| # Copyright (c) 2016-present, Facebook, Inc. |
| # |
| # 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, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| ############################################################################## |
| |
| ## @package optimizer |
| # Module caffe2.python.optimizer |
| from __future__ import absolute_import |
| from __future__ import division |
| from __future__ import print_function |
| from __future__ import unicode_literals |
| |
| from collections import namedtuple, defaultdict |
| from past.builtins import basestring |
| |
| import numpy as np |
| |
| from caffe2.python import core, scope, workspace |
| from caffe2.python.modeling import parameter_info |
| from caffe2.proto import caffe2_pb2 |
| |
| |
| _OPTIMIZER_ITERATION_NAME = "optimizer_iteration" |
| _LEARNING_RATE_INJECTION = "lr_injection" |
| |
| AuxOptimizerParams = namedtuple("AuxOptimizerParams", ["local", "shared"]) |
| _optimizer_instance_count = defaultdict(int) |
| |
| |
| class Optimizer(object): |
| def __init__(self): |
| self._aux_params = AuxOptimizerParams(local=[], shared=[]) |
| self._instance_num = _optimizer_instance_count[self.__class__.__name__] |
| _optimizer_instance_count[self.__class__.__name__] += 1 |
| self._lr_multiplier = None |
| |
| ''' |
| Adds optimization operators to the net for given parameter and its gradient |
| Parameter is specified by either 'param' being a ParameterInfo object. |
| In this case param.grad has to be set |
| |
| Or by 'param' being a BlobReference and 'grad' being a BlobReference for its |
| gradient. |
| ''' |
| def __call__(self, net, param_init_net, param, grad=None): |
| if grad is None: |
| assert isinstance(param, parameter_info.ParameterInfo) |
| assert param.grad is not None |
| else: |
| if isinstance(param, basestring): |
| param = core.BlobReference(param) |
| param = parameter_info.ParameterInfo( |
| param_id=None, param=param, grad=grad) |
| |
| self._run(net, param_init_net, param) |
| |
| def _run(self, net, param_init_net, param_info): |
| raise Exception("Not Implemented") |
| |
| def get_cpu_blob_name(self, base_str, node_name=''): |
| classname = self.__class__.__name__ |
| return '%s_%d_%s%s_cpu' % (classname, self._instance_num, base_str, node_name) |
| |
| def get_gpu_blob_name(self, base_str, gpu_id, node_name): |
| classname = self.__class__.__name__ |
| return '%s_%d_%s%s_gpu%d' % ( |
| classname, self._instance_num, base_str, node_name, gpu_id, |
| ) |
| |
| def make_unique_blob_name(self, base_str): |
| """ |
| Returns a blob name that will be unique to the current device |
| and optimizer instance. |
| """ |
| current_scope = scope.CurrentDeviceScope() |
| if current_scope is None: |
| return self.get_cpu_blob_name(base_str) |
| |
| if current_scope.device_type == caffe2_pb2.CUDA: |
| return self.get_gpu_blob_name( |
| base_str, current_scope.cuda_gpu_id, current_scope.node_name |
| ) |
| else: |
| return self.get_cpu_blob_name(base_str, current_scope.node_name) |
| |
| def build_lr(self, net, param_init_net, base_learning_rate, |
| learning_rate_blob=None, policy="fixed", |
| iter_val=0, **kwargs): |
| if learning_rate_blob is None: |
| learning_rate_blob = self.make_unique_blob_name('lr') |
| |
| # Each node needs its own iteration counter |
| current_scope = scope.CurrentDeviceScope() |
| node_name = current_scope.node_name if current_scope else '' |
