Paged and CP-ragged NSA indexer paths could materialize q x context fp32
MQA-logits buffers large enough to OOM high-cache-hit bs>1 prefill batches.
Port the syh branch chunking logic so paged and ragged paths split logits by
query rows when the estimated logits buffer exceeds the current free-memory
budget.
The free-memory query is cached on forward_batch so the OOM guard uses current
free memory without adding a torch.cuda.mem_get_info host sync on every layer.
The only new env kept from the syh commits is
SGLANG_NSA_MQA_LOGITS_CHUNK_FORCE_ROWS, which forces chunking for equivalence
validation.
Constraint: DeepGEMM fp8_mqa_logits still materializes fp32 logits internally, so limiting q rows is the least invasive way to cap peak memory
Rejected: Carry unrelated syh envs for page trace/source-fingerprint strictness | not part of the logits peak-memory fix
Rejected: Static mem_fraction-only budget | overestimates logits headroom shared with other forward activations
Confidence: medium
Scope-risk: moderate
Directive: Keep chunking row-split only; changing K/context partitioning needs topk_transform equivalence validation
Related: 40a0389a9c feat(nsa): chunk paged + CP-ragged MQA-logits by current-free-mem budget
Related: 108fa1f538 perf(nsa): cache MQA-logits free-mem budget per-forward
Tested: Local py_compile for environ.py and nsa_indexer.py
Tested: Remote g0034 cjy-glm5-new py_compile for environ.py and nsa_indexer.py
Not-tested: CUDA ETE run with forced SGLANG_NSA_MQA_LOGITS_CHUNK_FORCE_ROWS equivalence check
Not-tested: Full high-cache-hit bs>1 prefill OOM regression workload
Co-authored-by: OmX <omx@oh-my-codex.dev>
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