RT-Linux is a kind of embedded Linux, its real time performance is relative high among numerous kind of embedded Linux, but it requires the operation system have high real time performance and using priority inheritance protocol to solve the priority reverse problem in RT-Linux. In order to trace the system roundly, a kernel trace tool is designed, and used this tool to test the improvement. The test results show that the work eliminated the priority reverse problem, and advanced the real time performance of RT-Linux.