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name: expert-cache description: "Debug and extend mixtral-offloading's MoE expert cache, storage wrapper, and sparse routing internals." metadata: disco-role: operating disable-model-invocation: true license: MIT

Expert Cache

Use this sub-skill when the task is about expert offloading internals rather than simply running the demo: ExpertCache, MixtralExpertWrapper, SparseMoeWrapper, expert UIDs, LRU eviction groups, pinned offload storage, or cache-capacity errors.

Read this when

• The user sees Cache is full, No evictable experts, already loading experts, duplicate expert UID assertions, or eviction-group assertions.
• The task is to change offloading policy, add prefetching, debug storage movement, or inspect sparse MoE routing.
• The user wants to understand how offload_per_layer becomes main_size and offload_size inside ExpertCache.

Route map

1. Read references/expert-cache-api.md for ExpertInfo, EvictionGroupInfo, ExpertCache, and method invariants.
2. Read references/storage-and-routing.md for MixtralExpertWrapper storage replacement and SparseMoeWrapper.forward routing flow.
3. Use scripts/inspect_cache_plan.py to compute cache capacities and example expert UIDs without loading model weights.
4. Read references/troubleshooting.md for capacity, reentrancy, storage, pinned-memory, and routing-shape failures.

What this sub-skill owns

• Expert-cache capacity and eviction invariants.
• Expert UID layout and eviction-group behavior.
• Storage wrapping and state-dict storage hooks.
• Sparse MoE top-k routing through cached experts.

What to route elsewhere

• Use ../inference-workflow/SKILL.md for full model construction, generation, and offload config selection.
• Use ../quantization-kernels/SKILL.md for HQQ quantized MLP layers, packing, and Triton kernel failures.

Safe verification

Most cache internals require real MixtralExpertWrapper objects backed by CUDA UntypedStorage. For safe planning, use the bundled script and source/API reasoning. Do not construct the full cache with dummy objects unless their storage type, size, and device match the expected wrapper invariants.