Training Tensor Attention Efficiently: From Cubic to Almost Linear Time

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Cao, Yang, Liang, Yingyu, Shi, Zhenmei, Song, Zhao
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918302783111168
author Cao, Yang
Liang, Yingyu
Shi, Zhenmei
Song, Zhao
author_facet Cao, Yang
Liang, Yingyu
Shi, Zhenmei
Song, Zhao
contents Tensor Attention, a multi-view attention that is able to capture high-order correlations among multiple modalities, can overcome the representational limitations of classical matrix attention. However, the $O(n^3)$ time complexity of tensor attention poses a significant obstacle to its utilization in transformers, where $n$ is the input sequence length. In this work, we prove that the backward gradient of tensor attention training can be computed in almost linear time $n^{1+o(1)}$, the same complexity as its forward computation under the bounded entries assumption. We provide a closed-form solution for the gradient and propose a fast computation method utilizing polynomial approximation methods and tensor algebraic techniques. Furthermore, we prove the necessity and tightness of our assumption through hardness analysis, showing that slightly weakening it renders the gradient problem unsolvable in truly subcubic time. Our theoretical results establish the feasibility of efficient higher-order transformer training and may facilitate practical applications of tensor attention architectures.
format Preprint
id arxiv_https___arxiv_org_abs_2405_16411
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Training Tensor Attention Efficiently: From Cubic to Almost Linear Time
Cao, Yang
Liang, Yingyu
Shi, Zhenmei
Song, Zhao
Machine Learning
Artificial Intelligence
Computation and Language
Tensor Attention, a multi-view attention that is able to capture high-order correlations among multiple modalities, can overcome the representational limitations of classical matrix attention. However, the $O(n^3)$ time complexity of tensor attention poses a significant obstacle to its utilization in transformers, where $n$ is the input sequence length. In this work, we prove that the backward gradient of tensor attention training can be computed in almost linear time $n^{1+o(1)}$, the same complexity as its forward computation under the bounded entries assumption. We provide a closed-form solution for the gradient and propose a fast computation method utilizing polynomial approximation methods and tensor algebraic techniques. Furthermore, we prove the necessity and tightness of our assumption through hardness analysis, showing that slightly weakening it renders the gradient problem unsolvable in truly subcubic time. Our theoretical results establish the feasibility of efficient higher-order transformer training and may facilitate practical applications of tensor attention architectures.
title Training Tensor Attention Efficiently: From Cubic to Almost Linear Time
topic Machine Learning
Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2405.16411