Embedded Linux in Real-Time Applications: Performance Enhancements of Experimental Fully-Preemptible Capabilities over the Standard Kernel in a Critical Mobile System

This paper presents the results of a performance evaluation of a standard Linux-based control system employed in many critical embedded applications, and identify improvements in responsiveness and efficiency obtainable by specific modifications aimed at enhancing the preemptive and real-time capabilities over the standard OS kernel. The study was accomplished with the aid of a tool for runtime performance measurement developed in the scope of the INCT-SEC GT4 activities, which collects information of the interaction between the application, operating system and hardware during the process execution. Experiments carried out with the embedded control software of another running project of INCT-SEC, a tactical indoors robot, reveal potential significant improvements in efficiency and responsiveness which can be exploited by merely replacing the kernel, without any modification on the application itself. It is also offered an insight on how the characteristic of the application in terms of CPU and I/O usage patterns can influence the system performance, and how such knowledge can be used in the project of embedded application such as to optimize the dependability and efficiency of critical applications.