Papers › CPPO: Accelerating the Training of Group Relative Policy Optimization-Based Reasoning Models

CPPO: Accelerating the Training of Group Relative Policy Optimization-Based Reasoning Models

28 Mar 2025arXiv:2503.22342archive 2025-07-28

Zhihang Lin, Mingbao Lin, Yuan Xie, Rongrong Ji

This paper introduces Completion Pruning Policy Optimization (CPPO) to accelerate the training of reasoning models based on Group Relative Policy Optimization (GRPO). GRPO, while effective, incurs high training costs due to the need for sampling multiple completions for each question. Our experiment and theoretical analysis reveals that the number of completions impacts model accuracy yet increases training time multiplicatively, and not all completions contribute equally to policy training -- their contribution depends on their relative advantage. To address these issues, we propose CPPO, which prunes completions with low absolute advantages, significantly reducing the number needed for gradient calculation and updates. Additionally, we introduce a dynamic completion allocation strategy to maximize GPU utilization by incorporating additional questions, further enhancing training efficiency. Experimental results demonstrate that CPPO achieves up to 8.32× speedup on GSM8K and 3.51× on Math while preserving or even enhancing the accuracy compared to the original GRPO. We release our code at https://github.com/lzhxmu/CPPO.

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extract_answer_from_model_output lzhxmu/cppo/cppo_verl/recipe/cppo/src/gsm8k_compute_score.py official repository ran fingerprinted Apache-2.0 (permissive) · 6859aa3f82a38002 · report
extract_last_number lzhxmu/cppo/cppo_verl/recipe/cppo/src/gsm8k_compute_score.py official repository ran fingerprinted Apache-2.0 (permissive) · 0014331dab98c0a5 · report
extract_single_number lzhxmu/cppo/cppo_verl/recipe/cppo/src/gsm8k_compute_score.py official repository ran fingerprinted Apache-2.0 (permissive) · 6036741237b33141 · report
get_custom_reward_fn lzhxmu/cppo/cppo_verl/recipe/cppo/src/main_cppo.py official repository ran · our draft was wrong Apache-2.0 (permissive) · 34be00218891a21a · report
get_huggingface_actor_config lzhxmu/cppo/cppo_verl/verl/utils/model.py official repository ran Apache-2.0 (permissive) · fe79c459a3e4cc64 · report
union_tensor_dict lzhxmu/cppo/cppo_verl/verl/protocol.py official repository ran · fixture could not drive it Apache-2.0 (permissive) · 21331a58f93375e4 · report
unpad_dataproto lzhxmu/cppo/cppo_verl/verl/protocol.py official repository ran · our draft was wrong Apache-2.0 (permissive) · 25f0ea3f460f6ce1 · report
extract_solution lzhxmu/cppo/cppo_verl/recipe/cppo/precess_gsm8k.py official repository unverified Apache-2.0 (permissive) · e4128a6f1b0585bc · report
get_generation_config lzhxmu/cppo/cppo_verl/verl/utils/model.py official repository unverified Apache-2.0 (permissive) · 660713a8fa047736 · report
get_weight_loader lzhxmu/cppo/cppo_verl/verl/models/weight_loader_registry.py official repository unverified Apache-2.0 (permissive) · 39fba8c5b01d595e · report
get_weight_saver lzhxmu/cppo/cppo_verl/verl/models/weight_loader_registry.py official repository unverified Apache-2.0 (permissive) · 8bf1b3e9bf87072c · report
load_state_dict_to_megatron_gptmodel lzhxmu/cppo/cppo_verl/verl/models/mcore/loader.py official repository unverified Apache-2.0 (permissive) · 1901b047ab8e1654 · report
squeeze lzhxmu/cppo/cppo_verl/verl/utils/model.py official repository unverified Apache-2.0 (permissive) · 3b15e2ac7497c441 · report

Tasks

GSM8KMath

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Methods

Pruning

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