[https://nvbugs/5468897][fix] fix invalid expression for disabling pa…

[nv-guomingz]

…rallel loading

Summary by CodeRabbit

• Chores
  • Updated default behavior for model weight loading: when the relevant environment variable is unset, loading now runs in non-parallel mode by default.
  • This may change load-time characteristics (e.g., speed and resource usage) compared to prior versions.
  • Users who prefer parallel loading can explicitly enable it by setting the corresponding environment variable to a truthy value (e.g., “true”, “1”, “yes”).

Description

Test Coverage

PR Checklist

Please review the following before submitting your PR:

• PR description clearly explains what and why. If using CodeRabbit's summary, please make sure it makes sense.

• PR Follows TRT-LLM CODING GUIDELINES to the best of your knowledge.

• Test cases are provided for new code paths (see test instructions)

• Any new dependencies have been scanned for license and vulnerabilities

• CODEOWNERS updated if ownership changes

• Documentation updated as needed

• The reviewers assigned automatically/manually are appropriate for the PR.

• Please check this after reviewing the above items as appropriate for this PR.

GitHub Bot Help

/bot [-h] ['run', 'kill', 'skip', 'reuse-pipeline'] ...

Provide a user friendly way for developers to interact with a Jenkins server.

Run /bot [-h|--help] to print this help message.

See details below for each supported subcommand.

run [--reuse-test (optional)pipeline-id --disable-fail-fast --skip-test --stage-list "A10-PyTorch-1, xxx" --gpu-type "A30, H100_PCIe" --test-backend "pytorch, cpp" --add-multi-gpu-test --only-multi-gpu-test --disable-multi-gpu-test --post-merge --extra-stage "H100_PCIe-TensorRT-Post-Merge-1, xxx" --detailed-log --debug(experimental)]

Launch build/test pipelines. All previously running jobs will be killed.

--reuse-test (optional)pipeline-id (OPTIONAL) : Allow the new pipeline to reuse build artifacts and skip successful test stages from a specified pipeline or the last pipeline if no pipeline-id is indicated. If the Git commit ID has changed, this option will be always ignored. The DEFAULT behavior of the bot is to reuse build artifacts and successful test results from the last pipeline.

--disable-reuse-test (OPTIONAL) : Explicitly prevent the pipeline from reusing build artifacts and skipping successful test stages from a previous pipeline. Ensure that all builds and tests are run regardless of previous successes.

--disable-fail-fast (OPTIONAL) : Disable fail fast on build/tests/infra failures.

--skip-test (OPTIONAL) : Skip all test stages, but still run build stages, package stages and sanity check stages. Note: Does NOT update GitHub check status.

--stage-list "A10-PyTorch-1, xxx" (OPTIONAL) : Only run the specified test stages. Examples: "A10-PyTorch-1, xxx". Note: Does NOT update GitHub check status.

--gpu-type "A30, H100_PCIe" (OPTIONAL) : Only run the test stages on the specified GPU types. Examples: "A30, H100_PCIe". Note: Does NOT update GitHub check status.

--test-backend "pytorch, cpp" (OPTIONAL) : Skip test stages which don't match the specified backends. Only support [pytorch, cpp, tensorrt, triton]. Examples: "pytorch, cpp" (does not run test stages with tensorrt or triton backend). Note: Does NOT update GitHub pipeline status.

--only-multi-gpu-test (OPTIONAL) : Only run the multi-GPU tests. Note: Does NOT update GitHub check status.

--disable-multi-gpu-test (OPTIONAL) : Disable the multi-GPU tests. Note: Does NOT update GitHub check status.

--add-multi-gpu-test (OPTIONAL) : Force run the multi-GPU tests in addition to running L0 pre-merge pipeline.

--post-merge (OPTIONAL) : Run the L0 post-merge pipeline instead of the ordinary L0 pre-merge pipeline.

--extra-stage "H100_PCIe-TensorRT-Post-Merge-1, xxx" (OPTIONAL) : Run the ordinary L0 pre-merge pipeline and specified test stages. Examples: --extra-stage "H100_PCIe-TensorRT-Post-Merge-1, xxx".

--detailed-log (OPTIONAL) : Enable flushing out all logs to the Jenkins console. This will significantly increase the log volume and may slow down the job.

