# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved. # # 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. import types import warnings import paddle from paddle.fluid import ( core, default_main_program, default_startup_program, layers, program_guard, unique_name, ) from .amp_nn import check_finite_and_unscale, update_loss_scaling from .fp16_lists import AutoMixedPrecisionLists from .fp16_utils import ( cast_model_to_fp16, cast_parameters_to_fp16, rewrite_program, update_role_var_grad, ) __all__ = ["decorate"] class OptimizerWithMixedPrecision: """ Optimizer with mixed-precision (MP) training. This is a wrapper of a common optimizer, plus the support of mixed-precision pre-training. The object of this class almost has the same behavior as the common optimizer, with the methods `minimize()`, `backward()`, `apply_gradients()` implemented. Additionally, it enables the MP training automatically, i.e, the creation and maintenance of master parameters, scaling of loss, etc. Args: optimizer (Optimizer): A common Optimizer object. amp_lists (CustomOpLists): An CustomOpLists object. init_loss_scaling (float): The initial loss scaling factor. use_dynamic_loss_scaling (bool): Whether to use dynamic loss scaling. incr_every_n_steps(int): Increases loss scaling every n consecutive steps with finite gradients. decr_every_n_nan_or_inf(int): Decreases loss scaling every n accumulated steps with nan or inf gradients. incr_ratio(float): The multiplier to use when increasing the loss scaling. decr_ratio(float): The less-than-one-multiplier to use when decreasing the loss scaling. use_pure_fp16(bool): Whether to use the pure fp16 training. Default False. use_fp16_guard(bool): Whether to use `fp16_guard` when constructing the program. Default None, which means that its value is equal to `use_pure_fp16`. """ def __init__( self, optimizer, amp_lists, init_loss_scaling, use_dynamic_loss_scaling, incr_every_n_steps, decr_every_n_nan_or_inf, incr_ratio, decr_ratio, use_pure_fp16, use_fp16_guard, ): self._optimizer = optimizer self._amp_lists = amp_lists self._param_grads = None self._train_program = None self._is_distributed = False self._scaled_loss = None self._loss_scaling = None self._init_loss_scaling = init_loss_scaling self._use_dynamic_loss_scaling = use_dynamic_loss_scaling self._learning_rate = optimizer._learning_rate self._learning_rate_map = optimizer._learning_rate_map self._use_pure_fp16 = use_pure_fp16 self._use_fp16_guard = use_fp16_guard self._to_fp16_var_names = None if self._use_dynamic_loss_scaling: self._incr_every_n_steps = incr_every_n_steps self._decr_every_n_nan_or_inf = decr_every_n_nan_or_inf self._incr_ratio = incr_ratio self._decr_ratio = decr_ratio self._num_good_steps = None self._num_bad_steps = None def _set_distributed(self, flag): # if distributed, all cards will communication with each other, # overlap communication and computation by split the # check_finite_and_unscale op. self._is_distributed = flag def get_loss_scaling(self): """Return the real-time loss scaling factor.""" assert ( self._loss_scaling is not None ), 'Please call minimize() before calling get_loss_scaling().' return self._loss_scaling def get_scaled_loss(self): """Return the scaled loss. It's useful when you feed customed loss into executor. """ return self._scaled_loss def _supports_check_nan_inf(self): return getattr(self._optimizer, "_supports_check_nan_inf", False) def _init_amp_var(self): self._loss_scaling = paddle.static.create_global_var( name=unique_name.generate("loss_scaling"), shape=[1], value=self._init_loss_scaling, dtype='float32', persistable=True, ) if self._use_dynamic_loss_scaling: self._num_good_steps = paddle.static.create_global_var( name=unique_name.generate("num_good_steps"), shape=[1], value=0, dtype='int32', persistable=True, ) self._num_bad_steps = paddle.static.create_global_var( name=unique_name.generate("num_bad_steps"), shape=[1], value=0, dtype='int32', persistable=True, ) # Ensure the data type of learning rate vars is float32 (same as the # master parameter dtype) if isinstance(self._optimizer._learning_rate, float): self._optimizer._learning_rate_map[ default_main_program() ] = paddle.static.create_global_var( name=unique_name.generate("learning_rate"), shape=[1], value=float(self._optimizer._learning_rate), dtype='float32', persistable=True, ) def backward( self, loss, startup_program=None, parameter_list=None, no_grad_set=None, callbacks=None, ): """ Backward propagation or auto differentiation for gradients' computation. Args: loss (Variable): The loss Variable to minimize. startup_program (Program|None): The startup Program for