A modified interactive oriented scheduler for GUI-based embedded systems

Most operating systems integrate a GUI environment to benefit for their users nowadays. The response time of such GUI environment is especially important for the handhelds in that they need more interactive services than general computer systems. A modified interactive oriented scheduler (MIOS) based on Linux kernel 2.6.21 is presented in this paper to provide a fast prototyping scheduling model for the GUI-based embedded systems. The main feature of MIOS is to decrease various unnecessary overhead in Linux kernel scheduler and provides a good balance between fast response and other requirements. We adopt the event-driven priority calculation mechanism to keep the system scalable and remove the array swapping model in Linux kernel to eliminate unstable latency. The dynamic priority allocation is based on time slice usage to provide efficiency and a starvation queue is proposed to provide an upper-bound starvation time and loose fairness. The simulation results show that the proposed scheduler not only provides quick response but also keeps the system in ideal throughput.