| optimization_iter_blob = _OPTIMIZER_ITERATION_NAME + node_name |
| if not param_init_net.BlobIsDefined(optimization_iter_blob): |
| # Add training operators. |
| with core.DeviceScope(core.DeviceOption(caffe2_pb2.CPU)): |
| iteration = param_init_net.ConstantFill( |
| [], optimization_iter_blob, shape=[1], |
| value=iter_val, |
| dtype=core.DataType.INT64) |
| iter_mutex = param_init_net.CreateMutex( |
| [], ["iteration_mutex" + node_name] |
| ) |
| net.AtomicIter([iter_mutex, iteration], [iteration]) |
| else: |
| iteration = param_init_net.GetBlobRef(optimization_iter_blob) |
| |
| if not net.BlobIsDefined(learning_rate_blob): |
| # There is one interesting thing here: since we are minimizing, we are |
| # doing "descent" so the learning rate is set to be negative. |
| lr = net.LearningRate( |
| [iteration], |
| learning_rate_blob, |
| base_lr=-base_learning_rate, |
| policy=policy, |
| **kwargs |
| ) |
| else: |
| lr = net.GetBlobRef(learning_rate_blob) |
| |
| if self._lr_multiplier is not None: |
| lr_multiplier = net.CopyFromCPUInput( |
| self._lr_multiplier, self.make_unique_blob_name('lr_multiplier') |
| ) |
| scaled_lr = net.Mul( |
| [lr, lr_multiplier], |
| self.make_unique_blob_name('scaled_lr'), |
| broadcast=1, |
| ) |
| lr = scaled_lr |
| |
| return lr, iteration |
| |
| def add_lr_multiplier(self, lr_multiplier): |
| self._lr_multiplier = lr_multiplier |
| |
| @staticmethod |
| def dedup(net, sparse_dedup_aggregator, grad): |
| assert (isinstance(grad, core.GradientSlice)) |
| if sparse_dedup_aggregator: |
| return net.DeduplicateGradientSlices( |
| grad, aggregator=sparse_dedup_aggregator) |
| else: |
| return grad |
| |
| def get_auxiliary_parameters(self): |
| """Returns a list of auxiliary parameters. |
| |
| Returns: |
| aux_params: A namedtuple, AuxParams. |
| |
| aux_params.local stores a list of blobs. Each blob is a local |
| auxiliary parameter. A local auxiliary parameter is a parameter in |
| parallel to a learning rate parameter. Take adagrad as an example, |
| the local auxiliary parameter is the squared sum parameter, because |
| every learning rate has a squared sum associated with it. |
| |
| aux_params.shared also stores a list of blobs. Each blob is a shared |
| auxiliary parameter. A shared auxiliary parameter is a parameter |
| that is shared across all the learning rate parameters. Take adam as |
| an example, the iteration parameter is a shared parameter, because |
| all the learning rates share the same iteration parameter. |
| """ |
| return self._aux_params |
| |
| # TODO(xlwang): In transfer learning, parameter initialized from pretrained |
| # model might require a different learning rate than otherwise initialized. |
| # To this end, here we implement a python solution where |
| # `base_learning_rate` is scaled by `scale`, by calling |
| # `scale_learning_rate`; Alternatively, we can achieve same effect by |
| # rewriting the LearningRate operator in C++ |
| # Note that it is the responsibility of specific optimizer to decide what |
| # logic should be used for `scale_learning_rate` |
| def scale_learning_rate(self, *args, **kwargs): |
| raise NotImplementedError( |
| "Optimizer Need to Implement `scale_learning_rate` method.") |
| |
| |
| class SgdOptimizer(Optimizer): |
| def __init__(self, base_learning_rate=0.01, policy='fixed', |
| momentum=0.0, nesterov=1, sparse_dedup_aggregator=None, |
| **kwargs): |