initializing parameters in `parameter_list`. parameter_list (list|None): A list of Variables to update. no_grad_set (set|None): A set of Variables should be ignored. callbacks (list|None): A list of callable objects to run when appending backward operator for one parameter. Returns: A list of (param, grad), which is a tuple of a parameter and its gradient respectively, and the scaled loss. """ train_program = loss.block.program self._train_program = train_program # NOTE(zhiqiu): _float_status is only used for NPU. if core.is_compiled_with_npu(): float_status = paddle.static.data( name="float_status", shape=[8], dtype='float32' ) self._train_program.global_block().append_op( type="alloc_float_status", outputs={"FloatStatus": float_status}, ) self._train_program.global_block().append_op( type="clear_float_status", inputs={"FloatStatus": float_status}, outputs={"FloatStatusOut": float_status}, ) self._float_status = float_status else: self._float_status = None with program_guard(self._train_program, startup_program): self._init_amp_var() if self._use_pure_fp16: self._to_fp16_var_names = cast_model_to_fp16( self._train_program, self._amp_lists, self._use_fp16_guard ) else: rewrite_program(self._train_program, self._amp_lists) if loss.dtype != core.VarDesc.VarType.FP32: loss = loss.astype('float32') # When not using dynamic loss scaling and the init loss scaling value is equal to 1.0, # the model can be optimized. if self._use_dynamic_loss_scaling or self._init_loss_scaling != 1.0: self._scaled_loss = loss * self._loss_scaling else: self._scaled_loss = loss params_grads = self._optimizer.backward( self._scaled_loss, startup_program, parameter_list, no_grad_set, callbacks, ) if self._supports_check_nan_inf(): self._add_cast_ops_to_startup_program(startup_program) return params_grads def _add_cast_ops_to_startup_program(self, startup_program): names = list(self._to_fp16_var_names) if self._to_fp16_var_names else [] names.sort() startup_program = ( default_startup_program() if startup_program is None else startup_program ) block = startup_program.global_block() param_names = [p.name for p in block.all_parameters()] for name in names: if name not in param_names: continue tmp = block.create_var(dtype=core.VarDesc.VarType.FP32) block.append_op( type='assign', inputs={'X': [name]}, outputs={'Out': [tmp]} ) block.append_op( type='cast', inputs={'X': [tmp]}, outputs={'Out': [name]}, attrs={ 'in_dtype': core.VarDesc.VarType.FP32, 'out_dtype': core.VarDesc.VarType.FP16, }, ) self._to_fp16_var_names = None def amp_init( self, place, scope=None, test_program=None, use_fp16_test=False ): """ Init the amp training, such as cast fp32 parameters to fp16 type. Args: place(CUDAPlace): place is used to initialize fp16 parameters with fp32 values. scope(Scope): The scope is used to find fp32 parameters. test_program(Program): The program is used for testing. use_fp16_test(bool): Whether to use fp16 testing. Examples: .. code-block:: python import numpy as np import paddle import paddle.nn.functional as F paddle.enable_static() def run_example_code(): place = paddle.CUDAPlace(0) exe = paddle.static.Executor(place) data = paddle.static.data(name='X', shape=[None, 1, 28, 28], dtype='float32') conv2d = paddle.static.nn.conv2d(input=data, num_filters=6, filter_size=3) # 1) Use fp16_guard to control the range of fp16 kernels used. with paddle.static.amp.fp16_guard(): bn = paddle.static.nn.batch_norm(input=conv2d, act="relu") pool = F.max_pool2d(bn, kernel_size=2, stride=2) hidden = paddle.static.nn.fc(pool, size=10) loss = paddle.mean(hidden) # 2) Create the optimizer and set `multi_precision` to True. # Setting `multi_precision` to True can avoid the poor accuracy # or the slow convergence in a way. optimizer = paddle.optimizer.Momentum(learning_rate=0.01, multi_precision=True) # 3) These ops in `custom_black_list` will keep in the float32 computation type. amp_list = paddle.static.amp.CustomOpLists( custom_black_list=['pool2d']) # 4) The entry of Paddle AMP. # Enable pure fp16 training by setting `use_pure_fp16` to True. optimizer = paddle.static.amp.decorate( optimizer, amp_list, init_loss_scaling=128.0, use_dynamic_loss_scaling=True, use_pure_fp16=True) # If you don't use the default_startup_program(), you sholud pass # your defined `startup_program` into `minimize`. optimizer.minimize(loss) exe.run(paddle.static.default_startup_program()) # 5) Use `amp_init` after FP32 parameters initialization(such as `exe.run(startup_program)`). # If you want to perform the testing process, you should pass `test_program` into `amp_init`. optimizer.amp_init(place, scope=paddle.static.global_scope()) if