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A coarse-to-fine dynamic layer pruning framework for parameter-efficient fine-tuning

Zhang, Xin ; Li, Shuzhen LU ; Liu, Zhulin and Chen, C. L.Philip (2026) In Neurocomputing 698.
Abstract

The Parameter Efficient Fine-Tuning (PEFT) method freezes the original pre-trained model parameters and introduces a small number of trainable parameters from Adapter or LoRA to adapt models to downstream tasks. Current PEFT methods mainly enhance LLMs’ cross-task generalization through rigid pruning and global pruning strategies. However, these approaches suffer from coarse-grained adaptation and suboptimal efficiency in complex tasks and ultimately cause negative transfer in LLMs. To address this issue, this paper proposes a coarse-to-fine dynamic layer pruning framework for PEFT (CF-PEFT). Specifically, CF-PEFT first employs a gradient-free Broad Learning System (BLS) for initial layer classification based on task information gain... (More)

The Parameter Efficient Fine-Tuning (PEFT) method freezes the original pre-trained model parameters and introduces a small number of trainable parameters from Adapter or LoRA to adapt models to downstream tasks. Current PEFT methods mainly enhance LLMs’ cross-task generalization through rigid pruning and global pruning strategies. However, these approaches suffer from coarse-grained adaptation and suboptimal efficiency in complex tasks and ultimately cause negative transfer in LLMs. To address this issue, this paper proposes a coarse-to-fine dynamic layer pruning framework for PEFT (CF-PEFT). Specifically, CF-PEFT first employs a gradient-free Broad Learning System (BLS) for initial layer classification based on task information gain between adjacent layers. It quickly prunes task-agnostic layers to achieve coarse-grained efficient adaptation. It then devises parameter update magnitude-guided greedy strategy to progressively freeze task-specific layers to ensure fine-grained specialized adaptation. CF-PEFT strikes a better balance between task performance and parameter efficiency by gradient-free initialization and Coarse-to-Fine layer pruning strategy, which prevents performance degradation from rigid pruning and avoids the excessive computational cost from global pruning. Extensive experimental results demonstrate the effectiveness of CF-PEFT across tasks of varying-complexity and show its superior efficiency with only 0.03% training parameters in LLMs.

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; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Broad learning system, Gradient-free initialization, Layer pruning, Parameter efficient fine-tuning
in
Neurocomputing
volume
698
article number
134299
publisher
Elsevier
external identifiers
  • scopus:105042721038
ISSN
0925-2312
DOI
10.1016/j.neucom.2026.134299
language
English
LU publication?
yes
id
34429181-3cc3-4fa6-8eb6-b95a94022f6d
date added to LUP
2026-09-30 16:39:01
date last changed
2026-09-30 16:39:42
@article{34429181-3cc3-4fa6-8eb6-b95a94022f6d,
  abstract     = {{<p>The Parameter Efficient Fine-Tuning (PEFT) method freezes the original pre-trained model parameters and introduces a small number of trainable parameters from Adapter or LoRA to adapt models to downstream tasks. Current PEFT methods mainly enhance LLMs’ cross-task generalization through rigid pruning and global pruning strategies. However, these approaches suffer from coarse-grained adaptation and suboptimal efficiency in complex tasks and ultimately cause negative transfer in LLMs. To address this issue, this paper proposes a coarse-to-fine dynamic layer pruning framework for PEFT (CF-PEFT). Specifically, CF-PEFT first employs a gradient-free Broad Learning System (BLS) for initial layer classification based on task information gain between adjacent layers. It quickly prunes task-agnostic layers to achieve coarse-grained efficient adaptation. It then devises parameter update magnitude-guided greedy strategy to progressively freeze task-specific layers to ensure fine-grained specialized adaptation. CF-PEFT strikes a better balance between task performance and parameter efficiency by gradient-free initialization and Coarse-to-Fine layer pruning strategy, which prevents performance degradation from rigid pruning and avoids the excessive computational cost from global pruning. Extensive experimental results demonstrate the effectiveness of CF-PEFT across tasks of varying-complexity and show its superior efficiency with only 0.03% training parameters in LLMs.</p>}},
  author       = {{Zhang, Xin and Li, Shuzhen and Liu, Zhulin and Chen, C. L.Philip}},
  issn         = {{0925-2312}},
  keywords     = {{Broad learning system; Gradient-free initialization; Layer pruning; Parameter efficient fine-tuning}},
  language     = {{eng}},
  month        = {{10}},
  publisher    = {{Elsevier}},
  series       = {{Neurocomputing}},
  title        = {{A coarse-to-fine dynamic layer pruning framework for parameter-efficient fine-tuning}},
  url          = {{http://dx.doi.org/10.1016/j.neucom.2026.134299}},
  doi          = {{10.1016/j.neucom.2026.134299}},
  volume       = {{698}},
  year         = {{2026}},
}