A GcMonitor in src/common/frame_timing.py, installed once per process from gc.callbacks by the display manager (and render_bench), counts collections and seconds per generation, the longest, and those of 20 ms or more. A long one tags the next presented frame 'gc' in record(), so frame_soak shows its late rate under 'after work'; the stats file gains an additive 'gc' block printed as a 'Garbage collection' line; and a Render stall dump says when a long collection ran inside the stall. Diagnostic only: nothing tunes, freezes or disables the collector.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* perf(timing): say which render-thread work a late frame followed
The soak already says how often a moving frame reached the panel late, but
not what the render thread was doing just before it. Vegas does two kinds of
work there between frames -- building its strip (compose, extend) and, with
live elements, patching changed pixels into it -- and deciding whether either
is affordable needs their own numbers.
- FrameTimingRecorder.note_op(kind, nbytes) tags the next presented frame.
Totals gain op_frames, late_op_frames, op_freezes and op_bytes per kind;
aggregate() still takes frames without ops. The file schema is unchanged.
- Vegas tags compose and every strip extension (with the bytes it copied).
- frame_soak prints an "after work" table: frames, late %, freezes and MB
moved per kind, only when something tagged its work.
- render_bench gains --strip-screens (Vegas-sized strips), --patch-bytes /
--patch-every / --patch-where (in-place column writes, as a live element
update does) and --extend-every-screens / --extend-width (append + trim on
a fixed cadence that holds the strip's width).
No runtime behaviour changes: this is the measurement gate for live Vegas
elements.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* docs(changelog): note the frame-op attribution and bench modes
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
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>