--debug (OPTIONAL) : Experimental feature. Enable access to the CI container for debugging purpose. Note: Specify exactly one stage in the stage-list parameter to access the appropriate container environment. Note: Does NOT update GitHub check status.

For guidance on mapping tests to stage names, see docs/source/reference/ci-overview.md
and the scripts/test_to_stage_mapping.py helper.

kill

kill

Kill all running builds associated with pull request.

skip

skip --comment COMMENT

Skip testing for latest commit on pull request. --comment "Reason for skipping build/test" is required. IMPORTANT NOTE: This is dangerous since lack of user care and validation can cause top of tree to break.

reuse-pipeline

reuse-pipeline

Reuse a previous pipeline to validate current commit. This action will also kill all currently running builds associated with the pull request. IMPORTANT NOTE: This is dangerous since lack of user care and validation can cause top of tree to break.

[coderabbitai]

📝 Walkthrough

Walkthrough

Changed default handling of the TRT_LLM_DISABLE_LOAD_WEIGHTS_IN_PARALLEL environment variable in two weight-loading functions, switching the default-from-missing behavior to "True" (string). This alters the branch selection when the variable is unset, without modifying public APIs.

Changes

Cohort / File(s)	Summary
Env var default for weight loading tensorrt_llm/_torch/models/modeling_utils.py	Updated os.environ.get defaults in _load_weights_impl (True → "True") and _load_weights_impl_v2 (False → "True"); affects membership check against ["True","true","1","yes","y"], changing default path to the non-parallel loading branch when env var is unset.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  actor Caller
  participant Utils as modeling_utils.py
  Note over Utils: Functions: _load_weights_impl / _load_weights_impl_v2

  Caller->>Utils: load_weights(...)
  Utils->>Utils: read env TRT_LLM_DISABLE_LOAD_WEIGHTS_IN_PARALLEL (default "True")
  alt Env is in ["True","true","1","yes","y"] (or unset → "True")
    Note over Utils: New default selects disabled parallel path
    Utils->>Utils: load weights sequentially / non-parallel
  else Env not in list (e.g., "False")
    Utils->>Utils: load weights in parallel
  end
  Utils-->>Caller: return

Loading

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Pre-merge checks and finishing touches

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Description Check	⚠️ Warning	The PR description is essentially the repository template and a short fragment ("…rallel loading") and does not explain the issue, the implemented fix, or test coverage. Required template sections such as Description and Test Coverage are empty and contain no specific implementation details, rationale, or test instructions. The raw_summary shows a behavioral change (changing os.environ.get defaults that affect parallel weight-loading paths), but the description does not document this impact, migration considerations, or tests. Because the description lacks the required content and concrete test information, the check fails.	Please replace the template placeholders with a concise Description that explains the bug, the specific code change (mention modeling_utils.py and the env var default-value changes), and the behavioral impact on parallel weight loading. Add a Test Coverage section listing tests that verify behavior when the environment variable is unset and when set to accepted truthy/falsy values, and include any CI stages or manual test steps. Confirm backward compatibility and whether documentation or a changelog entry is required, include the NVBugs ID in the header, and update the PR checklist as appropriate. After these updates reviewers can re-run checks and continue review.
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Title Check	✅ Passed	The PR title follows the repository template by including the NVBugs ID and the [fix] type and concisely states the primary change (fix invalid expression for disabling parallel loading). The changes in modeling_utils.py modify the environment-variable defaults that control parallel weight loading, which directly matches the title's scope. The title is clear for reviewers, though the displayed string is truncated with an ellipsis; consider ensuring the full phrase "parallel loading" is visible.

✨ Finishing touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

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

[nv-guomingz]

/bot run

[coderabbitai]

Actionable comments posted: 0

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

tensorrt_llm/_torch/models/modeling_utils.py (1)

901-903: Bug: v2 path still uses boolean default; type/behavior inconsistent with _load_weights_impl.

With False (bool) as the default, unset env leads to parallel loading (membership fails) and diverges from the v1 path. Align to the same string default to actually disable parallel loading by default.

