Analysis of Linux Scheduling with VAMPIR

Analyzing the scheduling behavior of an operating system becomes more and more interesting because multichip mainboards and Multi-Core CPUs are available for a wide variety of computer systems. Those system can range from a few CPU cores to thousands of cores. Up to now there is no tool available to visualize the scheduling behavior of a system running Linux. The Linux Kernel has an unique implementation of threads, each thread is treated as a process. In order to be able to analyze scheduling events within the kernel we have developed a method to dump all information needed to analyze process switches between CPUs into files. These data will then be analyzed using the VAMPIR tool. Traditional VAMPIR displays will be reused to visualize scheduling events. This approach allows to follow processes as they switch between CPUs as well as gathering statistical data, for example the the number of process switches.