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Ensure that inference dummy_forward does not try to match on a cudagraph when running eager#3815

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tdene merged 8 commits intoNVIDIA:mainfrom
mathemakitten:helenn-fix-3789
Mar 13, 2026
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Ensure that inference dummy_forward does not try to match on a cudagraph when running eager#3815
tdene merged 8 commits intoNVIDIA:mainfrom
mathemakitten:helenn-fix-3789

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What does this PR do ?

Fix for #3789.

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@mathemakitten mathemakitten requested review from a team as code owners March 12, 2026 03:08
@svcnvidia-nemo-ci svcnvidia-nemo-ci marked this pull request as draft March 12, 2026 03:08
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can we make this @torch inference mode?

# cudagraph check (which gates on using_cuda_graph_this_step()) instead of
# the training-mode check (which unconditionally replays captured graphs
# when inference_context is not in kwargs).
return self.model(
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I'm a bit scared that this will lead to segfaults. If we pass the inference context, we will attempt to write into the kv-cache/mamba-cache. But we are not setting up the required pointers properly.

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Removed this in favour of gating on inference_mode instead

@mathemakitten mathemakitten marked this pull request as ready for review March 12, 2026 17:31
@svcnvidia-nemo-ci svcnvidia-nemo-ci added the Final Review PR is in the "final review" stage label Mar 12, 2026
@svcnvidia-nemo-ci svcnvidia-nemo-ci added Approved All necessary approvals have been made and removed Final Review PR is in the "final review" stage labels Mar 12, 2026
@tdene tdene added this pull request to the merge queue Mar 13, 2026
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🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/23060422351

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🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/23062146973

Merged via the queue into NVIDIA:main with commit 90fee1f Mar 13, 2026
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7 participants