Mentorship Session: rtla timerlat: Debugging Real-Time Linux Scheduling Latency
Channel: The Linux Foundation
Date: 2024-04-03

Mentor: Daniel Bristot de Oliveira, Senior Principal Software Engineer, Red Hat
Debugging real-time Linux scheduling latency is a demanding task. And the demand for debugging this metric is increasing as more and more projects depend on it. For example, Linux in automotive and industrial applications is a trend. Historically, the preempt rt is tested using black box applications, but this approach has several limitations, as it does not help to find the root cause for bad latency values nor help to establish a pattern between different cases. rtla (real-time Linux analysis) is a kernel tool that facilitates debugging for real-time kernel features by integrating the measurements into kernel tracing features. In particular, rtla timerlat simplifies the debugging of scheduling latency by measuring the latency, tracing the main factors that cause a scheduling latency, producing a standardized auto analysis, and splitting the scheduling latency problem into small independent pieces of latency, all at once with user-friendly interface. This talk will present the rtla timerlat tool, the details of the timerlat tracer, and the tool's auto-analysis output, as well as demonstrate a strategy for debugging complex scheduling latency problems.