arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2602.22495cs.LGcs.AI

面向LLM推理的强化学习感知知识蒸馏

Reinforcement-aware Knowledge Distillation for LLM Reasoning

Meta;Guo et al.;Lin et al.;Xu et al.;Shao et al.;Schulman et al.;Xie et al.

Zhaoyang Zhang, Shuli Jiang, Yantao Shen, Yuting Zhang, Dhananjay Ram, Shuo Yang, Zhuowen Tu, Wei Xia, Stefano Soatto

AI总结:

提出RL感知蒸馏(RLAD),通过信任区域比率蒸馏(TRRD)在强化学习后训练中实现选择性模仿,解决分布不匹配和目标干扰问题,在逻辑推理和数学基准上优于现有方法。

摘要:

强化学习(RL)后训练最近推动了长链思维推理大语言模型(LLM)的重大进展,但这类模型的高推理成本促使将其蒸馏到更小的学生模型中。大多数现有的知识蒸馏(KD)方法是为监督微调(SFT)设计的,依赖于固定的教师轨迹或基于教师-学生KL散度的正则化。当与RL结合时,这些方法常常遭受分布不匹配和目标干扰:教师监督可能与学生不断变化的rollout分布不一致,并且KL正则化项可能与奖励最大化竞争,需要仔细的损失平衡。为了解决这些问题,我们提出了RL感知蒸馏(RLAD),它在RL期间执行选择性模仿——仅在改进当前策略更新时引导学生向教师学习。我们的核心组件,信任区域比率蒸馏(TRRD),用基于PPO/GRPO风格似然比的目标替代教师-学生KL正则化项,该目标锚定到教师-旧策略混合,从而在学生rollout上产生优势感知、信任区域约束的蒸馏,并自然平衡探索、利用和模仿。在多种逻辑推理和数学基准上,RLAD始终优于离线蒸馏、标准GRPO和基于KL的在策略教师-学生知识蒸馏。

英文摘要:

Reinforcement learning (RL) post-training has recently driven major gains in long chain-of-thought reasoning large language models (LLMs), but the high inference cost of such models motivates distillation into smaller students. Most existing knowledge distillation (KD) methods are designed for supervised fine-tuning (SFT), relying on fixed teacher traces or teacher-student Kullback-Leibler (KL) divergence-based regularization. When combined with RL, these approaches often suffer from distribution mismatch and objective interference: teacher supervision may not align with the student's evolving rollout distribution, and the KL regularizer can compete with reward maximization and require careful loss balancing. To address these issues, we propose RL-aware distillation (RLAD), which performs selective imitation during RL -- guiding the student toward the teacher only when it improves the current policy update. Our core component, Trust Region Ratio Distillation (TRRD), replaces the teacher-student KL regularizer with a PPO/GRPO-style likelihood-ratio objective anchored to a teacher--old-policy mixture, yielding advantage-aware, trust-region-bounded distillation on student rollouts and naturally balancing exploration, exploitation, and imitation. Across diverse logic reasoning and math benchmarks, RLAD consistently outperforms offline distillation, standard GRPO, and KL-based on-policy teacher-student knowledge distillation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