Research on Real-Time Embedded Software Scheduling Model Based on EDF

Abstract

Schedulability analysis is a very important part in real-time system research. Because the scenarios faced by real-time systems are very complicated, the functional characteristics must be combined with the predictability of response time. It is necessary to ensure the correctness of the calculation results and meet the real-time requirements. To solve this problem, we propose the IEDF (Improved Earliest Deadline First) algorithm, which is combined with the queuing theory model. The IEDF algorithm is based on the EDF (Earliest Deadline First) algorithm, which is more suitable for the scheduling of real-time embedded system. Scheduling of non-periodic tasks that arrive randomly. There are two types of tasks in the task set, tasks with a high static priority are executed first. In the ready queue of the same priority task, the deadline and execution time are considered. The comparison of simulation experiments shows that: the sum of waiting time in the execution of IEDF with enough deadline is much less than that of ordinary queuing algorithm; the number of errors in the execution of IEDF algorithm with deadline is much less than that of ordinary queuing algorithm. These results demonstrate the feasibility of the IEDF algorithm.

Keywords

• Deadline
• real-time scheduling
• EDF (earliest deadline first) algorithm