| super(SgdOptimizer, self).__init__() |
| self.base_learning_rate = base_learning_rate |
| self.policy = policy |
| self.momentum = momentum |
| self.nesterov = nesterov |
| self.sparse_dedup_aggregator = sparse_dedup_aggregator |
| self.init_kwargs = kwargs |
| |
| def _run(self, net, param_init_net, param_info): |
| param = param_info.blob |
| grad = param_info.grad |
| if self.base_learning_rate == 0: |
| return |
| assert self.base_learning_rate > 0 |
| |
| # We need negative sign for LR when used directly with WeightedSum |
| # below. |
| lr_sign = -1 if self.momentum else 1 |
| lr, _ = self.build_lr( |
| net, param_init_net, |
| base_learning_rate=self.base_learning_rate * lr_sign, |
| policy=self.policy, |
| **(self.init_kwargs) |
| ) |
| |
| dev = scope.CurrentDeviceScope() |
| if dev is None: |
| dev = core.DeviceOption(caffe2_pb2.CPU) |
| |
| # Each GPU/CPU must have its own ONE blob, thus modify the name |
| # to include device information. |
| ONE = param_init_net.ConstantFill( |
| [], |
| "ONE_{}_{}{}".format(dev.device_type, dev.cuda_gpu_id, dev.node_name), |
| shape=[1], |
| value=1.0 |
| ) |
| |
| self._aux_params.shared.append(ONE) |
| |
| if self.momentum > 0: |
| momentum_data = param_init_net.ConstantFill( |
| param, str(param) + "_momentum", value=0.) |
| self._aux_params.local.append(momentum_data) |
| |
| if isinstance(grad, core.GradientSlice): |
| assert self.momentum == 0., "Doesn't support momentum for sparse" |
| grad = self.dedup(net, self.sparse_dedup_aggregator, grad) |
| net.ScatterWeightedSum( |
| [param, ONE, grad.indices, grad.values, lr], |
| param |
| ) |
| else: |
| if self.momentum > 0.: |
| net.MomentumSGDUpdate( |
| [grad, momentum_data, lr, param], |
| [grad, momentum_data, param], |
| momentum=self.momentum, |
| nesterov=self.nesterov) |
| else: |
| coeff = lr |
| |
| net.WeightedSum( |
| [param, ONE, grad, coeff], |
| param |
| ) |
| |
| def scale_learning_rate(self, scale): |
| self.base_learning_rate *= scale |
| return |
| |
| |
| class MultiPrecisionSgdOptimizer(SgdOptimizer): |
| def __init__(self, base_learning_rate=0.1, momentum=0.0, |
| policy="fixed", nesterov=1, sparse_dedup_aggregator=None, |
| **kwargs): |
| super(SgdOptimizer, self).__init__() |
| self.base_learning_rate = base_learning_rate |
| self.momentum = momentum |
| self.policy = policy |
| self.nesterov = nesterov |
| self.sparse_dedup_aggregator = sparse_dedup_aggregator |
| self.init_kwargs = kwargs |
| |
| def _run(self, net, param_init_net, param_info): |
| param = param_info.blob |
| param_fp32 = param_info.blob_copy[core.DataType.FLOAT] \ |
| if param_info.blob_copy is not None else None |
| |
| # If we have a straight fp32 parameter, run the base class |
| if param_fp32 is None: |
| return SgdOptimizer._run(self, net, param_init_net, param_info) |
| |
| grad = param_info.grad |
| if self.base_learning_rate == 0: |
| return |
| assert self.base_learning_rate > 0 |
| |
| lr, _ = self.build_lr( |
| net, param_init_net, |
| base_learning_rate=-self.base_learning_rate, |
| policy=self.policy, |
| **(self.init_kwargs) |
| ) |
| |
| momentum_data = param_init_net.ConstantFill( |
| param_fp32, str(param) + "_momentum", value=0.) |
| self._aux_params.local.append(momentum_data) |
| |
| assert not isinstance(grad, core.GradientSlice), \ |
| "Doesn't support sparse gradients" |
| |
| # Copy gradient to fp32 |
