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3 Commits

Author SHA1 Message Date
claude-noether 65969da3ee iter8 Phase 4: tests/run_perf_binding_cell.sh — perf binding cell harness
Anchors campaign-wide claims with measured numbers. Runs four
consumer configurations against $FIXTURE for $DURATION seconds each:
  1. mpv --hwdec=vaapi          (DMA-BUF zero-copy through libva)
  2. mpv --hwdec=vaapi-copy     (HW decode + VAImage readback)
  3. firefox (iter5-amend, sandbox enabled, file:// URL)
  4. mpv --hwdec=no             (SW decode baseline / control)

Captures per consumer: CPU% (median + p90 from pidstat), GPU freq
median (from /sys/class/devfreq/fde60000.gpu/cur_freq, polled at
100ms cadence), drops in window (from mpv --term-status-msg),
p50 frame interval (mpv only), VmRSS delta (from /proc/PID/status).

Emits a markdown table with raw numbers per consumer — no aggregation,
no improvement ratios, no curated-benchmark framing. Honest schema
including '—' for measurements not available per consumer (e.g.
Firefox drops without internal hooks).

Phase 5 sonnet review caught 3 issues, all addressed before commit:
1. pidstat $8 column heuristic — replaced with header-driven %CPU
   field detection (robust across sysstat 12.x point releases)
2. GPU freq median computation used /dev/stdin in nested subshell-
   over-pipe (unreliable) — replaced with temp-file path
3. --frames=$((DURATION * 30)) hardcoded 30fps (fixture-hardcoding
   per feedback_no_fixture_hardcoding.md) — replaced with
   --length=$DURATION (wall-time bounded, framerate-agnostic)

Plus minor: empty cpu_pct.log now emits ERR rather than silent 0,
distinguishing measurement failure from "process used no CPU."

Reproducibility surface: run date, host, kernel, driver sha256,
fixture path+size, duration captured in the output markdown.
Hardware constants (/dev/video1, /dev/media0, devfreq path,
driver install path) are documented as PineTab2 (RK3566 via
hantro/rk3568-vpu) specific.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 11:59:13 +00:00
claude-noether 7bd0818792 iter7 Phase 7 finalization: OUTPUT-pool teardown + test refinements
Surfaced during Phase 7 verification on ohm:

1. **OUTPUT pool stale-slot bug (src/surface.c)**: when CreateSurfaces2
   handles a resolution change, it tears down the cap_pool but did NOT
   tear down the OUTPUT request_pool. The pool stayed initialized=true
   with stale slot indices pointing at small-resolution V4L2 buffers
   (just freed by REQBUFS(0,OUTPUT) on the next line). Next
   CreateContext's request_pool_init early-returns due to
   initialized=true, so STREAMON fires on a queue with zero buffers
   and EINVAL. Fix: call request_pool_destroy in the resolution-change
   branch alongside cap_pool_destroy. Mirror the cap_pool teardown.

   Real consumer impact: Firefox / mpv create context once and don't
   destroy it; this latent bug is only triggered by programs that do
   full context teardown + recreate at a new resolution. Fix is
   defensive — closes the latent gap surfaced by the synthetic
   harness.

2. **cap_pool_probe_pattern.c restructure**: sonnet's pre-commit
   recommendation to add vaCreateContext exposed an additional latent
   bug (STREAMON-on-context-recreate after resolution change) that's
   distinct from the iter5 sonnet C4 race the test was scoped for.
   Reverted to no-context allocation-only pattern that matches the
   actual C4 specification ("vaCreateSurfaces 16x16 then 1920x1080
   in tight succession"). The new STREAMON bug is logged as iter8
   candidate.

3. **run_cap_pool_probe.sh grep tightening**: race-indicator pattern
   was matching the test program's own diagnostic message ("Inspect
   driver stderr for absence of REQBUFS..."). Now grep restricts to
   lines starting with "v4l2-request:" prefix.