Apply this diff:

-    if os.environ.get("TRT_LLM_DISABLE_LOAD_WEIGHTS_IN_PARALLEL",
-                      False) in ["True", "true", "1", "yes", "y"]:
+    if os.environ.get("TRT_LLM_DISABLE_LOAD_WEIGHTS_IN_PARALLEL",
+                      "True") in ["True", "true", "1", "yes", "y"]:

🧹 Nitpick comments (1)

tensorrt_llm/_torch/models/modeling_utils.py (1)

833-835: Optional: centralize env-flag parsing to prevent future drift.

A tiny helper avoids duplication and mismatches across call sites.

Add once (top-level):

def _env_flag(name: str, default: bool) -> bool:
    return str(os.getenv(name, str(default))).lower() in {"true", "1", "yes", "y", "on"}

Then replace both conditionals with:

if _env_flag("TRT_LLM_DISABLE_LOAD_WEIGHTS_IN_PARALLEL", True):
    ...

Also applies to: 901-903

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 64f7cca and 5526ffa.

📒 Files selected for processing (1)

• tensorrt_llm/_torch/models/modeling_utils.py (1 hunks)

🧰 Additional context used

📓 Path-based instructions (3)

**/*.{h,hpp,hh,hxx,cpp,cxx,cc,cu,cuh,py}

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

Use only spaces, no tabs; indent with 4 spaces.

Files:

• tensorrt_llm/_torch/models/modeling_utils.py

**/*.py

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

**/*.py: Python code must target Python 3.8+.
Indent Python code with 4 spaces; do not use tabs.
Maintain module namespace when importing; prefer 'from package.subpackage import foo' then 'foo.SomeClass()' instead of importing the class directly.
Python filenames should be snake_case (e.g., some_file.py).
Python classes use PascalCase names.
Functions and methods use snake_case names.
Local variables use snake_case; prefix 'k' for variables that start with a number (e.g., k_99th_percentile).
Global variables use upper SNAKE_CASE prefixed with 'G' (e.g., G_MY_GLOBAL).
Constants use upper SNAKE_CASE (e.g., MY_CONSTANT).
Avoid shadowing variables from an outer scope.
Initialize all externally visible members of a class in the constructor.
Prefer docstrings for interfaces that may be used outside a file; comments for in-function or file-local interfaces.
Use Google-style docstrings for classes and functions (Sphinx-parsable).
Document attributes and variables inline so they render under the class/function docstring.
Avoid reflection when a simpler, explicit approach suffices (e.g., avoid dict(**locals()) patterns).
In try/except, catch the most specific exceptions possible.
For duck-typing try/except, keep the try body minimal and use else for the main logic.

Files:

• tensorrt_llm/_torch/models/modeling_utils.py

**/*.{cpp,cxx,cc,h,hpp,hh,hxx,cu,cuh,py}

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

Prepend the NVIDIA Apache-2.0 copyright header with current year to the top of all source files (e.g., .cpp, .h, .cu, .py).

Files:

• tensorrt_llm/_torch/models/modeling_utils.py

🧠 Learnings (1)

📚 Learning: 2025-08-14T15:38:01.771Z

Learnt from: MatthiasKohl
PR: NVIDIA/TensorRT-LLM#6904
File: cpp/tensorrt_llm/pybind/thop/bindings.cpp:55-57
Timestamp: 2025-08-14T15:38:01.771Z
Learning: In TensorRT-LLM Python bindings, tensor parameter collections like mla_tensor_params and spec_decoding_tensor_params are kept as required parameters without defaults to maintain API consistency, even when it might affect backward compatibility.

Applied to files:

• tensorrt_llm/_torch/models/modeling_utils.py

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Pre-commit Check

🔇 Additional comments (1)

tensorrt_llm/_torch/models/modeling_utils.py (1)

833-835: Fix is correct: use string default so membership test works.

Stringifying the default to "True" ensures the truthy check against ["True","true","1","yes","y"] triggers when the env var is unset. Please confirm that disabling parallel loading by default is intended for release/1.0.

[tensorrt-cicd]

PR_Github #18760 [ run ] triggered by Bot

[tensorrt-cicd]

PR_Github #18760 [ run ] completed with state SUCCESS
/LLM/release-1.0/L0_MergeRequest_PR pipeline #395 completed with status: 'SUCCESS'