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3A大作!阿里ROLL团队从基建->算法->机理,推动RL4LLM全栈协同优化
机器之心· 2025-11-10 04:40
Core Insights - The article discusses the launch of the "3A" collaborative optimization framework by Alibaba's ROLL team, which includes Async Architecture, Asymmetric PPO, and Attention Mechanism, aimed at enhancing Reinforcement Learning for Large Language Models (RL4LLM) [1][2][5] Group 1: Async Architecture - ROLL Flash is introduced as a high-performance RL training system that utilizes asynchronous design to maximize resource utilization and accelerate large-scale RL training [5][11] - The core principle of ROLL Flash is decoupling, which allows for fine-grained parallelism and sampling-training decoupling, leading to a fully pipelined execution of generation, environment interaction, reward calculation, and model training [12][13] - ROLL Flash has demonstrated significant performance improvements across various mainstream RL tasks, achieving nearly linear scalability with a hundred-card scale [16][25] Group 2: Asymmetric PPO - Asymmetric Proximal Policy Optimization (AsyPPO) is introduced as a lightweight variant of PPO that shows that the size of the critic does not necessarily correlate with its value estimation capability [45][48] - The research indicates that only two small critics are sufficient to achieve comparable or even superior value estimation performance, reducing the need for expensive computational resources [51][53] - AsyPPO introduces two key innovations: diversified micro-critic aggregation and uncertainty-aware policy loss reconstruction, enhancing training stability and efficiency [55][58] Group 3: Attention Mechanism - The article redefines the role of attention in language models, suggesting it serves as a structured blueprint that reveals the internal logic of model reasoning [2][64] - By analyzing attention dynamics, the framework aims to align the optimization objectives with the model's inherent reasoning rhythm, leading to improved training efficiency and interpretability [67][68] - The research proposes a refined credit allocation strategy based on attention signals, allowing for more effective reinforcement learning by focusing on critical reasoning steps [82][86]