fix(vime): avoid double temperature scaling for reused logits

[inaniloquentee]

Summary

• avoid applying rollout temperature twice for legacy VIME requests that reuse pre-scaled local logits
• preserve one temperature application for current VIME requests with unscaled local logits
• keep hidden-state recomputation on the original request temperature
• add numerical regression coverage for both real VIME contracts at temperature 0.7
• change RL-Kernel only; no VIME source changes

Contract details

The PR #400 experiment pins VIME commit c80200e. That revision divides request.logits by rollout_temperature before provider dispatch and sets metadata["logits_are_temperature_scaled"] = True. Reapplying request.temperature in RL-Kernel therefore turns 0.7 into an effective 0.49.

VIME PRs #423 and #424 use the newer contract: provider-bound logits remain unscaled, the metadata marker is absent, and request.temperature must still be applied once. This change supports both contracts. The marker is consumed only by the reused-local-logits path; hidden-state recomputation continues to use the request temperature.

Validation

• python -m pytest -q tests/test_vime_linear_logp_provider.py: 10 passed
• Black, isort, Flake8, and git diff --check passed for the changed files
• patched PR docs(rocm): publish G10/G11 200-step RL results #400 G11 strict run: first 4,165 tokens had mismatch count 0 and max absolute logp diff 0.0

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: d8c96ba9-56e8-4a5a-b5f9-511ad9e4a6a4

📥 Commits

Reviewing files that changed from the base of the PR and between c5836d3 and 06b6e1f.

📒 Files selected for processing (2)

• rl_engine/integrations/vime/linear_logp_provider.py
• tests/test_vime_linear_logp_provider.py

🚧 Files skipped from review as they are similar to previous changes (1)

• rl_engine/integrations/vime/linear_logp_provider.py

Included review availability: Your plan provides up to 2 included reviews per hour; 0 remain after this review.

---

📝 Walkthrough

Walkthrough

The strict Vime provider now resolves local-logit temperature from scaling metadata. Reused pre-scaled logits skip further scaling, while hidden-logit recomputation still uses the request temperature. Tests verify both paths.

Changes

Vime local-logit temperature handling

Layer / File(s)	Summary
Resolve and apply local-logit temperature rl_engine/integrations/vime/linear_logp_provider.py	The strict path returns None when local logits are marked as temperature-scaled. Otherwise, it uses the request temperature for entropy checks and from_local_logits.
Validate temperature handling tests/test_vime_linear_logp_provider.py	Tests verify single temperature application for pre-scaled and unscaled logits. A separate test confirms that hidden-logit recomputation still receives the request temperature. Formatting-only edits do not change test behavior.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Merge Risk: ⚪ Minimal · up to 06b6e

The updated strict-provider paths and their regression coverage consistently preserve single temperature application for reused logits while retaining scaling for hidden-state recomputation. The change is ready to merge.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 12 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the primary change: preventing double temperature scaling for reused logits in VIME.

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 2

📝 Generate docstrings 💡

• Commit to this branch
• Create a new PR

🛠️ Fix failing CI checks 💡

• Commit to this branch
• Create a new PR

🧪 Generate unit tests (beta)

• Commit to this branch
• Create a new PR

---

_{Comment @coderabbitai help to get the list of available commands.}

[Flink-ddd]

LGTM

[maxiaosong1124]

LGTM!