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See #145101 for details. Pull Request resolved: https://github.com/pytorch/pytorch/pull/145164 Approved by: https://github.com/bobrenjc93
33 lines
1.0 KiB
Python
33 lines
1.0 KiB
Python
from collections.abc import Sequence
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import torch
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from torch.distributed._shard.metadata import ShardMetadata
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DEPRECATE_MSG = "Please use DTensor instead and we are deprecating ShardedTensor."
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def narrow_tensor_by_index(
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tensor: torch.Tensor,
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offsets: Sequence[int],
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sizes: Sequence[int],
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) -> torch.Tensor:
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"""
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Narrow the tensor according to ``offsets`` and ``sizes``.
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"""
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narrowed_tensor = tensor
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for idx, (offset, size) in enumerate(zip(offsets, sizes)):
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if size < tensor.size(idx):
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# Reshape to get shard for this rank and we don't want autograd
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# recording here for the narrow op and 'local_shard' should be a
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# leaf variable in the autograd graph.
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narrowed_tensor = narrowed_tensor.narrow(idx, offset, size)
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return narrowed_tensor
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def narrow_tensor(tensor: torch.Tensor, metadata: ShardMetadata) -> torch.Tensor:
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"""
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Narrow the tensor according to the metadata
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"""
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return narrow_tensor_by_index(tensor, metadata.shard_offsets, metadata.shard_sizes)
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