The Limitations of Fixed-Priority Interrupt Handling in PREEMPT RT and Alternative Approaches
نویسندگان
چکیده
Threaded interrupt handling is a common technique used in real-time operating systems since it increases system responsiveness and reduces priority inversions. The PREEMPT RT Linux kernel patch introduces aggressive threaded interrupt handling into the Linux kernel. However, under PREEMPT RT, interrupt handling threads must be assigned a single fixed scheduling priority. This can become a significant limitation when an interrupt-generating device is shared by threads of differing priorities. In this paper, we show that there is no good option for assigning a single fixed priority to an interrupt handling thread in such cases. We then survey alternative approaches from academic literature and commercial real-time operating systems to inspire new solutions in PREEMPT RT.
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