Debug a broken GRPO implementation with wrong grouping, wrong masks, and wrong old-logprob

Hard

Research Engineering & Debugging6 / 8

Chapter 256 / 8

Research Engineering & Debugging

Debug a broken GRPO implementation with wrong grouping, wrong masks, and wrong old-logprob

Hard

Debug a broken GRPO implementation with wrong grouping, wrong masks, and wrong old-logprobs.

Target interface

grpo_loss(logits, old_logprobs, actions, group_ids, rewards, completion_mask, eps=0.2)

Implement the function/class skeleton in the editor. Any correct approach is accepted.

Hints0 / 2

Reference solution

Your own code stays in the editor.

solution.pyPython

Local draft

import torch, torch.nn.functional as F

def grpo_loss(logits, old_logprobs, actions, group_ids, rewards, completion_mask, eps=0.2):
    raise NotImplementedError

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Chapter 256 / 8

Research Engineering & Debugging

Debug a broken GRPO implementation with wrong grouping, wrong masks, and wrong old-logprob

Hard

Debug a broken GRPO implementation with wrong grouping, wrong masks, and wrong old-logprobs.

Target interface

grpo_loss(logits, old_logprobs, actions, group_ids, rewards, completion_mask, eps=0.2)

Implement the function/class skeleton in the editor. Any correct approach is accepted.

Hints0 / 2

Reference solution

Your own code stays in the editor.