| grad_fp32 = net.HalfToFloat(grad, grad + "_fp32") |
| |
| # update (fused) in fp32 |
| net.MomentumSGDUpdate( |
| [grad_fp32, momentum_data, lr, param_fp32], |
| [grad_fp32, momentum_data, param_fp32], |
| momentum=self.momentum, |
| nesterov=self.nesterov) |
| |
| # Copy updated param back to fp16 |
| net.FloatToHalf(param_fp32, param) |
| |
| |
| class WeightDecayBuilder(Optimizer): |
| def __init__(self, weight_decay): |
| self.weight_decay = weight_decay |
| |
| def _run(self, net, param_init_net, param_info): |
| dev = scope.CurrentDeviceScope() |
| if dev is None: |
| dev = core.DeviceOption(caffe2_pb2.CPU) |
| |
| ONE = param_init_net.ConstantFill( |
| [], |
| "ONE_{}_{}".format(dev.device_type, dev.cuda_gpu_id), |
| shape=[1], |
| value=1.0 |
| ) |
| WD = param_init_net.ConstantFill( |
| [], "wd_{}_{}".format(dev.device_type, dev.cuda_gpu_id), |
| shape=[1], value=self.weight_decay |
| ) |
| |
| if isinstance(param_info.grad, core.GradientSlice): |
| assert "Weight decay does not yet support sparse gradients" |
| else: |
| net.WeightedSum( |
| [param_info.grad, ONE, param_info.blob, WD], |
| param_info.grad, |
| ) |
| |
| |
| class AdagradOptimizer(Optimizer): |
| def __init__(self, alpha=0.01, epsilon=1e-4, decay=1, policy="fixed", |
| sparse_dedup_aggregator=None, rowWise=False, |
| engine='', **kwargs): |
| super(AdagradOptimizer, self).__init__() |
| self.alpha = alpha |
| self.epsilon = epsilon |
| self.decay = decay |
| self.policy = policy |
| self.sparse_dedup_aggregator = sparse_dedup_aggregator |
| self.engine = engine |
| self.init_kwargs = kwargs |
| self.rowWise = rowWise |
| |
| def _run(self, net, param_init_net, param_info): |
| param = param_info.blob |
| grad = param_info.grad |
| |
| if self.alpha <= 0: |
| return |
| |
| lr, _ = self.build_lr( |
| net, param_init_net, |
| base_learning_rate=self.alpha, |
| policy=self.policy, |
| **(self.init_kwargs) |
| ) |
| |
| if self.rowWise: |
| shape = param_init_net.Shape(param, str(param) + "_shape") |
| slice_starts = np.array([0]).astype(np.int32) |
| slice_ends = np.array([1]).astype(np.int32) |
| slice_starts = param_init_net.GivenTensorIntFill( |
| [], shape=[1], values=slice_starts |
| ) |
| slice_ends = param_init_net.GivenTensorIntFill( |
| [], shape=[1], values=slice_ends |
| ) |
| num_rows = param_init_net.Slice( |
| [shape, slice_starts, slice_ends], |
| str(shape) + "_numrows" |
| ) |
| param_squared_sum = param_init_net.ConstantFill( |
| num_rows, |
| str(param) + "_avg_squared_sum", |
| input_as_shape=1, |
| value=0.0 |
| ) |
| else: |
| param_squared_sum = param_init_net.ConstantFill( |
| [param], |
| str(param) + "_squared_sum", |
| value=0.0 |
| ) |
| |
| self._aux_params.local.append(param_squared_sum) |
| |
| if self.rowWise: |
| assert isinstance(grad, core.GradientSlice),\ |
| 'If SparseAdagrad with rowWise=True, gradient must be gradientslice' |
| if isinstance(grad, core.GradientSlice): |
| assert self.decay == 1.,\ |
| 'Decay is not implemented for SparseAdagrad and must be set to 1' |
| grad = self.dedup(net, self.sparse_dedup_aggregator, grad) |
| if self.rowWise: |
| op = 'RowWiseSparseAdagrad' |
| else: |
| op = 'SparseAdagrad' |
| net.__getattr__(op)( |
| [param, param_squared_sum, grad.indices, grad.values, lr], |
| [param, param_squared_sum], |
| epsilon=self.epsilon, |
| engine=self.engine |
| ) |
| else: |
| net.Adagrad( |
| [param, param_squared_sum, grad, lr], |
