VEC中基于动态优先级的抢占式任务调度方法  

Preemptive task scheduling scheme based on dynamic priority in VEC

作　　者：贾梦欣 范艳芳[1] 宋志文 陈若愚[1] 蔡英[1] JIA Mengxin;FAN Yanfang;SONG Zhiwen;CHEN Ruoyu;CAI Ying(Computer School,Beijing Information Science&Technology University,Beijing 100101,China)

机构地区：[1]北京信息科技大学计算机学院,北京100101

出　　处：《北京信息科技大学学报（自然科学版）》2023年第6期11-20,共10页Journal of Beijing Information Science and Technology University

基　　金：北京信息科技大学促进高校内涵发展-面向边缘计算的创新科研平台建设项目(2020KYNH105);北京信息科技大学“勤信人才”培育计划(QXTCP C202111)。

摘　　要：在车载边缘计算(vehicular edge computing,VEC)环境中,车载应用的计算任务常被卸载至VEC服务器上处理,在解决车辆计算能力不足的同时降低车联网通信服务的时延。然而,服务器有限的计算资源以及不合理的调度顺序会导致任务的失败率升高,甚至危及车辆用户安全。针对此问题,首先分析车载应用的特点,设计一个多因素任务优先级模型。其次,设计基于任务紧迫性的优先级动态调整策略。最后,设计结合任务最大可等待时间和优先级的任务抢占机制,使紧迫性升高的任务及时得到处理,从而降低任务失败率。仿真结果表明,相比于直接抢占调度方案,所提方案可以减少任务争抢资源所带来的抢占次数,降低频繁抢占对失败率的影响;相比于静态优先级调度和高响应比优先调度方案,所提方案可以实现在任务时延约束下失败率最小化的目标。In vehicle edge computing(VEC)environment,the computational tasks of in-vehicle applications are often offloaded to VEC servers for processing,which reduces the latency of telematics communication services while addressing the lack of vehicular computational power.However,the limited computational resources of the server and unreasonable scheduling order can lead to higher failure rate of tasks and even endanger the safety of vehicle users.To address this problem,the characteristics of in-vehicle applications were analyzed and a multi-factor task prioritization model was designed firstly.Secondly,a priority dynamic adjustment strategy based on task urgency was designed.Finally,a task preemption mechanism that combined the maximum wait time and priority of tasks was designed,so that tasks with increased urgency can be processed in time,thus reducing the task failure rate.Simulation results show that compared with the direct preemption scheduling scheme,the proposed scheme can reduce the number of preemptions caused by tasks competing for resources and reduce the impact of frequent preemptions on the failure rate.Compared with the static priority scheduling and high response ratio priority scheduling schemes,the proposed scheme can achieve the goal of minimizing the failure rate under the task delay constraint.

关 键 词：车载边缘计算 动态优先级 抢占式调度 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]