long context

Follow the running maximum and weighted sum across attention tiles, with executable arithmetic and an honest memory-traffic comparison.

Longer sequences exercise more state updates, different boundaries and sometimes different kernel paths. Use a two-tile example to check online softmax, then test masking, indexing and precision against a stable reference.

Trace a causal query across local and remote KV blocks. Separate sequence and context sharding, count one concrete tensor, and avoid dividing memory twice.

Calculate retained cache and prefill work for a stated 128k model shape, then choose scheduling and memory policies from measured limits.

A context-window limit is not a latency or concurrency guarantee. Budget retained state, prefill and shared service time; distinguish cache reuse from eliminating work; choose isolation only when measured interference justifies its cost.

Define cold and reused-context objectives, verify the checkpoint's real state layout, and size per-rank memory and transfer demand. Caching and phase separation help only when their compatibility, retention and capacity assumptions hold.