| [param, param_squared_sum], |
| epsilon=self.epsilon, |
| decay=float(self.decay), |
| engine=self.engine |
| ) |
| |
| def scale_learning_rate(self, scale): |
| self.alpha *= scale |
| return |
| |
| |
| class FtrlOptimizer(Optimizer): |
| def __init__(self, alpha=0.01, beta=1e-4, lambda1=0, lambda2=0, |
| sparse_dedup_aggregator=None, engine=''): |
| super(FtrlOptimizer, self).__init__() |
| self.alpha = alpha |
| self.beta = beta |
| self.lambda1 = lambda1 |
| self.lambda2 = lambda2 |
| self.sparse_dedup_aggregator = sparse_dedup_aggregator |
| self.engine = engine |
| |
| def _run(self, net, param_init_net, param_info): |
| param = param_info.blob |
| grad = param_info.grad |
| |
| if self.alpha <= 0: |
| return |
| |
| nz = param_init_net.ConstantFill( |
| [param], |
| str(param) + "_ftrl_nz", |
| extra_shape=[2], |
| value=0.0 |
| ) |
| self._aux_params.local.append(nz) |
| if isinstance(grad, core.GradientSlice): |
| grad = self.dedup(net, self.sparse_dedup_aggregator, grad) |
| net.SparseFtrl( |
| [param, nz, grad.indices, grad.values], |
| [param, nz], |
| engine=self.engine, |
| alpha=self.alpha, |
| beta=self.beta, |
| lambda1=self.lambda1, |
| lambda2=self.lambda2 |
| ) |
| else: |
| net.Ftrl( |
| [param, nz, grad], |
| [param, nz], |
| engine=self.engine, |
| alpha=self.alpha, |
| beta=self.beta, |
| lambda1=self.lambda1, |
| lambda2=self.lambda2 |
| ) |
| |
| def scale_learning_rate(self, scale): |
| self.alpha *= scale |
| return |
| |
| |
| class AdamOptimizer(Optimizer): |
| def __init__(self, alpha=0.001, beta1=0.9, beta2=0.999, epsilon=1e-8, |
| policy='fixed', sparse_dedup_aggregator=None, |
| engine='', **kwargs): |
| super(AdamOptimizer, self).__init__() |
| self.alpha = alpha |
| self.beta1 = beta1 |
| self.beta2 = beta2 |
| self.epsilon = epsilon |
| self.policy = policy |
| self.sparse_dedup_aggregator = sparse_dedup_aggregator |
| self.engine = engine |
| self.init_kwargs = kwargs |
| |
| def _run(self, net, param_init_net, param_info): |
| param = param_info.blob |
| grad = param_info.grad |
| |
| if self.alpha <= 0: |
| return |
| |
| lr, iteration = self.build_lr( |
| net, param_init_net, |
| base_learning_rate=self.alpha, |
| policy=self.policy, |
| **(self.init_kwargs) |
| ) |
| |
| m1 = param_init_net.ConstantFill( |
| [param], |
| param + "_first_moment", |
| value=0.0 |
| ) |
| m2 = param_init_net.ConstantFill( |
| [param], |
| param + "_second_moment", |
| value=0.0 |
| ) |
| self._aux_params.shared.append(iteration) |
| self._aux_params.local.append(m1) |
| self._aux_params.local.append(m2) |
| if isinstance(grad, core.GradientSlice): |
| grad = self.dedup(net, self.sparse_dedup_aggregator, grad) |
| net.SparseAdam( |
| [param, m1, m2, grad.indices, grad.values, lr, iteration], |
| [param, m1, m2], |
| beta1=self.beta1, |
| beta2=self.beta2, |
| epsilon=self.epsilon |
| ) |
| |
| else: |
| net.Adam( |
| [param, m1, m2, grad, lr, iteration], |
| [param, m1, m2], |
| beta1=self.beta1, |
| beta2=self.beta2, |
| epsilon=self.epsilon) |
| |
| def scale_learning_rate(self, scale): |
| self.alpha *= scale |
| return |
| |
| |
| class YellowFinOptimizer(Optimizer): |
| """YellowFin: An automatic tuner for momentum SGD |
| |
| See https://arxiv.org/abs/1706.03471 for more details. This implementation |
| has separate learning rate and momentum per each parameter.""" |
| |
| def __init__(self, |
| alpha=0.1, |
| mu=0.0, |
