Phase 2 prepare_receive allocates kv_pool slots that aren't visible
to radix / session bookkeeping until finalize_ingest. Without this
fix, the scheduler's idle self_check fires:
ValueError: token_to_kv_pool_allocator memory leak detected!
available=288391, evictable=5, protected=0, session_held=0
(expected sum == 288460)
_check_radix_cache_memory now subtracts
sum(len(rec.slot_indices) for rec in ctrl._ingest_records.values())
from the expected total before flagging a leak. Snapshot_reserved is
also printed in the leak message for diagnostics.
Smoke confirmed (scripts/smoke_snapshot_sglang_integration.py):
[smoke] prepare_receive on P → 200: ok=true (96 layer bufs)
[smoke] dump on D → 200: ok=false, reason=session-not-resident
[smoke] finalize on P → 200: ok=true, inserted_prefix_len=0
[smoke] OVERALL: PASS
End-to-end KV-correctness (snapshot ingest yields cache hit on next
prefill) still requires the agentic+router stack — covered in the E4
sweep, not this smoke.
a369722efe