Evolution and stability of Linux kernels based on complex networks

This paper presents a novel method to study Linux kernel evolution using complex networks. Having investigated the node degree distribution and average path length of the call graphs corresponding to the kernel modules of 223 different versions (V1. 1. 0 to V2. 4. 35), we found that the call graphs are scale-free and smallworld networks. Based on the relationship between average path length and nodes, we propose a method to find unusual points during Linux kernel evolution using the slope of the average path length. Using the unusual points we identify major structural changes in kernel modules. A stability coefficient is also proposed to describe quantitatively the stability of kernel modules during evolution. Finally, we verify our result through Vasa's metrics method.