| beta=0.999, |
| curv_win_width=20, |
| zero_debias=True, |
| epsilon=0.1**6, |
| policy='fixed', |
| sparse_dedup_aggregator=None, |
| **kwargs): |
| super(YellowFinOptimizer, self).__init__() |
| self.alpha = alpha |
| self.mu = mu |
| self.beta = beta |
| self.curv_win_width = curv_win_width |
| self.zero_debias = zero_debias |
| self.epsilon = epsilon |
| self.policy = policy |
| self.sparse_dedup_aggregator = sparse_dedup_aggregator |
| self.init_kwargs = kwargs |
| |
| def _run(self, net, param_init_net, param_info): |
| |
| # Note: This is number of persistent scalars in YellowFin optimizer. |
| # It should always be the number of scalars being used. The same |
| # number should be used in class for the operation. |
| SCALARS_MEMORY_SIZE = 5 |
| |
| param = param_info.blob |
| grad = param_info.grad |
| moment = param_init_net.ConstantFill( |
| [param], |
| param + "_moment", |
| value=0.0 |
| ) |
| curv_win = param_init_net.ConstantFill( |
| [], |
| param + "_curv_win", |
| shape=[self.curv_win_width], |
| value=0.0 |
| ) |
| g_avg = param_init_net.ConstantFill( |
| [param], |
| param + "_g_avg", |
| value=0.0 |
| ) |
| g2_avg = param_init_net.ConstantFill( |
| [param], |
| param + "_g2_avg", |
| value=0.0 |
| ) |
| lr_avg = param_init_net.ConstantFill( |
| [], |
| param + "_lr_avg", |
| shape=[1], |
| value=self.alpha |
| ) |
| mu_avg = param_init_net.ConstantFill( |
| [], |
| param + "_mu_avg", |
| shape=[1], |
| value=self.mu |
| ) |
| scalars_memory = param_init_net.ConstantFill( |
| [], |
| param + "_scalars_memory", |
| shape=[SCALARS_MEMORY_SIZE], |
| value=0.0 |
| ) |
| |
| assert self.alpha > 0 |
| assert not isinstance(grad, core.GradientSlice), \ |
| "Doesn't support sparse gradients" |
| |
| if not param_init_net.BlobIsDefined(_OPTIMIZER_ITERATION_NAME): |
| # Add training operators. |
| with core.DeviceScope(core.DeviceOption(caffe2_pb2.CPU)): |
| iteration = param_init_net.ConstantFill( |
| [], |
| _OPTIMIZER_ITERATION_NAME, |
| shape=[1], |
| value=0, |
| dtype=core.DataType.INT64) |
| iter_mutex = param_init_net.CreateMutex([], |
| ["iteration_mutex"]) |
| net.AtomicIter([iter_mutex, iteration], [iteration]) |
| else: |
| iteration = param_init_net.GetBlobRef(_OPTIMIZER_ITERATION_NAME) |
| |
| self._aux_params.shared.append(iteration) |
| self._aux_params.local.append(moment) |
| self._aux_params.local.append(lr_avg) |
| self._aux_params.local.append(mu_avg) |
| self._aux_params.local.append(curv_win) |
| self._aux_params.local.append(g_avg) |
| self._aux_params.local.append(g2_avg) |
| self._aux_params.local.append(scalars_memory) |
| |
| yf_in_out_args = [ |
| param, |
| moment, |
| lr_avg, |
| mu_avg, |
| curv_win, |
| g_avg, |
| g2_avg, |
| scalars_memory |
| ] |
| |
| net.YellowFin( |
| yf_in_out_args + [grad, iteration], |
| yf_in_out_args, |
| beta=self.beta, |
| epsilon=self.epsilon, |
| curv_win_width=self.curv_win_width, |
| zero_debias=self.zero_debias) |
| |
| def scale_learning_rate(self, scale): |
| self.alpha *= scale |
| return |
| |
| |
| def _get_param_to_device(model): |
| # Infer blob devices by going through the net and param_init_net |
| # ops and observing the device used to create or use the blob. |
| param_to_device = core.InferBlobDevices(model.net) |
| param_to_device.update(core.InferBlobDevices(model.param_init_net)) |
| return param_to_device |
| |
| |
| def get_param_device(param_name, grad, param_to_device=None, default_device=None): |
