The Research On Linux Kernel Developers' Collaborative Model

With the development of computer and the Internet technology, a variety of computer software has provided a convenience for people's life. Especially, the OSS (open source software) with high efficiency and stability has attracted numerous users. OSS development is a new knowledge creation mode in which developers come from all over the world in a self-organization fashion to contribute to the software products. At present, researches on the knowledge creation mode of OSS development are mostly focused on summarizing the collective behavior patterns from a macroscopic view. The analysis of more thorough data of actual development activities may bring new opportunities for deepening our knowledge on the OSS development.In this thesis, based on static code data released from Linux Kernel and dynamic development data came from Git, we study the organization structure of contributors of Linux Kernel, code modification and audit modes, and developers' behavior characteristics by methods of complex networks and data analysis, and then we summarize the Linux Kernel developers' cooperative mode. The main contents are summarized as follows.(1) Through the analysis of Linux Kernel developers'collaborative coding network, it has obvious small-world and scale-free properties, and the network is in accordance with "core-periphery" structure, as shows that a small number of developers have done a lot development work, while the rest just occasionally participate. Furthermore, combined with network characteristics and data analysis, we find that Linux Kernel developers work with professional division and community division and then the hierarchy of organizational structure is formed.(2) Through the analysis of Linux Kernel developers' code modification network and submission network, we draw the vertically oriented development model in Linux Kernel. Under the leaders' maintenance, the Maintainer form cluster-type code modification structure. Meanwhile, the ordinary developers form a chain code modification structure around this cluster-type structure. In addition, based on the hierarchical organizational structure, Linux Kernel forms star structure of code review submission mode in the core of Maintainer, instead of the usual "peer review" model. Thus, this mode ensures high efficiency and standardization of code review.(3) On the basis of network characteristics and data analysis, this paper summarizes the collaborative model of Linux Kernel development. Leaders, Maintainers and developers form a centralized governance structure and vertical distributed collaborative model of bottom-up based on a chain of trust in accordance with their own division of labor. On the multi- parallel-branch code development structure, leaders are responsible for maintaining several major branches and the general direction of the Linux Kernel development. The Maintainer is the main code development and is responsible for community maintenance and code review submission. A large number of developers from all over the world contribute to the bug identified and modified by building their own Linux Kernel repository. This clear division of powers, role and community division ensure the high efficiency and sustainable development of Linux Kernel community.