Modeling and Reconstruction of Response Times on Single Board Computers with RT-Linux

Abstract

Non-critical real-time systems can be developed by integrating three essential components: a Raspberry Pi single board computer, an operating system with a GNU/Linux distribution, and the PREEMPT RT real-time kernel extension; for its development, sizing, and correct operation, it is necessary to know the behavior of the response times of its tasks to meet the condition of predictability and compliance with deadlines. For this, it is necessary to define certain operating conditions such as the task to be studied, the priority, and complexity of the algorithm in execution, to know the dynamics of the task under study and determine its behavior. This paper presents a report on Ph.D. Thesis where two models were developed, the first one called ab initio and the second one based on the recursive mathematical expectation quotient, from which two estimation algorithms were generated. The response times under study were obtained from a task of the inversion of matrices with dimensions: 32×32, 64×64, and 128×128. The task under study is associated with the Round Robin scheduling policy with the highest priority.