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fab8085111
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/14929 Reviewed By: weiyangfb Differential Revision: D13394498 Pulled By: soumith fbshipit-source-id: 948c6118abdf6c1e1a8a17709333954cafb2345e
36 lines
1.3 KiB
Python
36 lines
1.3 KiB
Python
import torch
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import torch._six
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def _get_device_index(device, optional=False):
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r"""Gets the device index from :attr:`device`, which can be a torch.device
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object, a Python integer, or ``None``.
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If :attr:`device` is a torch.device object, returns the device index if it
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is a CUDA device. Note that for CUDA device without sepecified index, i.e.,
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``torch.devie('cuda')``, this will return the current default CUDA device if
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:attr:`optional` is ``True``.
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If :attr:`device` is a Python interger, it is returned as is.
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If :attr:`device` is ``None``, this will return the current default CUDA
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device if :attr:`optional` is ``True``.
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"""
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if isinstance(device, torch._six.string_classes):
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device = torch.device(device)
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if isinstance(device, torch.device):
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dev_type = device.type
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if device.type != 'cuda':
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raise ValueError('Expected a cuda device, but got: {}'.format(device))
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device_idx = device.index
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else:
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device_idx = device
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if device_idx is None:
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if optional:
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# default cuda device index
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return torch.cuda.current_device()
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else:
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raise ValueError('Expected a cuda device with sepecified index or '
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'an integer, but got: '.format(device))
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return device_idx
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