线性注意力研究者终于有了更精细的门控机制——Gated DeltaNet-2把擦除和写入分开控制，做高效长序列建模的团队可以直接复现并对比效果。
线性注意力模型通过固定大小的循环状态替代软注意力的无限缓存，但如何高效编辑压缩记忆而不打乱已有关联是难点。现有Delta规则模型使用单一标量门控同时控制擦除旧内容和写入新内容，存在耦合限制。Gated DeltaNet-2提出通道级擦除门控b_t和写入门控w_t，将两者解耦，可退化为KDA和Gated DeltaNet。在1.3B参数、100B FineWeb-Edu tokens训练下，该模型在语言建模、常识推理和检索任务上全面超越Mamba-2、Gated DeltaNet、KDA和Mamba-3。尤其在长上下文RULER基准的多键检索设置中优势显著，代码已开源。
Gated DeltaNet-2: Decoupling Erase and Write in Linear Attention
Linear attention replaces the unbounded cache of softmax attention with a fixed-size recurrent state, reducing sequence mixing to linear time and decoding to constant memory. The hard part is not just what to forget, but how to edit this compressed memory without scrambling existing associations. Delta-rule models subtract the current read before writing a new value, and Kimi Delta Attention (KDA) sharpens forgetting with channel-wise decay. But the active edit still uses a single scalar gate to control two different things: how much old content to erase on the key side and how much new content to commit on the value side. We introduce Gated DeltaNet-2, which generalizes both Gated DeltaNet and KDA by inheriting adaptive forgetting and channel-wise decay while addressing their shared limitation, the scalar tie between erasing and writing. Gated Delta Rule-2 separates these roles with a channel-wise erase gate b_t and a channel-wise write gate w_t, reducing to KDA when both gates collapse to the same scalar and to Gated DeltaNet when the decay also collapses. We derive a fast-weight update view, a chunkwise WY algorithm with channel-wise decay absorbed into asymmetric erase factors, and a gate-aware backward pass that preserves efficient parallel training. At 1.3B parameters trained on 100B FineWeb-Edu tokens, Gated DeltaNet-2 achieves the strongest overall results among Mamba-2, Gated DeltaNet, KDA, and Mamba-3 variants across language modeling, commonsense reasoning, and retrieval. Its advantage is most pronounced on long-context RULER needle-in-a-haystack benchmarks, where it improves the evaluated multi-key retrieval setting and remains strong in both recurrent and hybrid settings. Code is available at https://github.com/NVlabs/GatedDeltaNet-2.