Evolution of the Linux kernel

Existing research analyzing evolution of the Linux kernel considers the kernel together with loadable modules delivered with it or some specific subsystems of the kernel. The aim of this paper is to evaluate evolution of the kernel without loadable modules. It proposes a method for determining boundaries between them and evaluates evolution for all versions of the Linux kernel, released over the past 7.5 years. Also the paper presents a classification and a distribution of typical bugs that were fixed in the kernel, based on analysis of changes that have been made to stable branches of the kernel during the last 2 months of 2015. One can use the obtained results for evaluation of applicability of various methods and tools for software quality assurance.