An Indirect Hotswapping System for Linux Kernel Modules

Most operating system kernels support functionality extension at runtime, but when it comes to upgrade or update the functionality of a component or module, it must be removed from the kernel before loading the new version of that component. To unload a component, all applications and other kernel components that are using it must be stopped to avoid inconsistency. This paper presents a hotswappable Linux kernel module system. Our system supports runtime module´s implementation replacement without affecting the normal functionality of the active dependent applications or modules. In our approach the kernel won´t be changed, only those modules that we want to hotswapp will be modified. The proposed system was developed on a Linux 2.6. We tested the hotswapping of some modules, we had previously prepared for that operation. The execution of the applications that were using the swappable modules was not affected. The latency introduced was not significant.