Understanding Scheduling Behavior with SchedViz (Google Open Source Blog)

The Google Open Source Blog has an announcement of the release of the SchedViz tool that is used internally at the company "to discover many opportunities for better scheduling choices and to root-cause many latency issues". SchedViz provides a GUI to explore kernel traces: "The SchedViz UI displays collections in several ways. A zoomable and pannable heatmap shows system cores on the y-axis, and the trace duration on the x-axis. Each core in the system has a swim-lane, and each swim-lane shows CPU utilization (when that CPU is being kept busy) and wait-queue depth (how many threads are waiting to run on that CPU.) The UI also includes a thread list that displays which threads were active in the heatmap, along with how long they ran, waited to run, and blocked on some event, and how many times they woke up or migrated between cores. Individual threads can be selected to show their behavior over time, or expanded to see their details."