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fix: Don't call broadcast on dtensor #627

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Merged
merged 1 commit into from
Jul 9, 2025
Merged

fix: Don't call broadcast on dtensor #627

merged 1 commit into from
Jul 9, 2025

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parthchadha
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(enabling sp converts internal buffers to dtensor and broadcast was failing)

What does this PR do ?

Fixes below issue seen with some models:

(DTensorPolicyWorker pid=343603)   File "/app/ray_venvs/nemo_rl.models.policy.dtensor_policy_worker.DTensorPolicyWorker/lib/python3.12/site-packages/torch/distributed/tensor/_dispatch.py", line 393, in unwrap_to_op_info [repeated 6x across cluster]
(DTensorPolicyWorker pid=343603)     assert compute_mesh is not None, ( [repeated 6x across cluster]
(DTensorPolicyWorker pid=343603)            ^^^^^^^^^^^^^^^^^^^^^^^^ [repeated 6x across cluster]
(DTensorPolicyWorker pid=343603) AssertionError: found no DeviceMesh from dtensor args for c10d.broadcast_.default! [repeated 6x across cluster]

Issues

Closes #621.

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@parthchadha
Don't call broadcast dtensor (enabling sp converts internal buffers t…
5afdb6a 
…o dtensor)

Signed-off-by: Parth Chadha <pchadha@nvidia.com>
@parthchadha parthchadha requested review from SahilJain314 and terrykong and removed request for SahilJain314 July 8, 2025 23:19
terrykong
terrykong approved these changes Jul 8, 2025
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nice!

@terrykong terrykong added this pull request to the merge queue Jul 8, 2025
Merged via the queue into main with commit 3b070a4 Jul 9, 2025
13 of 14 checks passed
@terrykong terrykong deleted the pchadha/fix-qwen-sp-bug branch July 9, 2025 01:27
jialei777 pushed a commit to jialei777/nemo-rl that referenced this pull request Jul 23, 2025
@parthchadha @jialei777
fix: Don't call broadcast on dtensor (NVIDIA-NeMo#627)
adf167c 
Signed-off-by: Parth Chadha <pchadha@nvidia.com>
Signed-off-by: Jialei Chen <jialeic@google.com>
KiddoZhu pushed a commit that referenced this pull request Jul 28, 2025
@parthchadha @KiddoZhu
fix: Don't call broadcast on dtensor (#627)
214712c 
Signed-off-by: Parth Chadha <pchadha@nvidia.com>
FannYYW pushed a commit to xxman-google/NeMo-RL that referenced this pull request Aug 5, 2025
@parthchadha
fix: Don't call broadcast on dtensor (NVIDIA-NeMo#627)
9b9315b 
Signed-off-by: Parth Chadha <pchadha@nvidia.com>
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@terrykong terrykong terrykong approved these changes

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FSDP2+TP2 demo script does not work
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