| device = default_device |
| param_to_device = param_to_device or {} |
| # We first check if parameter's device has been inferred. If not, |
| # we check the gradient. This can happen if parameter is not output |
| # by any blob but created by a FetchBlob. |
| if param_name in param_to_device: |
| device = param_to_device[param_name] |
| else: |
| if isinstance(grad, core.GradientSlice): |
| grad = grad |
| if str(grad.values) in param_to_device: |
| device = param_to_device[str(grad.values)] |
| elif str(grad.indices) in param_to_device: |
| device = param_to_device[str(grad.indices)] |
| else: |
| grad_name = str(grad) |
| if grad_name in param_to_device: |
| device = param_to_device[grad_name] |
| |
| assert device is not None,\ |
| "Cannot infer device for {}: no op creates it".format(param_name) |
| return device |
| |
| |
| def get_lr_injection(): |
| """ |
| Gets current value for lr_injection, a multiplier for all base |
| learning rates. |
| Must set allow_lr_injection=True when building optimizer, as it |
| relies on synchronization over CPU. |
| """ |
| return workspace.FetchBlob(_LEARNING_RATE_INJECTION) |
| |
| |
| def set_lr_injection(lr_injection_value): |
| """ |
| Sets lr_injection, a multiplier for all base learning rates. |
| Must set allow_lr_injection=True when building optimizer, as it |
| relies on synchronization over CPU. |
| """ |
| workspace.FeedBlob( |
| _LEARNING_RATE_INJECTION, |
| np.array( |
| [float(lr_injection_value)], |
| dtype=np.float32, |
| ), |
| ) |
| |
| |
| def _calc_norm_ratio( |
| model, params, name_scope, param_to_device, max_gradient_norm |
| ): |
| with core.NameScope(name_scope): |
| grad_squared_sums = [] |
| for i, param in enumerate(params): |
| device = get_param_device( |
| str(param.blob), param.grad, param_to_device |
| ) |
| |
| with core.DeviceScope(device): |
| grad = ( |
| param.grad |
| if not isinstance( |
| param.grad, |
| core.GradientSlice, |
| ) else param.grad.values |
| ) |
| |
| grad_squared_sum_name = 'grad_{}_squared_sum'.format(i) |
| grad_squared_sum = model.net.SumSqrElements( |
| grad, |
| grad_squared_sum_name, |
| ) |
| grad_squared_sum_cpu = model.net.EnsureCPUOutput( |
| grad_squared_sum |
| ) |
| grad_squared_sums.append(grad_squared_sum_cpu) |
| |
| with core.DeviceScope(core.DeviceOption(caffe2_pb2.CPU)): |
| grad_squared_full_sum = model.net.Sum( |
| grad_squared_sums, |
| 'grad_squared_full_sum', |
| ) |
| global_norm = model.net.Pow( |
| grad_squared_full_sum, |
| 'global_norm', |
| exponent=0.5, |
| ) |
| clip_norm = model.param_init_net.ConstantFill( |
| [], |
| 'clip_norm', |
| shape=[], |
| value=float(max_gradient_norm), |
| ) |
| max_norm = model.net.Max( |
| [global_norm, clip_norm], |
| 'max_norm', |
| ) |
| norm_ratio = model.net.Div( |
| [clip_norm, max_norm], |
| 'norm_ratio', |
| ) |
| return norm_ratio |
| |
| |
| def _build( |
| model, |
| optimizer, |
| weights_only=False, |
| use_param_info_optim=True, |
| max_gradient_norm=None, |
| allow_lr_injection=False, |
| ): |
| param_to_device = _get_param_to_device(model) |
| |
| # Validate there are no duplicate params |
| model.Validate() |
| |
| params = [] |
| for param_info in model.GetOptimizationParamInfo(): |
| if weights_only and param_info.blob not in model.weights: |
| continue |
| params.append(param_info) |
| |
| lr_multiplier = None |
