[https://nvbugs/6250866][fix] Fix deep ep partial warp sync for gptoss shapes

[dongfengy]

NOTE: This ensure partial warp sync is fine.

[NVBUG-6250866][bugfix] wire DeepEP patch into FetchContent

Summary by CodeRabbit

• Bug Fixes
  • Applied a fix to GPU kernel synchronization to improve stability and correctness of deep learning computations.

Description

Test Coverage

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[coderabbitai]

📝 Walkthrough

Walkthrough

The PR registers a CUDA kernel synchronization fix for the deep_ep third-party dependency. The fetch configuration now references a new patch file that replaces bare warp synchronization calls with active-mask-aware variants to handle the case where the final tile contains fewer lanes than a full warp.

Changes

CUDA Synchronization Fix for deep_ep

Layer / File(s)	Summary
Patch configuration and intranode synchronization fix 3rdparty/fetch_content.json, 3rdparty/patches/deep_ep_intranode_combine_fix.patch	The deep_ep_download entry in fetch_content.json is updated to register patches/deep_ep_intranode_combine_fix.patch for automatic application. The patch replaces __syncwarp() with __syncwarp(__activemask()) at TMA wait, fence, and final synchronization points in intranode.cu, ensuring only active warp lanes participate when the final tile has a subset of lanes.

🎯 2 (Simple) | ⏱️ ~12 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The PR description lacks essential details required by the template, with only a brief note and title but missing implementation explanation and test coverage information.	Fill in the Description section explaining the issue being fixed and the solution approach, and detail relevant tests that validate the warp synchronization fix.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.
Title check	✅ Passed	The title clearly describes the main change: fixing partial warp synchronization in Deep EP for GPT-OSS shapes, which is the core issue addressed by the patch to intranode.cu and the FetchContent configuration update.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

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[dongfengy]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #52176 [ run ] triggered by Bot. Commit: ec4d1f3 Link to invocation

[tensorrt-cicd]

PR_Github #52176 [ run ] completed with state SUCCESS. Commit: ec4d1f3
/LLM/main/L0_MergeRequest_PR pipeline #41496 completed with status: 'FAILURE'

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[dongfengy]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #52254 [ run ] triggered by Bot. Commit: 1df8987 Link to invocation

[tensorrt-cicd]

PR_Github #52254 [ run ] completed with state FAILURE. Commit: 1df8987
/LLM/main/L0_MergeRequest_PR pipeline #41568 completed with status: 'FAILURE'

CI Report

⚠️ Action Required:

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CI Agent Failure Analysis

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[dongfengy]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #52384 [ run ] triggered by Bot. Commit: 339ef49 Link to invocation

[tensorrt-cicd]

PR_Github #52384 [ run ] completed with state SUCCESS. Commit: 339ef49
/LLM/main/L0_MergeRequest_PR pipeline #41680 completed with status: 'FAILURE'

CI Report

⚠️ Action Required:

• Please check the failed tests and fix your PR
• If you cannot view the failures, ask the CI triggerer to share details
• Once fixed, request an NVIDIA team member to trigger CI again

CI Agent Failure Analysis

Link to invocation

[dongfengy]

/bot run --disable-fail-fast

[tensorrt-cicd]

PR_Github #52433 [ run ] triggered by Bot. Commit: 339ef49 Link to invocation