超越 K/V 缓存:混合线性注意力大语言模型中的跨模型状态交接
Beyond K/V Caches: Cross-Model State Handoff in Hybrid Linear-Attention LLMs
Jiacheng Cai, Tao Zhang, Siqi Liang, Yun Dai, Ziqian Zeng
AI 速读 基于摘要
针对混合线性注意力大模型在模型切换时需重复 prefill 的问题,提出同时迁移 FA 缓存、循环状态与卷积历史的 Hybrid State Transfer 方法。
cs.CL
查看原文摘要
Production deployments often use different models to balance cost and quality through cascading, routing, and switching models during long conversations. Context accumulates across turns. Each switch requires the target to repeat prefill over this context. Existing methods transfer full-attention (FA) K/V caches across models. Hybrid linear-attention models also retain recurrent states (REC) and convolution histories (Conv). The interaction between Conv and REC complicates cross-model state transfer. Conv perturbations can change keys and values in recurrent layers and alter REC updates. Conv histories are overwritten, but changes in REC can still affect later outputs. More accurate REC reconstruction need not improve continuation. Building on this, we propose Hybrid State Transfer (HST) for all three state types. It uses structured REC maps and preserves history order during Conv alignment. We calibrate the adapters using the frozen target's outputs during continuation. FA cache map updates are merged offline. Across five benchmarks, Qwen3.5 4B$\rightarrow$27B and 9B$\rightarrow$27B achieve mean task retentions of 89.88% and 94.11%, respectively. With source caches already available, separate timing on synthetic 16K inputs yields handoff body speedups of $21.66\times$ and $21.91\times$.