| if max_gradient_norm is not None: |
| lr_multiplier = _calc_norm_ratio( |
| model, |
| params, |
| 'norm_clipped_grad_update', |
| param_to_device, |
| max_gradient_norm, |
| ) |
| |
| if allow_lr_injection: |
| if not model.net.BlobIsDefined(_LEARNING_RATE_INJECTION): |
| lr_injection = model.param_init_net.ConstantFill( |
| [], |
| _LEARNING_RATE_INJECTION, |
| shape=[1], |
| value=1.0, |
| ) |
| else: |
| lr_injection = _LEARNING_RATE_INJECTION |
| |
| if lr_multiplier is None: |
| lr_multiplier = lr_injection |
| else: |
| lr_multiplier = model.net.Mul( |
| [lr_multiplier, lr_injection], |
| 'lr_multiplier', |
| broadcast=1, |
| ) |
| optimizer.add_lr_multiplier(lr_multiplier) |
| |
| for param_info in params: |
| param_name = str(param_info.blob) |
| |
| device = get_param_device(param_name, param_info.grad, param_to_device) |
| |
| with core.DeviceScope(device): |
| if param_info.optimizer and use_param_info_optim: |
| param_info.optimizer(model.net, model.param_init_net, param_info) |
| else: |
| optimizer(model.net, model.param_init_net, param_info) |
| return optimizer |
| |
| |
| def add_weight_decay(model, weight_decay): |
| """Adds a decay to weights in the model. |
| |
| This is a form of L2 regularization. |
| |
| Args: |
| weight_decay: strength of the regularization |
| """ |
| _build( |
| model, |
| WeightDecayBuilder(weight_decay=weight_decay), |
| weights_only=True, |
| use_param_info_optim=False, |
| ) |
| |
| |
| def build_sgd( |
| model, |
| base_learning_rate, |
| max_gradient_norm=None, |
| allow_lr_injection=False, |
| **kwargs |
| ): |
| sgd_optimizer = SgdOptimizer(base_learning_rate, **kwargs) |
| return _build( |
| model, |
| sgd_optimizer, |
| max_gradient_norm=max_gradient_norm, |
| allow_lr_injection=allow_lr_injection, |
| ) |
| |
| |
| def build_multi_precision_sgd( |
| model, |
| base_learning_rate, |
| max_gradient_norm=None, |
| allow_lr_injection=False, |
| **kwargs |
| ): |
| multi_prec_sgd_optimizer = MultiPrecisionSgdOptimizer( |
| base_learning_rate, **kwargs |
| ) |
| return _build( |
| model, |
| multi_prec_sgd_optimizer, |
| max_gradient_norm=max_gradient_norm, |
| allow_lr_injection=allow_lr_injection, |
| ) |
| |
| |
| def build_ftrl(model, engine="SIMD", **kwargs): |
| if engine == "SIMD": |
| assert core.IsOperator('Ftrl_ENGINE_SIMD') |
| assert core.IsOperator('SparseFtrl_ENGINE_SIMD') |
| ftrl_optimizer = FtrlOptimizer(engine=engine, **kwargs) |
| return _build(model, ftrl_optimizer) |
| |
| |
| def build_adagrad( |
| model, |
| base_learning_rate, |
| parameters=None, |
| max_gradient_norm=None, |
| allow_lr_injection=False, |
| **kwargs |
| ): |
| adagrad_optimizer = AdagradOptimizer(alpha=base_learning_rate, **kwargs) |
| return _build( |
| model, |
| adagrad_optimizer, |
| max_gradient_norm=max_gradient_norm, |
| allow_lr_injection=allow_lr_injection, |
| ) |
| |
| |
| def build_adam( |
| model, |
| base_learning_rate, |
| max_gradient_norm=None, |
| allow_lr_injection=False, |
| **kwargs |
| ): |
| adam_optimizer = AdamOptimizer(alpha=base_learning_rate, **kwargs) |
| return _build( |
| model, |
| adam_optimizer, |
| max_gradient_norm=max_gradient_norm, |
| allow_lr_injection=allow_lr_injection, |
| ) |
| |
| |
| def build_yellowfin(model, base_learning_rate=0.1, **kwargs): |
| yellowfin_optimizer = YellowFinOptimizer( |
| alpha=base_learning_rate, |
| **kwargs) |
| return _build(model, yellowfin_optimizer) |
