Disentangling Task Conflicts in Multi-Task LoRA via Orthogonal Gradient Projection

Fuente: arXiv
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Autori principali: Yang, Ziyu, Chen, Guibin, Yang, Yuxin, Zeng, Aoxiong, Yang, Xiangquan
Natura: Preprint
Pubblicazione: 2026
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author Yang, Ziyu
Chen, Guibin
Yang, Yuxin
Zeng, Aoxiong
Yang, Xiangquan
author_facet Yang, Ziyu
Chen, Guibin
Yang, Yuxin
Zeng, Aoxiong
Yang, Xiangquan
contents Multi-Task Learning (MTL) combined with Low-Rank Adaptation (LoRA) has emerged as a promising direction for parameter-efficient deployment of Large Language Models (LLMs). By sharing a single adapter across multiple tasks, one can significantly reduce storage overhead. However, this approach suffers from negative transfer, where conflicting gradient updates from distinct tasks degrade the performance of individual tasks compared to single-task fine-tuning. This problem is exacerbated in LoRA due to the low-rank constraint, which limits the optimization landscape's capacity to accommodate diverse task requirements. In this paper, we propose Ortho-LoRA, a gradient projection method specifically tailored for the bipartite structure of LoRA. Ortho-LoRA dynamically projects conflicting task gradients onto the orthogonal complement of each other within the intrinsic LoRA subspace. Extensive experiments on the GLUE benchmark demonstrate that Ortho-LoRA effectively mitigates task interference, outperforming standard joint training and recovering 95\% of the performance gap between multi-task and single-task baselines with negligible computational overhead.
format Preprint
id arxiv_https___arxiv_org_abs_2601_09684
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Disentangling Task Conflicts in Multi-Task LoRA via Orthogonal Gradient Projection
Yang, Ziyu
Chen, Guibin
Yang, Yuxin
Zeng, Aoxiong
Yang, Xiangquan
Machine Learning
Artificial Intelligence
Computation and Language
Multi-Task Learning (MTL) combined with Low-Rank Adaptation (LoRA) has emerged as a promising direction for parameter-efficient deployment of Large Language Models (LLMs). By sharing a single adapter across multiple tasks, one can significantly reduce storage overhead. However, this approach suffers from negative transfer, where conflicting gradient updates from distinct tasks degrade the performance of individual tasks compared to single-task fine-tuning. This problem is exacerbated in LoRA due to the low-rank constraint, which limits the optimization landscape's capacity to accommodate diverse task requirements. In this paper, we propose Ortho-LoRA, a gradient projection method specifically tailored for the bipartite structure of LoRA. Ortho-LoRA dynamically projects conflicting task gradients onto the orthogonal complement of each other within the intrinsic LoRA subspace. Extensive experiments on the GLUE benchmark demonstrate that Ortho-LoRA effectively mitigates task interference, outperforming standard joint training and recovering 95\% of the performance gap between multi-task and single-task baselines with negligible computational overhead.
title Disentangling Task Conflicts in Multi-Task LoRA via Orthogonal Gradient Projection
topic Machine Learning
Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2601.09684