Support CP and CP + DP in dispatch mode dataloader #3863
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Signed-off-by: Mehant Kammakomati <[email protected]>
Signed-off-by: Mehant Kammakomati <[email protected]>
SunMarc
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Dec 1, 2025
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Thanks for updating this ! Left a comment. Just a quick question, are you always using DataLoaderDispatcher ? do DataLoaderShard requires some modifications also to work also ? Also, can you add some tests to check that DataLoaderDispatcher is behaving correctly when cp is used ?
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| if "tp" in self.torch_device_mesh.mesh_dim_names: | ||
| raise ValueError("TP + CP combination is not yet supported in dispatch mode.") |
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we can't make fsdp + tp work also, so it's fine to not put that since we require cp to be used with fsdp
| # multiplied by number of cp groups (dp degree). | ||
| if self.submesh_cp: | ||
| cp_degree = self.submesh_cp.size() | ||
| dp_degree = self.torch_device_mesh.size() // cp_degree |
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self.submesh_dp.size() * self.submesh_fsdp.size() would be better no ?
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| for i in range(dp_degree): | ||
| portion = slice( | ||
| i * number_of_samples_per_dp_group, (i + 1) * number_of_samples_per_dp_group | ||
| ) | ||
| dp_batch = self.slice_fn(batch, portion) | ||
| for _ in range(cp_degree): | ||
| batches.append(dp_batch) | ||
| batch = concatenate(batches, dim=0) |
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explain a bit mroe what's happening here
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What does this PR do?
Extends dispatch mode dataloader for CP and CP + DP usecases.
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