BIPEFT: Budget-Guided Iterative Search for Parameter Efficient Fine-Tuning of Large Pretrained Language Models
Aofei Chang, Jiaqi Wang, Han Liu, Parminder Bhatia, Cao Xiao, Ting Wang, Fenglong Ma
TL;DR
BIPEFT addresses the cost and inefficiency of fine-tuning large language models by automatically designing PEFT configurations under a parameter budget. It introduces a budget-guided iterative search that disentangles binary module existence from rank-dimension searches, with budget-aware early stopping and adaptive selection for both modules and dimensions. The method relies on a differential NAS framework using two interconnected architecture spaces and a Gumbel-Softmax-based optimization, achieving strong performance on GLUE and SuperGLUE with substantially reduced search costs. BIPEFT demonstrates superior efficiency and generalization, offering a practical solution for scalable PEFT in real-world downstream tasks.
Abstract
Parameter Efficient Fine-Tuning (PEFT) offers an efficient solution for fine-tuning large pretrained language models for downstream tasks. However, most PEFT strategies are manually designed, often resulting in suboptimal performance. Recent automatic PEFT approaches aim to address this but face challenges such as search space entanglement, inefficiency, and lack of integration between parameter budgets and search processes. To overcome these issues, we introduce a novel Budget-guided Iterative search strategy for automatic PEFT (BIPEFT), significantly enhancing search efficiency. BIPEFT employs a new iterative search strategy to disentangle the binary module and rank dimension search spaces. Additionally, we design early selection strategies based on parameter budgets, accelerating the learning process by gradually removing unimportant modules and fixing rank dimensions. Extensive experiments on public benchmarks demonstrate the superior performance of BIPEFT in achieving efficient and effective PEFT for downstream tasks with a low parameter budget.
