Design and Implementation of High-Precision Timer in Linux

Clock precision directly affects that if tasks can be timely responded and scheduled or not. As a time-sharing system, Linux cyclical time granularity can not achieve microsecond response precision. Simply raising clock frequency means that the clock interrupt´s process will take up too much time of processor. And it makes the system´s effective utilization decline. This paper introduces some ways of improving clock´s precision for real-time Linux, analyses the theory of MontaVista Linux high resolution timer (HRT) mechanism, implements a high-precision clock in current popular embedded operating systems through modifying Linux kernel to design a Linux high-precision timer to raising the Linux clock precision effectively.