Brussels / 4 & 5 February 2023


Graphing tools for scheduler tracing

Understanding scheduler behavior can be important for understanding application performance. In this talk, we present some tools that we have developed to help understand scheduling behavior on highly multicore machines. The tools to be presented enable 1) obtaining a graph showing what tasks are running on what cores, with a variety of coloring schemes, 2) detecting overload situations, and 3) stepping through a recorded execution. All tools rely on traces collected using trace-cmd. The tools make it possible to get an overview of the execution, as well as to study specific execution intervals. The source code is available at


Julia Lawall