Upstream PR 2996 Device Sized Buffers

Upstream PR #2996 — Size Vulkan storage buffers from device limits

Upstream work · Actionable research · Research and retired work

Current disposition — November 1, 2026

Reviewed: November 1, 2026. Fork source: b7140848 (full SHA b71408480a3a979a9c584663e1d1f400904c8bb7). Latest stable checked: v0.8.136-0-g458730bf5373, September 30, source 458730bf5373f1f0d027450fef7443e3af7a3ae1. 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 #2996
GitHub state / draft	Open / No
Current head	4ab056ef5bfaa707731d1b3e0ee062855d52c937
Originally reviewed head	4ab056ef5bfaa707731d1b3e0ee062855d52c937
Last metadata update (UTC)	2026-10-18T20:59:11Z
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.

Historical review — September 21, 2026

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.

← Upstream Work

Field	Value
Upstream PR	xemu-project/xemu#2996
State at 2026-09-21 audit	Open
Reviewed upstream head	4ab056ef5bfaa707731d1b3e0ee062855d52c937
Last upstream update seen	2026-09-06
Reviewed upstream base	f9b14039e5bb56ae2d8f028e31e7cc19f13f7e12
Fork baseline	82d04d84bdb3de956f20c3537e1da2cece0e8da2
Relationship	Complementary allocation work
Related fork work	Related transient-buffer growth/failure-handling work
Contribution priority	Medium
Upstream contact status	No comment posted by this audit.

Summary

Upstream sizes storage buffers using selected-device limits instead of fixed constants.

Upstream scope

Runtime sizes must respect physical-device limits and every consumer must use the actual successful size.

Corresponding fork work

The fork has separate work around growing transient buffers and propagating preparation failures. That does not replace device-sized initial allocation.

Difference that must remain explicit

A requested size, configured maximum, and successful allocation size can differ. Paired staging/device buffers, descriptors, reservations, and bounds must use one authoritative result.

Transferable regression and review cases

• Simulate device limits below and above the old fixed value.
• Verify paired buffers and descriptor ranges use the same successful size.
• Boundary reservations reject without overflow.
• Snapshot/reset/recreation paths rebuild size-dependent state.

Suggested upstream handoff

Offer failure-propagation and bounds lessons, while treating the device-sized policy as upstream-specific.

Claims this page does not support

• 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.

Before sending anything 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.

Tracking log

Date	Upstream head	Action	Result
2026-09-21	4ab056ef5bfa	Fork/upstream source comparison recorded	Handoff prepared; nothing posted

References

• Upstream PR #2996
• Fork repository
• Upstream Work
• Pull Request Lessons