Fabric Contention Debug: Review Checklist

Review checklist

Review Checklist for Fabric Contention Debug focuses on contention hotspot recurrence, throughput collapse trigger. The goal is to map symptoms to boundary contracts, owner actions, and regression-proof closure.

• Baseline manifest and revision are explicit.

• Boundary contracts for this topic are current and approved.

• Ownership map covers all open issues.

• Focused and full regression evidence both exist.

• Residual risks are either closed or bounded via waiver policy.

• Owners signed: performance lead, fabric owner, firmware owner.

Signoff ownership

OWNERSHIP MAP — Fabric Contention Debug

artifact             owner
-----------------    -----------------
primary owner     performance lead
co-owner          fabric owner
review owner      firmware owner

No top-level issue should remain ownerless beyond one review cycle.

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