Step-by-step analysis walkthrough

Use when you own Fabric Contention Debug in a top-level integration review.

1. Open latest integration baseline and manifest.

2. Inspect failing metric by domain.

3. Trace first failing contract boundary.

4. Collect artifacts and assign single-thread owner.

5. Define minimal proof experiment.

6. Apply smallest reversible fix.

7. Run focused check then full regression.

8. Update dashboard and governance log.

9. Decide: close, waive with expiry, or escalate.

10. Publish final review memo.

Artifacts to collect

• congestion heatmap, transaction stall trace, arbiter audit report

• baseline manifest

• owner matrix

• regression summary

• risk memo

Decision memo template

SOC DECISION MEMO — Fabric Contention Debug
baseline:
metric:
root cause:
fix:
residual risk:
owners: performance lead, fabric owner, firmware owner

Reference visuals

Contention hotspot lens

FABRIC CONTENTION

traffic burst -> queue buildup -> VC starvation -> latency tail explosion
                          |
                     arbitration policy

SoC deep dive

Fabric correctness and contention behavior must be proven together.

Concept diagram

FABRIC FLOW
masters -> routers/VCs -> slaves + memory

Metric graph

LATENCY TAIL
p50 ███
p95 ██████
p99 ██████████

Reports and artifacts

• NoC contention heatmap

• ordering violation report

• QoS fairness summary

• protocol trace

Mini case study

Bandwidth looked fine at average load, but p99 tail violated SLA due to arbitration starvation.

Debug branches

• Isolate traffic class

• Check ordering assumptions

• Audit arbitration policy

Senior review question

Ask: what baseline, owner, and artifact prove this topic is truly closed?

Key takeaways

• State baseline manifest and owner with every closure metric.

• Run cross-domain regression after every top-level fix.

Common pitfalls

• Comparing results across different manifests.

• Unowned issues slipping through review cycles.

• Waiving risks without expiry and validation plan.

Principal SoC review addendum

Contention debug isolates head-of-line blocking, unfair arbitration, and backpressure loops before over-provisioning bus width or buffers.

Metric: contention hotspot recurrence, throughput collapse trigger