DDS Performance Evaluation for PREEMPT_RT Linux

In order to verify whether DDS meets real-time requirements, the network communication performance of the DDS middleware is evaluated based on the PREEMPT_RT Linux system and Loongson platform, including the communication latency, jitter, and the data throughput of the sending and receiving ends in the gigabit and 100M modes. Two sets of network cards are used for testing, one group uses Intel 82571 network card, and the other uses GMAC integrated network card. The test results show that the performance of DDS network communication is related to the network card used. In terms of the average value of throughput and latency, the performance of Intel 82571 is significantly better than GMAC. But in terms of the jitter value of the DDS communication, the original Intel 82571 driver is greater than 1 millisecond, far worse than the GMAC network card. After optimizing the driver of the Intel 82571 network card by turning off the interrupt adaptive speed control function, the test results show that although there is a slight loss in the throughput performance of the receiver, the communication latency jitter is less than 120 microseconds, which can meet the determinism in the millisecond-level embedded realtime system communication requirements.