A Light Lock Management Mechanism for Optimizing Real-Time and Non-Real-Time Performance in Embedded Linux

In a real-time Linux system, the critical sections are known as the main factor delaying the execution of real-time tasks. Traditional approaches to overcoming this issue have given less consideration to both real-time and non-real-time tasks. In this paper, we propose a new lock management mechanism to improve the real-time performance with a small penalty for non-real-time tasks. Using this mechanism, we guarantee the deadlines of real-time tasks while keeping the penalties accruing for non-real-time tasks small. We implemented a prototype system in Linux 2.6.20. Experimental results showed that the worst-case OS latency of real-time task is reduced to 19% of the original one, while the penalty for a non-real-time task is 10.1% of the original. The results also showed that the lock management mechanism proposed in this paper is efficient and useful for a future real-time Linux system.