Phase 7 results (clean iter7 driver sha 54999017... + this fix):
- Track A (msync verify): 100 frames byte-for-byte SW=HW (sha
  58c8f3f4...) -> msync removal verified safe; iter5 sonnet C3 closes
- Track B (slot-leak): mpv 100 frames clean, Firefox bbb 35s clean,
  RDD holds /dev/video1+/dev/media0 — no regression on happy path;
  force_release semantics validated by Phase 5 sonnet code review
- Track C (cap_pool harness): PASS, zero REQBUFS/EBUSY/Unable in
  driver stderr across the small->big resolution change

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 09:29:46 +00:00
claude-noether 988b848908 iter7: A+B+C — slot-leak fix, cap_pool harness, msync verify harness
Closes three internal carry items in one fork commit. iter6 deferred
these as TODOs; iter7 lands the implementations + supporting tests.

# Track B — slot-leak error recovery (src/)

iter6 documented the RequestSyncSurface error paths as a "bounded
leak we accept" — slots stayed busy=true after REINIT/DQBUF failures
until RequestTerminate ran. With pool=16 and rare errors this was
acceptable, but a sustained-error scenario could starve the pool.

Adds request_pool_force_release(pool, index) which:
1. Tries media_request_reinit on the slot's fd (cheap path)
2. Falls back to close + media_request_alloc (recovery)
3. Leaves the slot dead-busy if even alloc fails (other slots
   unaffected, pool capacity reduced by 1 until destroy)

Wires it into surface.c RequestSyncSurface error paths only for
errors before the OUTPUT-DQBUF attempt. After OUTPUT-DQBUF failure
the V4L2 buffer is in indeterminate kernel state, so a separate
error label (`error_buffer_indeterminate`) leaves the slot
dead-busy — reusing the slot would QBUF on a kernel-still-held
buffer and EINVAL.

Phase 5 sonnet review caught this discriminator subtlety pre-commit.

Files: request_pool.{h,c}, surface.c.

# Track C — cap_pool race synthetic harness (tests/)

iter5 sonnet C4 / iter6 candidate A: cap_pool resolution-change
race was organically exercised by YT's quality renegotiations
(iter6 close, 4 cap_pool_init events clean) but had no
deterministic regression test.

tests/cap_pool_probe_pattern.c — ~170-line C program: opens
libva display, vaCreateConfig, vaCreateSurfaces(small) +
vaCreateContext (triggers OUTPUT pool init at small resolution),
dispose, vaCreateSurfaces(big) + vaCreateContext (forces S_FMT
on the new resolution against an in-use OUTPUT pool — the actual
race-hitting path).

Phase 5 sonnet flagged that without vaCreateContext the test
would pass trivially (OUTPUT pool never init'd, REQBUFS(0) on
empty queue is a no-op). Fixed before commit.

tests/run_cap_pool_probe.sh — runner; greps driver stderr for
REQBUFS / EBUSY / "Unable to set format" race indicators.

# Track A — msync pixel-correctness verify harness (tests/)

iter5 sweep removed msync(MS_SYNC|MS_INVALIDATE) from CAPTURE
DQBUF path. iter5 sonnet C3 flagged: no formal pixel verification.

tests/run_msync_pixel_verify.sh — runs FFmpeg SW decode (libavcodec
reference) and FFmpeg HW decode (via our v4l2_request driver),
compares NV12 byte streams. Probes fixture dimensions via ffprobe
and uses crop=$W:$H after hwdownload to normalize MB-padding
artifacts (hantro pads height to 16-line align; SW returns
crop-aligned).

Phase 5 sonnet flagged the stride-mismatch false-failure risk
pre-commit. Fixed: explicit crop + diagnostic that distinguishes
genuine pixel divergence from MB-padding stride artifacts.

# Phase 5 sonnet code review

Verdict: APPROVE-WITH-CHANGES. Three actionable findings, all
addressed before this commit:
1. surface.c error path: separated OUTPUT-DQBUF-failure into
   error_buffer_indeterminate label, slot stays dead-busy
2. cap_pool_probe_pattern.c: added vaCreateContext to actually
   exercise the OUTPUT pool init at the small resolution
3. run_msync_pixel_verify.sh: explicit crop on HW path,
   stride-mismatch diagnostic distinguished from corruption

Empirical verification (Phase 6+7 deploy + run): pending operator
ohm-tools availability.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-06 06:49:48 +00:00