task: anchor L1 weight demand against the checkpoint in performance-ceiling-analysis #348

Current state: Existing Issue author @fake0fan has submitted PR #351, now 1694a0b, but this Issue still records Proposed, unassigned ownership and no accepted implementation delegation. The PR now contains the six content/coverage files plus 80 regenerated packaged knowledge files, and keeps Refs #348 rather than closure wording. At the prior 18c9a16 head, Ready had four software-check failures from stale packaged projections (including the reported 6 failed / 3538 passed full-check result). The 1694a0b5 incremental review clears the stale-index delta by static inspection; the subsequent current-head Ready result now has all six jobs passing, including both full-check and installed-package versions. This supersedes the earlier pending/full-check failure state, not the remaining review questions. The exact-head declaration now names claude-opus-5 and claude-opus-5-5 with effort unknown and extends its exception request to the generated records. The policy check still fails: explicit independent owner exception approval is absent, material AI author 1's model is unapproved, and author 2's effort is not allowed. The reviewer also retains the source/provenance-marker questions, blog-figure sourcing, and branch-only source-pin integration question; no merge strategy or new acceptance policy is chosen here. Source/index consistency and CI do not establish model/performance efficacy, acceptance or authority to close this Issue.
Decision needed: The requester/maintainers need to record the accepted scope/delegation and name the accountable and acceptance owners, which remain TBD below, including the existing gate-ownership/cross-link question. A submitted PR or reviewer's suggestions do not make those decisions.
Next action: Existing PR author @fake0fan retains the remaining source clarification and re-review work, accurate revision-specific documentation, and any exact-head policy-exception request to an authorized independent owner. The generated/packaged-consistency failure is no longer an outstanding repair at 1694a0b. Preserve the original proposed scope and acceptance text below; this status grants no implementation, policy-exception, merge or closure authority.

Goal and acceptance

methods/performance-ceiling-analysis L1 turns a model config plus a hardware
table entry into a runtime floor. It gates neither half of the demand side: the
skill has no procedure for checking that the weight and KV counts it divides by a
peak describe the model actually being deployed. safetensors appears nowhere
under this owner, while the mechanics already exist next door in
weight-loading-optimization
and a byte-level weight inventory already exists as an artifact pattern under
h3-c.

An L1 floor computed from a wrong parameter count is wrong in a way no roofline
check detects, because the roofline never looks at the model again. This issue
adds the missing prerequisite and records the external source it is derived from.

• Problem / desired outcome: a reviewed-source prerequisite that anchors L1's
  weight demand against the checkpoint before any number derived from it is
  reported, with its blind spot stated rather than implied.
• Completion criteria:
  • A reference document and a typed source-identity.json under
    methods/performance-ceiling-analysis/references/, recording the pinned
    commit, per-file git blob and sha256 digests, and the verbatim-vs-summary
    coverage of each inspected source.
  • A prerequisite step in SKILL.md covering two gates: the bidirectional
    per-tensor checkpoint join, and the per-rank weight ledger. The first needs no
    parallelism layout; passing it certifies nothing about per-rank bytes.
  • An explicit statement of what the weight anchor does not anchor (KV
    semantics: a windowed and a global attention with the same head dims have
    byte-identical weights).
  • A metadata.json source entry and a docs/reference-matrix.md row.
  • locally_verified stays false; empirical_validation stays not_run.

Scope and constraints

• In scope: documentation and skill-library content under the existing
  performance-ceiling-analysis owner, plus the two matrices' source rows.
• Out of scope:
  • The bound model proposed in [RFC] Per-task SOL modeling and a KDA-flow gap metric for fused operators #303. This issue adds a prerequisite check, not a
    bound, and does not depend on [RFC] Per-task SOL modeling and a KDA-flow gap metric for fused operators #303 being accepted.
  • The Class A / Class B vocabulary of [RFC] Per-task SOL modeling and a KDA-flow gap metric for fused operators #303. Note for reviewers: the cited
    source uses Class A–Class E for an unrelated taxonomy (verification rule
    kinds), so neither vocabulary should be imported alongside the other.
  • Importing or vendoring any measured kernel corpus. External measurement data
    stays a reference with stated availability, per the
    knowledge-base contract.
  • Any new skill ID, registry entry or skill-index.json change.
  • Any measurement, benchmark or performance claim.
• Relevant dependencies, shared interfaces or limits: weight-loading-optimization
  keeps ownership of loading mechanics; this issue adds only the correctness gate
  and cross-links it.

Ownership and authorization

• Proposed by / actual requester: repository owner
• Status: Proposed
• Accountable parent (Issue-level owner, if assigned): TBD
• Slice implementer(s) / acting contributor (if assigned): TBD
• Goal-acceptance owner: TBD
• Accepted decision or scoped delegation: Not yet granted

Inputs and deliverables

• Relevant sources, revisions or linked issues:
  • github.com/shenh10/HuggingArch @ facbbbc96856e558b9084a94a5070b2e2c86cf0b
    (MIT; single init repo commit dated 2026-11-04T02:24:14Z), inspected
    2026-11-04. Readset: docs/validation.md, docs/measured_calibration.md,
    docs/evaluation_model.md, docs/known_limitations.md,
    backend/arch/validate/_matching.py, backend/arch/validate/_weight_ledger.py,
    backend/arch/validate/_ablation.py, backend/measure/scope.py,
    kernel_bench/emit.py.
  • A companion blog post dated 2026-10-08, read in part. The repository
    post-dates it by roughly four weeks and carries no history, so the post's
    figures are not attributable to this commit and are recorded as unverified
    where they are recorded at all.
  • Related: [RFC] Per-task SOL modeling and a KDA-flow gap metric for fused operators #303 (proposed; not a dependency of this issue).
• Expected artifacts: one PR touching only the files named under completion
  criteria.

Completion and closure

• Who accepts completion and may close: the named acceptance owner, not the PR merge.
• Remaining uncertainty / next decision: whether the two gates belong to this
  owner alone or should be cross-declared as a reference from
  weight-loading-optimization; the PR proposes the former with a cross-link.