Open Source Summit India 2026

Pressure Stall Information (PSI) is excellent for detecting CPU/memory/I/O contention via trigger windows and user-space polling, but it intentionally avoids attributing pressure to individual tasks. In practice, during severe pressure the “who did it?” question is hardest to answer: systems are sluggish, logs are noisy, and user-space observers can be delayed or miss the critical moment.
Building on PSI work presented at LPC 2024, this session introduces an optional, configurable, lightweight In-Kernel PSI Auto Monitor that captures thread-level contributors exactly when configured PSI thresholds are breached. The design avoids changes to PSI fast paths, requires no always-on daemon, and records contending tasks using existing kernel mechanisms and tracepoints.
I will share upstream patch status and experimental results from real embedded workloads, including PREEMPT_RT scenarios, quantifying trigger latency, overhead, and improvements in root-cause identification. Finally, I will demo a GenAI-assisted pipeline that parses monitor logs, generates timelines, and produces actionable summaries to speed up pressure-event debugging.