rick/LEDMatrix
1
0
Fork 0
mirror of https://github.com/ChuckBuilds/LEDMatrix.git synced 2026-10-10 09:06:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

fix(perf): count a stall even when the scroll state went missing across it

Browse Source 
On hdpi the stall watchdog logged a 1.9s stall during the hourly sports
refresh that the soak report never had: its worst gap was 655ms. The frame
that ended the stall was recorded as static, so its interval was dropped.

"Scrolling" is DisplayManager's scroll state at the moment a frame is
presented, and it goes missing mid-scroll: it expires after 2s without
activity, and any thread can clear it. Plugins call
set_scrolling_state(False) from their own display() (news, stocks, the odds
ticker's fallback), and Vegas captures some of those on the render thread
between two of its own frames. Vegas sets the state again only after its
next frame, so that frame is recorded as static -- along with the capture
or stall it followed.

One static frame between two scrolling frames, with the scroll resuming
within RESUME_SECONDS (1s), is now a frame of the scroll and both of its
intervals count, the first at the scroll's own hold (clearing the state
drops the hold to 1 too). Two static frames in a row still end the scroll.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
Chuck
2026-09-24 15:23:18 -04:00
co-authored by Claude Opus 5.5
parent b67818d5c5
commit 14c38a3189
3 changed files with 108 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/SCROLL_PERFORMANCE.md
+1 -1
View File
@@ -334,7 +334,7 @@ service's user.
| line | what it tells you |
|---|---|
| **Late frames** | Frames presented one or more refreshes after they were due: the panel showed the previous frame again, a visible hitch. **The pass/fail number**, 0.1% by default (`--max-late-pct`). Only intervals between two scrolling frames count, and a frame held for `frame_hold` refreshes is due `frame_hold` refreshes after the last. |
| **Freezes** | Gaps of 250 ms or more inside a scroll: recomposes, plugin handovers, blocking calls on the render thread. Reported but not failed on, because some are handovers between plugins rather than faults. |
| **Freezes** | Gaps of 250 ms or more inside a scroll: recomposes, plugin handovers, blocking calls on the render thread. Reported but not failed on, because some are handovers between plugins rather than faults. A gap still counts when the display's scroll state went missing across it (it expires after 2 s, and plugins clear it from their own `display()`), as long as the scroll carries on straight after. |
| **blit** | Copying the frame into the matrix canvas (`SetImage`). It grows with width × height × `pwm_bits`: ~5.5 ms at 512×64 with 8 bits on a Pi 4. It is the biggest fixed cost, and it sets the refresh rates a rig can hold one pixel per refresh at. |
| **wait** | Time blocked in `SwapOnVSync`, i.e. the slack left in each refresh. A p50 near zero means the rig has no headroom and anything extra lands a frame late. |
| **work** | Everything else between two frames: drawing, scrolling, and waiting for the GIL. A wide gap between its p50 and p99 is another thread getting in the way. |