ITERATE-2.V: scheduler priority aging closes 18-day AUDIT-049 wedge

Priority aging in xenia-cpu/scheduler.rs:pick_runnable
(effective_priority = base + age_bonus(now_round - last_run_round),
capped at +31, AGING_ROUNDS_PER_BONUS=1). Strict-priority was parking
priority=0 threads behind CPU-bound priority=15 audio mixer
(sub_824D1328 guest spinwait at PC=0x824d1404 on CPU5). Aging
eventually picks the starved thread, breaking the producer-consumer
cycle that caused 5-tid wedge at PC=0x824ac578 since AUDIT-049 (10 May).

Cascade observed: tid=13 clean exit; events 121K -> 13M (107x); last
host_ns 767ms -> 51,011ms (66x); 8 new threads spawn; VdSwap 1 -> 2.

Complete two-day iterate sequence (2026-05-27 -> 2026-05-28):
- 2.F: VdSwap drain timeout 900ms -> 1ms (xenia-gpu/handle.rs); 876x
       perf win on VdSwap kernel callback
- 2.H: vA0000000 physical heap bucket added (state.rs, exports.rs);
       ctx_ptrs now in 0xA0000000-0xBFFFFFFF range matching canary
- 2.L: Phase-A diff harness categorized [return_value mismatch],
       [status mismatch], [args_resolved.path mismatch] tags
       (tools/diff-events/diff_events.py); closes reading-error #41
       (silent test-harness state leak invalidating trace diffs)
- 2.M: always-on exit-thread-state.json sibling to Phase-A JSONL
       (event_log.rs + xenia-app/main.rs); closes reading-error #42
       (Phase-A blind to blocked-forever waits)
- 2.Q: signal.match kernel instrumentation in NtSetEvent /
       NtReleaseSemaphore / KeSetEvent / KeReleaseSemaphore
       (exports.rs); emits target_handle + waiter_count + waiter_tids
- 2.T: wake.requested kernel instrumentation in wake_eligible_waiters
       (exports.rs); emits target_tid + transition + new_state
- 2.V: scheduler priority aging (xenia-cpu/scheduler.rs) [keystone]

Plus accumulated WIP from earlier May (contention_manifest,
phase_b_snapshot, xam/xaudio enhancements, analysis db, xex loader,
xenia-app main loop, etc.). Audit-runs/ artifacts remain untracked
per project convention.

Tests: 300 xenia-cpu / 227 xenia-kernel / 5 xenia-app / 19 xenia-path
/ 30+ smaller suites -- all PASS, 0 regressions. Determinism preserved
(2x cold runs bit-identical at 13,003,881 events post-2.V).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
MechaCat02
2026-05-29 07:27:26 +02:00
parent e6d43a23ac
commit ad45873a1b
50 changed files with 14389 additions and 506 deletions

View File

@@ -0,0 +1,55 @@
---
address: 0x8245EC10
classification: dispatch_table_method
confidence: high
last_audit: 060
aliases:
- "canary γ-wedge signaler B"
- "dispatch_table 0x820B5830 slot 1"
---
# sub_8245EC10 — dispatch_table slot 1 method, canary γ-wedge signaler B
## Synopsis
Method living at slot 1 of `dispatch_table @ 0x820B5830`. The dispatch table is installed at struct offset 0 (vptr) by [sub_8245FEB8](sub_8245FEB8.md). In canary, this method is one of two NtSetEvent caller-LRs that signal the AUDIT-059 file-IO completion wedge dup handle (LR `0x8245ED80` post-`bl 0x824AA2F0`). In ours it fires 2× total but not on the wedge handle.
## Evidence
- Located at slot 1 of dispatch table `0x820B5830`. Slot 0 is `sub_8245F1D0`.
- The dispatch table is referenced from:
- `sub_8245F1D0+0x1C` (self-recursive)
- `sub_8245FEB8+0x100` (= `0x8245FFC0`, the `stw r11, 0(r31)` vtable install)
- AUDIT-060 Probe O ours: fires **2× in ours** (`--ctor-probe`); both fires come from `sub_8245FEB8` callers (transitively, via the installed dispatch-table dispatch).
- AUDIT-059 Probe C canary: at LR `0x8245ED80` (`= sub_8245EC10+0x170` or similar internal PC after `bl 0x824AA2F0`), this fn is one of two distinct canary NtSetEvent caller-fns that signal the wedge dup handle (per cross-run `r31` invariant; the other is [sub_82458B90](sub_82458B90.md)).
- Both canary signalers wrap `bl 0x824AA2F0` (NtSetEvent wrapper). Each fires once per file-IO completion in canary.
## Activation
Indirect dispatch. Reachable only via `bctrl` against an object whose vptr was set to `dispatch_table @ 0x820B5830`. The install happens via [sub_8245FEB8](sub_8245FEB8.md). No direct `bl` callers — and that is correct for a `dispatch_table_method`.
## Static graph
- Static callers (direct `bl`): **0** (correct — indirect dispatch only).
- Callees: includes `bl 0x824AA2F0` (NtSetEvent wrapper) at internal PC near `+0x170` (canary LR `0x8245ED80`).
## Audit log
- **AUDIT-060 (2026-05-12)** — fires 2× in ours; not dead. AUDIT-059's "dead via 0 static callers" framing was too narrow — dispatch_table reachability needs runtime-installed-vptr awareness, not just static `bl` xref BFS. [confirmed alive]
- **AUDIT-059 (2026-05-11)** — identified as canary NtSetEvent signaler B for the file-IO completion wedge dup handle. Cross-run `(tid, r31)` invariant matched. [confirmed for canary signaler role]
- **AUDIT-059 (2026-05-11)** — claimed dead in ours due to 0 static callers + dispatch-table installer ([sub_8245FEB8](sub_8245FEB8.md)) ALSO claimed dead. [STATUS: falsified by AUDIT-060]
## Open questions
- What handle does `sub_8245EC10` signal in ours? (Two fires — capture r3 at each fire to identify the target handles.)
- Why doesn't it signal the wedge handle in ours? Either (a) it's running on the wrong object (different installed instance), or (b) the work item it's processing has a different completion-event field.
- Cross-engine method match: is canary fire #1 and ours fire #1 the same logical event? Compare object base (would need new instrumentation).
## Cross-references
- Installed at: `dispatch_table @ 0x820B5830` slot 1.
- Vptr installer: [sub_8245FEB8](sub_8245FEB8.md).
- Sibling method (slot 0): `sub_8245F1D0` (not yet dossierd).
- Sibling canary signaler: [sub_82458B90](sub_82458B90.md).
- Audits: 059, 060.
- Artifacts: `audit-runs/audit-059-gamma-wedge/canary-setwrapper.log`, `audit-runs/audit-060-fnptr-array-bootstrap/`.