leavelet
b356773d2f
Addresses the opus review of the Step A/B compose stack: - FAIL FAST on symm + prefetcher coexistence: the MLA/index prefetchers issue their own per-span collectives and bypass the symm exchange, so letting them coexist would make COMPOSE_SYMM a silent no-op on every prefetch hit (measured "parity" that never ran). maybe_build_current_ page_writer_ranks now raises when a prefetcher is attached or SGLANG_CP_SHARED_KV_ENABLE_MLA_PREFETCH is set. - Arena parity now derives from a monotonic round epoch instead of raw layer_id: EAGLE draft layers reuse decoder layer ids, so id-parity would stop alternating halves (draft L0 -> next forward target L0 lands on the same half) and repeated-id rounds would keep appending into one half. begin_round(layer_id, kind) starts a new round (other half, offsets reset) when the id changes OR a kind repeats; regression test included. - Per-batch writer-ranks cache on the forward batch and a presence flag in the plan key: previously the ~bs x current-pages writer list was rebuilt AND tuple-hashed on every layer per call site, pure launch-path waste. - Rank-uniformity invariant documented at _symm_exchange_current_pages (any per-rank gate must go through a group agreement first) and an actionable arena-overflow message naming SGLANG_CP_SHARED_KV_SYMM_HEAP_MB. Deferred follow-ups (documented in the design doc): factor the two near- clone v2 helpers, single barrier per F-layer (~308us/batch), persistent device-side peer-ptr tables for the gather. 182 targeted tests + 8-rank GPU byte-exactness (v2 and symm) re-validated on g0034 syh-dev-new. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Registered Tests
Tests under this directory are auto-discovered by run_suite.py via CI registration decorators.
Where Should I Put My New Test?
No server / engine launch required
| What you're testing | Directory | Requires |
|---|---|---|
| Component logic in isolation (cache, scheduler, config, parser, etc.) | unit/<module>/ |
CPU or GPU |
| CUDA kernel correctness | kernels/ |
GPU |
Server / engine launch required (E2E)
| What you're testing | Directory | Requires |
|---|---|---|
| Model inference correctness | models/, 4-gpu-models/, 8-gpu-models/ |
GPU |
| Feature-specific (OpenAI API, LoRA, speculative, distributed, VLM, etc.) | openai_server/, lora/, spec/, distributed/, ... |
GPU |
| Benchmarks (performance, accuracy, stress) | benchmark/ |
GPU |
| Platform-specific | amd/, ascend/ |
Vendor GPU |
See unit/README.md for unit test conventions.