动态时间片缩放:一种优化Linux任务公平性的方法

Dynamic Time-Slice Scaling:A Scheme to Improve Fairness of Tasks in Linux

处理器动态电压频率调节技术,对Linux系统中并发任务的性能产生不同程度的变化,从而影响并发任务计算资源分配的公平性.提出了一种利用动态时间片缩放来优化任务公平性的方法,并基于Linux操作系统任务调度程序,加入动态时间片缩放模块,该模块通过读取CPU性能监控计数器,在线计算时间片缩放系数,并利用该系数对任务时间片长度进行动态缩放.实验表明,这种方法以较小的系统开销为价,极大地提高了Linux中并发任务计算资源分配的公平性.

The processor dynamic voltage and frequency scaling（DVFS）leads to unequal performance loss for concurrently running tasks in Linux, affecting the fairness of CPU sharing. This paper proposes a dynamic time-slice scaling scheme to improve the fairness of CPU sharing for concurrently running tasks. The method which is implemented based on Linux task scheduler dynamically scales the length of time-slice for each task using a time-slice scaling factor which is calculated based on the processor performance monitoring unit statistics. Experiment results show that dynamic time-slice sealing scheme can significantly improve the fairness of the CPU sharing with low overhead compared with the conventional Linux scheduler algorithm.