arXiv Machine Learning

Recursive Sparse Attention: Million-Token Length Extrapolation at Logarithmic Cost

arXiv:2611. 07232v1 Announce Type: cross Abstract: At context lengths of about 1M tokens, dense attention is costly in prefill and decoding, and training typically relies on long documents, which become scarcer as the target length increases.

arXiv Machine Learning
Sep 11

HISA: Efficient Hierarchical Indexing for Fine-Grained Sparse Attention

HISA: Efficient Hierarchical Indexing for Fine-Grained Sparse Attention proposes a two-stage hierarchical indexer that replaces the flat token scan used in token-level sparse attention mechanisms like DeepSeek Sparse Attention. The method first performs block-level coarse filtering to discard irrelevant regions, then applies the original token-level indexer only within the retained candidate blocks, preserving the same top-sparse pattern for downstream attention. Benchmarks show HISA achieves significant speedups at 64K context and matches the quality of DeepSeek-V3.2 and GLM-5 without additional training.

By Yufei Xu, Fanxu Meng, Fan Jiang, Yuxuan Wang, Ruijie Zhou, Zhaohui Wang, Jiexi Wu, Zhixin Pan, Xiaojuan Tang, Wenjie Pei, Tongxuan Liu, Di Yin, Xing Sun, Muhan Zhang
arXiv AI
5d ago

Latent Sparse Attention: Towards Subquadratic Ultra-Long Context Attention

arXiv:2610.42147v1 Announce Type: new Abstract: Agentic workflows are increasingly shifting towards long-horizon tasks, such as open-ended scientific work, where models benefit from long context wind...

By Ales Kubicek, Andrea Caciolai, Liangzu Peng, Sukrit Sumant, Benjamin Hoover, Fraser Greenlee, Ruairidh M. Battleday, Radim Urban, Torsten Hoefler, James C. R. Whittington
arXiv AI
Oct 21

Stratified Sparse Attention: Reducing the Sparse-to-Dense Gap at Extreme Sparsity

The paper introduces Stratified Sparse Attention (SSA), a framework that blends deterministic top‑k retrieval with score‑guided sampling to reduce the gap between sparse and dense attention in large language models. SSA attends to high‑scoring tokens deterministically while sampling the remaining attention mass using proxy scores, thereby recovering more of the attention distribution. Experiments on benchmarks such as RULER, LongBench, LOFT, and AIME show that SSA outperforms existing sparse methods across models ranging from 3B to 27B parameters, achieving significant accuracy gains and up to 2.96× decode speedup with optimized CUDA kernels.

By Sahil Joshi, Prithvi Dixit, Aryan Katiyar, Agniva Chowdhury, Joseph E. Gonzalez, Anshumali Shrivastava, Aditya Desai, Kumar Krishna Agrawal
arXiv Computation and Language
5d ago

Subquadratic Attention with a Hierarchical Tree-Structured Indexer

The paper introduces Zyphra Hierarchical Attention (ZHA), a subquadratic sparse attention mechanism that uses a tree-structured indexer to compress key-value pairs and retrieve a sparse subset of keys during query time. By iteratively deepening the tree, ZHA achieves sublinear routing and attention costs, resulting in overall subquadratic scaling for long-context processing. The method can be applied to existing pretrained models with minimal distillation training, maintains performance on diverse evaluation tasks, and remains robust even with very deep trees.

By Leon Lufkin, Cutter Dawes, Alexander Speicher, Kamesh Krishnamurthy, Tom\'as Figliolia, Beren Millidge
arXiv Computation and Language
Oct 15

Joint Subspace Sparse Attention for Efficient Long-Context Decoding

Joint Subspace Sparse Attention (JSSA) is a new method that reduces KV‑cache traffic in long‑context LLM decoding by selecting tokens at the token level while preserving query–key structure. It learns a shared low‑dimensional query–key subspace through a tractable spectral solution and implements a gather‑free indexed‑attention kernel that supports per‑KV‑head selections. Across various attention architectures, JSSA maintains near full‑KV accuracy, avoids generation‑length inflation, and can achieve up to 6.43× decoding throughput on a single GPU for 128K context, even at 700B‑parameter scale.

By Jiwon Song, Yoongon Kim, Jae-Joon Kim
arXiv AI
Jun 12

MiniMax Sparse Attention

arXiv:2606. 13392v1 Announce Type: new Abstract: Ultra-long-context capability is becoming indispensable for frontier LLMs: agentic workflows, repository-scale code reasoning, and persistent memory all require the model to jointly attend over hundreds of thousands to millions of tokens, yet the quadratic cost of softmax attention makes this untenable at deployment scale.

By Xunhao Lai, Weiqi Xu, Yufeng Yang, Qiaorui Chen, Yang Xu, Lunbin Zeng, Xiaolong Li, Haohai Sun, Haichao Zhu, Vito Zhang, Pengyu Zhao