[nalinaly]

A5 L3 captures can omit memory primitives even when capture counters report zero drops and exclusive-time accounting balances. Bootstrap and the dispatch loop clear the Scalar observer after the resident entry has bound it.

Preserve the resident-owned binding across both phases. Keep initialization and teardown cleanup at the resident boundary. Add regressions that execute real bootstrap and dispatch paths and require atomic, bypass-load, cache-publication and barrier records.

Validation:

• Both new regressions fail before the fix because the observer is cleared and primitive counts are zero.
• All 132 startup/executor cases pass with the fix; all four affected C++ test targets pass.
• Applicable pre-commit checks and git diff --check pass.
• A5 onboard: three consecutive L3 captures passed numerical validation with 96 complete worker streams, zero drops, conserved exclusive time, and nonzero atomic, ld_dev, DCCI and DSB counts. The default -O3 AICore build includes all eight resident objects.

Related to #2991.

[coderabbitai]

No actionable comments were generated in the recent review.

Walkthrough

Bootstrap and dispatch no longer clear the scalar observer binding on entry. run_resident_scheduler still clears it at resident-run entry. New tests check scalar trace records and verify that the binding clears when its scope ends.

Changes: Resident Scalar Observer Lifetime

Layer / File(s)	Summary
Preserve binding across resident execution src/a5/runtime/host_build_graph/aicore/resident_scheduler_impl.h, tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_gm_mix_startup.cpp	Bootstrap and dispatch no longer clear the scalar observer binding on entry. Tests check phase records during bootstrap and dispatch, and verify that the binding clears at scope end.

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Possibly related issues

• hw-native-sys/simpler#2667 — Tracks A5 AICore scheduling delivery, which includes the resident scheduling paths changed here.
• hw-native-sys/simpler#2666 — Covers A5 capture and DFX integration; this PR adds tests for scalar trace records during resident execution.
• hw-native-sys/simpler#2631 — Covers scheduler lifecycle and HBG readiness, which overlaps the bootstrap and dispatch paths changed here.

Possibly related PRs

• hw-native-sys/simpler#2989 — Introduced the resident scheduler functions that this PR updates to preserve the scalar observer binding.

Merge Risk: Minimal · up to 0ffdf

This change keeps scalar observer tracing active through bootstrap and dispatch, so A5 captures include memory primitives. No actionable merge risk was found. Onboard verification is reportedly still in progress.

Pre-merge checks: 4

Check name	Status	Explanation
Title check		The title clearly identifies the main change: preserving A5 Scalar observers throughout resident execution.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Description check		The pull request description directly matches the changes. It explains preserving the Scalar observer binding across bootstrap and dispatch, retaining cleanup at the resident boundary, and adding regr…

Full details: Description check

Explanation

The pull request description directly matches the changes. It explains preserving the Scalar observer binding across bootstrap and dispatch, retaining cleanup at the resident boundary, and adding regression tests for the affected trace records.

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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_{A rabbit checks the traces at dawn,
While bootstrap keeps the binding on.
Dispatch leaves its records clear,
Then scope-end cleanup draws near.
I twitch my nose: the phases show!}

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Commits

Reviewing files that changed from the base of the PR and between 63a0fb9 and 0ffdfad.

Files selected for processing: 2

• src/a5/runtime/host_build_graph/aicore/resident_scheduler_impl.h
• tests/ut/cpp/a5/runtime/host_build_graph/test_hbg_gm_mix_startup.cpp

Files with no reviewable changes: 1

• src/a5/runtime/host_build_graph/aicore/resident_scheduler_impl.h

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