APB: Accelerating Distributed Long-Context Inference by Passing Compressed Context Blocks across GPUs

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Huang, Yuxiang, Li, Mingye, Han, Xu, Xiao, Chaojun, Zhao, Weilin, Ao, Sun, Zhou, Hao, Zhou, Jie, Liu, Zhiyuan, Sun, Maosong
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912394063642624
author Huang, Yuxiang
Li, Mingye
Han, Xu
Xiao, Chaojun
Zhao, Weilin
Ao, Sun
Zhou, Hao
Zhou, Jie
Liu, Zhiyuan
Sun, Maosong
author_facet Huang, Yuxiang
Li, Mingye
Han, Xu
Xiao, Chaojun
Zhao, Weilin
Ao, Sun
Zhou, Hao
Zhou, Jie
Liu, Zhiyuan
Sun, Maosong
contents While long-context inference is crucial for advancing large language model (LLM) applications, its prefill speed remains a significant bottleneck. Current approaches, including sequence parallelism strategies and compute reduction through approximate attention mechanisms, still fall short of delivering optimal inference efficiency. This hinders scaling the inputs to longer sequences and processing long-context queries in a timely manner. To address this, we introduce APB, an efficient long-context inference framework that leverages multi-host approximate attention to enhance prefill speed by reducing compute and enhancing parallelism simultaneously. APB introduces a communication mechanism for essential key-value pairs within a sequence parallelism framework, enabling a faster inference speed while maintaining task performance. We implement APB by incorporating a tailored FlashAttn kernel alongside optimized distribution strategies, supporting diverse models and parallelism configurations. APB achieves speedups of up to 9.2x, 4.2x, and 1.6x compared with FlashAttn, RingAttn, and StarAttn, respectively, without any observable task performance degradation. We provide the implementation and experiment code of APB in https://github.com/thunlp/APB.
format Preprint
id arxiv_https___arxiv_org_abs_2502_12085
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle APB: Accelerating Distributed Long-Context Inference by Passing Compressed Context Blocks across GPUs
Huang, Yuxiang
Li, Mingye
Han, Xu
Xiao, Chaojun
Zhao, Weilin
Ao, Sun
Zhou, Hao
Zhou, Jie
Liu, Zhiyuan
Sun, Maosong
Machine Learning
Computation and Language
While long-context inference is crucial for advancing large language model (LLM) applications, its prefill speed remains a significant bottleneck. Current approaches, including sequence parallelism strategies and compute reduction through approximate attention mechanisms, still fall short of delivering optimal inference efficiency. This hinders scaling the inputs to longer sequences and processing long-context queries in a timely manner. To address this, we introduce APB, an efficient long-context inference framework that leverages multi-host approximate attention to enhance prefill speed by reducing compute and enhancing parallelism simultaneously. APB introduces a communication mechanism for essential key-value pairs within a sequence parallelism framework, enabling a faster inference speed while maintaining task performance. We implement APB by incorporating a tailored FlashAttn kernel alongside optimized distribution strategies, supporting diverse models and parallelism configurations. APB achieves speedups of up to 9.2x, 4.2x, and 1.6x compared with FlashAttn, RingAttn, and StarAttn, respectively, without any observable task performance degradation. We provide the implementation and experiment code of APB in https://github.com/thunlp/APB.
title APB: Accelerating Distributed Long-Context Inference by Passing Compressed Context Blocks across GPUs
topic Machine Learning
Computation and Language
url https://arxiv.org/abs/2502.12085