Performance evaluation of real-time mechanisms on open embedded hardware platforms

Open hardware platforms are gaining wide popularity in various fields of technology for their accessibility and inexpensiveness. Although availability of these platforms is undeniable, the performance of these machines in handling tasks which require execution within critical time constraints is still in question. Moreover, technical documentation and support for open hardware are scarce in comparison to expensive commercially distributed platforms. In this paper, we present a detailed process to implement embedded Linux and the real-time extension of Xenomai to two popular open embedded hardware, BeagleBone Black and i. MX6Q SABRELite. Also, we analyze the response time of real-time mechanisms and its performance for inter-task communication (ITC) between real-time tasks. Response time of real-time mechanisms is an important measure to predict the realtime performance of each platform. The performance evaluation is performed both in kernel space and user space using the metrics of jitter, to estimate the periodicity of the cyclic task, and execution time of three real-time mechanisms including semaphore, message queue, and message pipe. The results of this study would serve as a guideline in developing real-time systems on low cost open embedded hardware platforms using the real-time Linux extension of Xenomai. Copyright; ICROS 2017.