# Copyright 2022 Huawei Technologies Co., Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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# ============================================================================
"""Group Loss Scale Manager"""
from __future__ import absolute_import
from __future__ import division
from mindspore.nn.cell import Cell
import mindspore.common.dtype as mstype
from mindspore.ops import operations as P
from mindspore.common.tensor import Tensor
from mindspore.common.parameter import Parameter, ParameterTuple
__all__ = ["GroupLossScaleManager"]
[文档]class GroupLossScaleManager(Cell):
r"""
Enhanced hybrid precision algorithm supports multi-layer application of different loss scales and
dynamic updating of loss scales.
Args:
init_loss_scale (Number): The initialized loss scale value.
loss_scale_groups (List): The loss scale groups, which are divided from the param list.
Inputs:
- **x** (Tensor) - The output of last operator.
- **layer1** (Int) - Current network layer value.
- **layer2** (Int) - Last network layer value.
Outputs:
- **out** (Tensor) - A tensor with a group of loss scale tags that marks
the loss scale group number of the current tensor.
Supported Platforms:
``Ascend``
Examples:
>>> import mindspore as ms
>>> from mindspore import boost, nn
>>>
>>> class Net(nn.Cell):
... def __init__(self, enhanced_amp, num_class=10, num_channel=1):
... super(Net, self).__init__()
... self.conv1 = nn.Conv2d(num_channel, 6, 5, pad_mode='valid')
... self.conv2 = nn.Conv2d(6, 16, 5, pad_mode='valid')
... self.fc1 = nn.Dense(16*5*5, 120, weight_init='ones')
... self.fc2 = nn.Dense(120, 84, weight_init='ones')
... self.fc3 = nn.Dense(84, num_class, weight_init='ones')
... self.relu = nn.ReLU()
... self.max_pool2d = nn.MaxPool2d(kernel_size=2, stride=2)
... self.flatten = nn.Flatten()
... self.enhanced_amp = enhanced_amp
...
... def construct(self, x):
... x = self.enhanced_amp(x, 0, 1)
... x = self.max_pool2d(self.relu(self.conv1(x)))
... x = self.max_pool2d(self.relu(self.conv2(x)))
... x = self.flatten(x)
... x = self.enhanced_amp(x, 1, 2)
... x = self.relu(self.fc1(x))
... x = self.relu(self.fc2(x))
... x = self.fc3(x)
... x = self.enhanced_amp(x, 2, 3)
... return x
>>>
>>> loss_scale_manager = boost.GroupLossScaleManager(4096, [])
>>> net = Net(loss_scale_manager)
>>> param_group1 = []
>>> param_group2 = []
>>> for param in net.trainable_params():
... if 'conv' in param.name:
... param_group1.append(param)
... else:
... param_group2.append(param)
>>> loss_scale_manager.loss_scale_groups = [param_group1, param_group2]
>>> loss = nn.SoftmaxCrossEntropyWithLogits()
>>> optim = nn.Momentum(params=net.trainable_params(), learning_rate=0.1, momentum=0.9)
>>> boost_config_dict = {"boost": {"mode": "manual", "less_bn": False, "grad_freeze": False, "adasum": False,
... "grad_accumulation": False, "dim_reduce": False, "loss_scale_group": True}}
>>> model = ms.train.Model(net, loss_fn=loss, optimizer=optim, metrics=None,
... loss_scale_manager=loss_scale_manager,
... boost_level="O1", boost_config_dict=boost_config_dict)
>>> # Create the dataset taking MNIST as an example. Refer to
>>> # https://gitee.com/mindspore/docs/blob/r2.3.0/docs/mindspore/code/mnist.py
>>> dataset = create_dataset()
>>> model.train(2, dataset)
"""
def __init__(self, init_loss_scale, loss_scale_groups):
super(GroupLossScaleManager, self).__init__()
self._loss_scale = init_loss_scale
self.loss_scale_groups = loss_scale_groups
self.loss_scale_number = 0
self.layer_loss_scale = None
self.dynamic_loss_scale = None
[文档] def set_loss_scale_status(self, loss_scale_number, init_loss_scale):
"""
Generate dynamic loss scale tuple and set overflow status list.
Args:
loss_scale_number (int): The number of loss scale.
init_loss_scale (float): The initialized loss scale.
"""
self.loss_scale_number = loss_scale_number
inner_list = [P._DynamicLossScale(layer=x) for x in range(loss_scale_number + 1)] # pylint: disable=W0212
self.layer_loss_scale = tuple(inner_list)
self.dynamic_loss_scale = ParameterTuple(Parameter(Tensor(1, mstype.float32),
name='layer_loss_scale_{}'.format(x), requires_grad=False)
for x in range(loss_scale_number + 2))
if isinstance(init_loss_scale, list):
for i, value in enumerate(init_loss_scale):
self.dynamic_loss_scale[i + 1].set_data(value)
else:
for i in range(self.loss_scale_number):
self.dynamic_loss_scale[i + 1].set_data(init_loss_scale)
[文档] def update_loss_scale_status(self, layer, update_ratio):
"""
Update dynamic loss scale.
Args:
layer (int): Current layer.
update_ratio (float): The ratio of loss scale update.
Outputs:
float, new loss scale.
"""
layer = layer + 1
new_loss_scale = self.dynamic_loss_scale[layer] * update_ratio
P.Assign()(self.dynamic_loss_scale[layer], new_loss_scale)
return new_loss_scale
def construct(self, x, layer1, layer2):
x = self.layer_loss_scale[layer1](x, self.dynamic_loss_scale[layer1] / self.dynamic_loss_scale[layer2])
return x
[文档] def get_loss_scale(self):
"""
Get loss scale value.
Returns:
bool, `loss_scale` value.
"""
return self._loss_scale
[文档] def get_update_cell(self):
"""
Returns the instance of :class:`mindspore.boost.GroupLossScaleManager`.
Returns:
:class:`mindspore.boost.GroupLossScaleManager`.
"""
return self