Fix gpt oss weight loading with EP + bf16 #28765
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Signed-off-by: ashors1 <ashors@nvidia.com>
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This pull request correctly identifies and fixes a bug in the _load_weights_other method within the GptOssModel class. The parameters ep_rank_start and ep_rank_end were swapped in the function signature, leading to incorrect weight slicing when using expert parallelism. The change aligns the signature with its call site and makes it consistent with the _load_weights_mxfp4 method, resolving the indexing issue. The fix is accurate and well-contained.
jikunshang
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Nov 15, 2025
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nice catch! thanks for fixing.
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Signed-off-by: ashors1 <ashors@nvidia.com> Signed-off-by: Bram Wasti <bwasti@meta.com>
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Purpose
The signature for
_load_weights_otheris incorrect. The start and end indices are flipped, which casues an indexing issue when attempting to extract the weights on the current EP rank. This fixes the signature to be consistent with_load_weights_mxfp4.Test Plan
Test Result
Running
_load_weights_otherwith EP now works as expected.Essential Elements of an Effective PR Description Checklist
supported_models.mdandexamplesfor a new model.