EBS: Efficient Block-Sparse Framework for Continual Learning of Large Language Models

Zhixin Han, Hang Gao, Yinhao Bai, Yuhua Zhao, Bitong Luo, Zhiyu li, Mengting Hu, Minlie Huang


Abstract
By continuously acquiring new knowledge, continual learning enables large language models (LLMs) to remain adaptive, accurate, and relevant as the world evolves. In continual learning, tasks arrive one after another and the model learns them sequentially. As more tasks are introduced, existing methods for learning a new task impose increasing computational demands. However, we find that the computational overhead, which gradually increases as the number of tasks grows, can be mitigated. To limit the continual increase in computational costs, we introduce a simple but efficient block-sparse (EBS) framework for continual learning of LLMs. In EBS, we employ a dedicated, task-specific low-rank adaptation (LoRA) block for each task. When training on a new task, only one LoRA block is loaded into GPU memory and involved in computation, while at inference each input activates at most two LoRA blocks. This design ensures that the computational cost remains independent of the number of tasks, allowing EBS to maintain high efficiency even when the sequence of tasks becomes very large. We offer a simple implementation that works across different model sizes and transformer architectures (decoder-only and encoder-decoder) while consistently delivering both high efficiency and strong task performance. Experimental results on two continual learning benchmarks demonstrate that EBS achieves state-of-the-art performance on the T5 and LLaMA 2 models.
Anthology ID:
2026.findings-emnlp.2462
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
52983–52993
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2462/
DOI:
Bibkey:
Cite (ACL):
Zhixin Han, Hang Gao, Yinhao Bai, Yuhua Zhao, Bitong Luo, Zhiyu li, Mengting Hu, and Minlie Huang. 2026. EBS: Efficient Block-Sparse Framework for Continual Learning of Large Language Models. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 52983–52993, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
EBS: Efficient Block-Sparse Framework for Continual Learning of Large Language Models (Han et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2462.pdf