This paper presents a Hierarchical Scheduling Framework (HSF) recorder for Linux-based operating systems. The HSF recorder is a loadable kernel module that is capable of recording tasks and servers without requiring any kernel modifications. Hence, it complies with the reliability and stability requirements in the area of embedded systems where proven versions of Linux are preferred. The recorder is built upon the loadable real-time scheduler framework RESCH (Real-time Scheduler). We evaluate our recorder by comparing the overhead of this solution against another (patched) recorder. Also, the tracing accuracy of the HSF recorder is tested by running a media-processing task together with periodic real-time Linux tasks in combination with servers. The tests are recorded with the HSF recorder, and the Ftrace recorder, in order to show the correctness of the experiments and the HSF recorder itself.
['Mikael Åsberg', 'Thomas Nolte', 'Shinpei Kato']
A Loadable Task Execution Recorder for Hierarchical Scheduling in Linux