomial time complexity heuristics with opposite frequency assign- ment searching directions are also proposed. The simulation experiment results show that the proposed heuristics can significantly reduce the system energy consumption and consume nearly the same energy as does 0-1 ILPs.
出处
《计算机学报》
EI
CSCD
北大核心
2013年第2期384-392,共9页
Chinese Journal of Computers
基金
国家自然科学基金(60973017)
博士学科点专项科研基金(20110042110021)资助~~
关键词
实时系统
并行任务
能耗最小化
动态电压缩放
多核
real-time systems
parallel tasks
energy minimization
dynamic voltage scaling
multi-cores
