基于累计价值的最小松弛度优先算法  

Least-laxity-first Scheduling Algorithm Based on Accumulated Value

作　　者：范凯胤 王学奇[1] 谭小虎[1] 胡阳光[1] 石伟文 

机构地区：[1]空军工程大学航空航天工程学院,西安710038

出　　处：《火力与指挥控制》2017年第12期175-178,共4页Fire Control & Command Control

摘　　要：针对最小松弛度优先算法在任务裕度相同或相近的情况下,会出现不必要的上下文切换问题,采用任务的裕度和累计时间价值两个优先级的判定原则,这样对于正在执行任务裕度相同或相近,将要发生抢占时,使用累计价值作为评定标准,来达到减少任务间不必要切换,减少处理器开销的目的。经过对改进算法分析,满足可调度性原则,同时仿真结果表明,改进的LLF算法有效减少了任务间的切换,随着仿真时间的增加,对任务切换减少的效果越加明显。Pointing at the unnecessary switch of context in case task has same or similar margin in LLF algorithm,adopt the decision principle of task＇s margin and accumulated value.While the executing task is to be preempted,the standard of accumulated value is used to evaluation priority to decrease the number of switch in context,therefore,saveing resource of CPU.After analysing of improved algorithm,it meets schedulability.Simulation results show that the improved LLF algorithm can decrease the switch between task effectively,at the same time,along with time increase,the more obvious of reducing the number of switch in context.

关 键 词：最小松弛度优先算法 切换 裕度 累计价值 

分 类 号：TP312[自动化与计算机技术—计算机软件与理论]