Update: select A5 cluster ownership from trusted topology

[yanghaoran29]

Summary

• Select balanced contiguous AICore cluster ownership when live CPU_TOPO or a verified JSON fallback fully matches the device OCCUPY pool.
• Preserve round-robin ownership for incomplete, unavailable, or unmatched topology.
• Carry the internal mode through both A5 runtimes and cover topology selection and partition boundaries.

Testing

• test_a5_aicpu_topology_fallback
• Syntax checks for both A5 scheduler cold paths
• clang-format --dry-run --Werror and git diff --check
• Onboard hardware validation (not run)

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📥 Commits

Reviewing files that changed from the base of the PR and between a1aa7fd and 8de8fed.

📒 Files selected for processing (14)

• src/a5/docs/hardware.md
• src/a5/platform/include/common/scheduler_cluster_partition.h
• src/a5/platform/onboard/host/aicpu_topology_probe.cpp
• src/a5/platform/onboard/host/aicpu_topology_probe.h
• src/a5/platform/onboard/host/device_runner.cpp
• src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_cold_path.cpp
• src/a5/runtime/host_build_graph/runtime/scheduler/scheduler_context.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/runtime.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/scheduler_cold_path.cpp
• src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/scheduler_context.h
• src/a5/runtime/tensormap_and_ringbuffer/runtime/shared/runtime.cpp
• src/common/host_build_graph/runtime.h
• src/common/host_build_graph/shared/runtime.cpp
• tests/ut/cpp/a5/test_aicpu_topology_fallback.cpp

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📝 Walkthrough

Walkthrough

The change adds topology-aware scheduler cluster assignment. Validated topology selects contiguous ownership. Other topology states retain round-robin ownership. Runtime state, scheduler paths, diagnostics, tests, and hardware documentation now support both modes.

Changes

Scheduler cluster assignment

Layer / File(s)	Summary
Partition policy contract src/a5/platform/include/common/scheduler_cluster_partition.h	Defines round-robin and contiguous assignment modes, cluster ranges, ownership helpers, and invalid-input behavior.
Topology validation and selection src/a5/platform/onboard/host/aicpu_topology_probe.*, src/a5/platform/onboard/host/device_runner.cpp, tests/ut/cpp/a5/test_aicpu_topology_fallback.cpp, src/a5/docs/hardware.md	Validates topology coverage, selects contiguous or round-robin assignment, publishes the result to runtime, logs the mode, and tests the selection rules.
Runtime assignment propagation src/a5/runtime/tensormap_and_ringbuffer/runtime/*, src/common/host_build_graph/runtime.*	Adds runtime storage, launch-descriptor state, default initialization, and assignment accessors.
Scheduler ownership integration src/a5/runtime/host_build_graph/runtime/scheduler/*, src/a5/runtime/tensormap_and_ringbuffer/runtime/scheduler/*	Uses the configured assignment for ownership, ranges, handshaking, diagnostics, cluster traversal, and assignment logging.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Merge Risk: ⚪ Minimal · up to 8de8f

A5 scheduler ownership now uses balanced contiguous cluster ranges only for validated topology and preserves round-robin ownership for invalid or incomplete topology. The current change is ready to merge.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 35.56% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 45 functions across 13 files. (1 skipped:…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the main change: selecting A5 cluster ownership from trusted topology.
Description check	✅ Passed	The description directly explains topology-based contiguous assignment, round-robin fallback behavior, runtime propagation, and testing.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 35.56% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 45 functions across 13 files. (1 skipped: 1 unsupported.)

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_{I twitch my nose at clusters bright
Contiguous hops now land just right
Round-robin guards the uncertain trail
Runtime carries the chosen tale
Tiny tests confirm each rail}

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