src/common/frame_timing.py times every frame the display presents, whoever drew it, and writes cumulative counters to /dev/shm. scripts/frame_soak.py grades a running service (late frames, freezes, where the time goes) and scripts/render_bench.py the hardware and render path alone. A stall watchdog logs the stacks behind any scroll held up for 250 ms or more (LEDMATRIX_STALL_WATCHDOG_MS lowers that). See docs/SCROLL_PERFORMANCE.md, "Soaking a rig".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>