L1 Cache & Texture Path: Review Checklist

Review checklist

Review Checklist for L1 Cache & Texture Path centers on L1 hit rate, texture cache efficiency, and cache-thrashing incidents. The objective is to connect profiler evidence to root-cause mechanism and release-safe action.

• Workload scope and target KPI are explicitly documented.

• Profiler + counter evidence is reproducible with revision tags.

• Bottleneck classification is proved with mechanism-level traces.

• Mitigation includes owner, blast radius, and rollback criteria.

• End-to-end benchmark matrix confirms closure.

• Owners signed: memory system lead, graphics architect, driver team.

Signoff ownership

GPU OWNERSHIP LAYERS — L1 Cache & Texture Path

artifact area     owner
----------------  ----------------------------
architecture    memory system lead
RTL/microarch   graphics architect
software/tools  driver team

Rule: each metric needs a named owner before signoff.

GPU deep dive

Bandwidth wins come from coalescing and locality discipline, not peak-memory specs alone.

Concept diagram

MEMORY HIERARCHY

register -> shared/L1 -> L2/LLC -> HBM/GDDR
access pattern quality decides latency

Metric graph

BANDWIDTH UTILIZATION

requested BW  ███████████
effective BW  ████████
wasted BW     ███

Reports and artifacts

• L1/L2 hit-rate report

• HBM efficiency counters

• coalescing transaction log

• shared-memory bank audit

Mini case study

Stencil kernel sat at 43% of peak HBM due to uncoalesced loads; layout rewrite recovered 1.6x effective bandwidth.

Debug branches

• Check transactions per request at warp granularity

• Classify cache-thrash versus true DRAM saturation

• Audit shared-memory bank conflicts before algorithm rewrites

Senior review question

Ask: which metric and benchmark pairing proves this topic is truly closed in production context?

Key takeaways

• Always pair micro-kernel metrics with end-to-end workload impact.

• Lock toolchain, driver, and launch metadata before comparing performance results.

Common pitfalls

• Optimizing occupancy without checking memory-system saturation.

• Comparing profiler captures from different driver or compiler builds.

• Declaring wins without reproducible accuracy and performance gates.

Review checklist explanation

A checklist is not bureaucracy here; it is how GPU teams avoid confusing local wins with product wins. Every signoff item should protect against a known class of false confidence.

For L1 Cache & Texture Path, the minimum checklist is workload scope, L1 hit rate, texture cache efficiency, and cache-thrashing incidents, artifact evidence (cache hit/miss profile, access stride study, and texture-path latency report), bottleneck classification, owner, rollback path, and full matrix validation.

If the change affects architecture or RTL, include correctness and PPA evidence. If it affects compiler/runtime policy, include compatibility and deployment evidence. If it affects physical design, include timing, IR, thermal, and observability evidence.