pub const DECODE_ROLLBACK_RING_SLOTS: usize = 8;Expand description
Phase-C: number of boundary SSM-state snapshots retained per sequence in
the decode-rollback ring (hybrid GDN/Mamba models). DECOUPLED from
ROLLBACK_RESTEER_CAP: the cap bounds how many times we re-steer, but
the ring must retain enough boundary snapshots that a clean PRE-loop
boundary survives long enough to roll back to. Sizing it at the old
CAP + 1 = 3 meant a loop spanning ≥3 sentence/newline boundaries evicted
the clean boundary before the fuzzy detector (3 repeats) fired, forcing a
NoSsmSnapshot decline → hard-stop (observed: Claude-Code @ nvfp4-head,
2026-06-07). 8 covers the 3-repeat detector with margin at modest cost
(8 × max_batch × per-layer GDN state, allocated once). Pure-attention
models ignore this (their ring is 0; they roll back to any boundary).