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Upstream PR 2994 LRU Active Visit
Upstream work · Actionable research · Research and retired work
Reviewed: November 1, 2026. Fork source:
b7140848(full SHAb71408480a3a979a9c584663e1d1f400904c8bb7). Latest stable checked: v0.8.136-0-g458730bf5373, September 30, source458730bf5373f1f0d027450fef7443e3af7a3ae1. GitHub state, branch recommendation, source presence and release availability are separate facts. See current status and release versus main.
| Current field | November 1, 2026 observation |
|---|---|
| GitHub source | Upstream #2994 |
| GitHub state / draft | Open / No |
| Current head | 781f5a5609330884e58208a60edd4cdc541afb93 |
| Originally reviewed head | 781f5a5609330884e58208a60edd4cdc541afb93 |
| Last metadata update (UTC) | 2026-10-18T20:59:12Z |
| Head versus original review | Same recorded head; metadata/state updates do not indicate a new proposal-code head. |
| Current action | Open proposal; refresh integration and focused tests before handoff. |
| Fork/release availability | This upstream proposal’s GitHub state does not establish full fork/release inclusion. The historical overlap below is scoped to its recorded fork baseline; use the current feature register for delivered fork behavior. |
The current head matches the recorded September review head. Later updated_at metadata does not establish changed proposal code. The original fork overlap remains a dated source comparison, not a fresh integration or native qualification result.
This refresh checked GitHub identity/state and the specific source boundaries named above. It did not rerun native games, XISO timings or integration qualification. Historical performance claims remain attached to their original heads.
The review below is preserved as written, including its original state, head, fork baseline and proposed handoff. Its present-tense statements apply to that dated review; the current disposition above governs today’s action.
| Field | Value |
|---|---|
| Upstream PR | xemu-project/xemu#2994 |
| State at 2026-09-21 audit | Open |
| Reviewed upstream head | 781f5a5609330884e58208a60edd4cdc541afb93 |
| Last upstream update seen | 2026-09-06 |
| Reviewed upstream base | f9b14039e5bb56ae2d8f028e31e7cc19f13f7e12 |
| Fork baseline | 82d04d84bdb3de956f20c3537e1da2cece0e8da2 |
| Relationship | Exact mechanism already present downstream |
| Related fork work | Mainkill1/xemu#47 |
| Contribution priority | High |
| Upstream contact status | No comment posted by this audit. |
The fork’s current lru_visit_active() already walks the global LRU list with safe iteration and calls visitors only for in-use nodes.
The upstream PR replaces hash-bin traversal with active-node traversal through the global list.
Current downstream behavior matches the proposed mechanism. This is an opportunity to offer validation and caller-audit results rather than another implementation.
Fork #47 concerns skipping free-node scans when a cache is full. It is a separate optimization. The current lru_try_get_one_free() observed in this audit still walks the global list unconditionally, so #47’s historical benchmark must not be used as evidence for #2994.
- A visitor may evict the current node without invalidating iteration.
- All in-use nodes are visited exactly once; free nodes are never visited.
- Callers do not rely on former hash-bin traversal order.
- Empty, full, collision-heavy, and mutation-during-visit cases retain LRU invariants.
Tell upstream the exact traversal is already exercised downstream and offer mutation/eviction coverage. Do not extrapolate hardware-specific benchmark percentages or #47 results.
- It does not prove the upstream branch merges cleanly with current upstream.
- It does not prove a native correctness or performance result unless a linked exact-head run says so.
- It does not transfer favorable performance percentages between hardware, renderers, games, or source heads.
- It does not authorize posting a comment or review upstream.
- Refresh the PR state, head SHA, description, changed files, and newest review comments.
- Recheck the corresponding fork implementation on current
main. - Run or cite the narrow regression on an exact source state.
- Verify every public link and remove private paths, captures, game data, credentials, and internal logs.
- Phrase source concerns as source concerns and reproductions as reproductions.
- State the uncovered behavior and evidence limit.
- Add the posted URL and upstream response to this page.
| Date | Upstream head | Action | Result |
|---|---|---|---|
| 2026-09-21 | 781f5a560933 |
Fork/upstream source comparison recorded | Handoff prepared; nothing posted |
DSP tooling guide and navigation updated November 2, 2026 for experimental PR #384, source 8f51d237. Capture/replay usage and limits.
The earlier wiki-wide review was published November 1, 2026. Emulator source: b7140848. Reviewed wiki content: 1d2b671. Current status · Release availability · Publication process.
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