mindspore.build_train_network

mindspore.build_train_network(network, optimizer, loss_fn=None, level='O0', boost_level='O0', **kwargs)[source]

Build the mixed precision training cell automatically.

Parameters

  • network (Cell) – Definition of the network.

  • loss_fn (Union[None, Cell]) – Definition of the loss_fn. If None, the network should have the loss inside. Default: None.

  • optimizer (Optimizer) – Optimizer to update the Parameter.

  • level (str) –

    Supports [“O0”, “O2”, “O3”, “auto”]. Default: “O0”.

    • O0: Do not change.

    • O2: Cast network to float16, keep batchnorm and loss_fn (if set) run in float32, using dynamic loss scale.

    • O3: Cast network to float16, with additional property keep_batchnorm_fp32=False .

    • auto: Set to level to recommended level in different devices. Set level to O2 on GPU, Set level to O3 Ascend. The recommended level is chosen by the export experience, cannot always general. User should specify the level for special network.

    O2 is recommended on GPU, O3 is recommended on Ascend. Property of keep_batchnorm_fp32, cast_model_type and loss_scale_manager determined by level setting may be overwritten by settings in kwargs.

  • boost_level (str) –

    Option for argument level in mindspore.boost , level for boost mode training. Supports [“O0”, “O1”, “O2”]. Default: “O0”.

    • O0: Do not change.

    • O1: Enable the boost mode, the performance is improved by about 20%, and the accuracy is the same as the original accuracy.

    • O2: Enable the boost mode, the performance is improved by about 30%, and the accuracy is reduced by less than 3%.

    If O1 or O2 mode is set, the boost related library will take effect automatically.

  • cast_model_type (mindspore.dtype) – Supports mstype.float16 or mstype.float32 . If set, the network will be casted to cast_model_type ( mstype.float16 or mstype.float32 ), but not to be casted to the type determined by level setting.

  • keep_batchnorm_fp32 (bool) – Keep Batchnorm run in float32 when the network is set to cast to float16 . If set, the level setting will take no effect on this property.

  • loss_scale_manager (Union[None, LossScaleManager]) – If None, not scale the loss, otherwise scale the loss by LossScaleManager . If set, the level setting will take no effect on this property.

Raises

  • ValueError – Auto mixed precision only supported on device GPU and Ascend. If device is CPU, a ValueError exception will be raised.

  • ValueError – If device is CPU, property loss_scale_manager only can be set as None or FixedLossScaleManager (with property drop_overflow_update=False ), or a ValueError exception will be raised.