Landslide is a Simics module designed for finding concurrency bugs in operating system kernels, with a focus on Pebbles. This paper explains the testing environment (the course, 15-410, and the kernel, Pebbles) and the testing technique; describes how Landslide takes advantage of certain features that Simics provides that other testing environments (such as virtualization) do not; outlines Landslide’s design, implementation, and user interface; presents some results from a preliminary evaluation of Landslide, and discusses potential directions for future work.