Function moe_grouped_decode_min_rows 

pub fn moe_grouped_decode_min_rows() -> usize

2026-09-25: Minimum rows for the grouped-GEMM MoE decode arm. The SSM stack (qwen3_ssm::trait_decode_multi_seq) and the attention layers’ multi-seq FFN both decide through moe_grouped_decode_for, so they share this width. The arm reads each routed expert once for all rows but first sorts and permutes the rows, a fixed cost that the threshold keeps off narrow batches.