Research on Linux Real-time and performance Evaluation for Loongson 3A3000 processor

Abstract

In order to solve the real-time problem of Linux system for loongson3A, the real-time enhancement design of Linux kernel is carried out by using the idea of PREEMPT_RT patch, the performance analysis support based on ftrace tool is improved, and the real-time optimization method based on reserved core scheduling is proposed. The real-time performance of the system is tested from four aspects: context switching, interrupt response, scheduling latency and network latency. Five context switching methods are proposed, including active switching, priority preemptive switching, semaphores, message queuing and signal distribution latency. A test method based on the internal timer of the PCI board is designed. The test results show that the maximum latency of real-time Linux system based on Loongson3A3000 is less than 30us, the reserved core scheduling latency is the minimum, and the maximum jitter of network communication latency is less than 120us. In conclusion, the system based on loongson3A3000 can meet the demand for hard real-time applications at millisecond level.