paddle.is_compiled_with_cuda() and len(paddle.static.cuda_places()) > 0: run_example_code() """ assert ( self._train_program is not None ), "Please call the minimize method first." if self._use_pure_fp16: cast_parameters_to_fp16( place, self._train_program, scope, self._to_fp16_var_names ) if test_program is not None: if self._use_pure_fp16: cast_model_to_fp16( test_program, self._amp_lists, self._use_fp16_guard ) elif use_fp16_test: rewrite_program(test_program, self._amp_lists) def apply_gradients(self, params_grads): """ Check scaled gradients to determine whether to update loss scaling and update parameters by their scaled gradients. Args: params_grads (list): A list of params and scaled grads. Returns: A list of optimize operators. """ # Change the op_role_var attr for some ops, so that gradients # transferred across GPUs can be FP16. update_role_var_grad(self._train_program, params_grads) # When not using dynamic loss scaling and the init loss scaling value is equal to 1.0, # the model can be optimized. if ( not self._use_dynamic_loss_scaling and self._init_loss_scaling == 1.0 ): return self._optimizer.apply_gradients(params_grads) if self._supports_check_nan_inf(): self._optimizer._set_scale(self._loss_scaling) optimize_ops = self._optimizer.apply_gradients(params_grads) found_inf = self._optimizer._found_inf self._add_dynamic_loss_scaling(params_grads, found_inf) return optimize_ops found_inf = self._check_finite_and_unscale(params_grads) if self._use_dynamic_loss_scaling: self._add_dynamic_loss_scaling(params_grads, found_inf) # Pass found_inf to adam, to skip update for not only param, but also momentum and beta_pow # With fleet, optimizers are nested and the real optimizer set by user is the inner most one. real_optimizer = self._optimizer while hasattr(real_optimizer, "inner_opt"): real_optimizer = real_optimizer.inner_opt if isinstance( real_optimizer, (paddle.fluid.optimizer.Adam, paddle.optimizer.AdamW), ): # NOTE(zhiqiu): Since found_inf needs to be on cpu in adam op, we # copy it in advance to avoid multiple time copies. with self._train_program._optimized_guard([]): found_inf = paddle.tensor.creation._memcpy( found_inf, paddle.CPUPlace() ) real_optimizer._set_auxiliary_var('found_inf', found_inf) elif hasattr(real_optimizer, "_set_auxiliary_var"): real_optimizer._set_auxiliary_var('found_inf', found_inf) optimize_ops = self._optimizer.apply_gradients(params_grads) return optimize_ops def _split_grads(self, params_grads): grads = [g for _, g in params_grads] fp32_grads = [g for g in grads if g.dtype == core.VarDesc.VarType.FP32] fp16_grads = [g for g in grads if g.dtype == core.VarDesc.VarType.FP16] assert len(fp32_grads) + len(fp16_grads) == len( grads ), "Data types of all grads must be either fp16 or fp32." return grads, fp32_grads, fp16_grads def _check_finite_and_unscale(self, params_grads): grads, fp32_grads, fp16_grads = self._split_grads(params_grads) found_infs = [] if self._is_distributed: # if distributed, split check_finite_and_unscale to overlap # unscale with communication if core.is_compiled_with_npu(): with self._train_program._optimized_guard(grads): _, found_inf = check_finite_and_unscale( grads, self._loss_scaling, name="find_infinite_scale", float_status=self._float_status, ) found_infs.append(found_inf) else: for p, g in params_grads: with self._train_program._optimized_guard([p, g]): _, found_inf = check_finite_and_unscale( [ g, ], self._loss_scaling, name="find_infinite_scale", float_status=self._float_status, ) found_infs.append(found_inf) elif self._use_pure_fp16: if fp32_grads: with self._train_program._optimized_guard(fp32_grads): _, fp32_found_inf = check_finite_and_unscale( fp32_grads, self._loss_scaling, name="find_infinite_scale_fp32", float_status=self._float_status, ) found_infs.append(fp32_found_inf) if fp16_grads: with self._train_program._optimized_guard(fp16_grads): _, fp16_found_inf = check_finite_and_unscale( fp16_grads, self._loss_scaling, name="find_infinite_scale_fp16", float_status=self._float_status, ) found_infs.append(fp16_found_inf) else: with self._train_program._optimized_guard(grads): _, found_inf = check_finite_and_unscale( grads, self._loss_scaling, name="find_infinite_scale", float_status=self._float_status, ) if self._is_distributed or self._use_pure_fp16: with self._train_program._optimized_guard([]): all_infs = layers.concat(found_infs) found_inf = paddle.any(all_infs) return found_inf def _add_dynamic_loss_scaling(self, params_grads, found_inf): if self._supports_check_nan_inf(): with self._train_program._optimized_guard([]): update_loss_scaling( [], found_inf, self._loss_scaling, self._num_good_steps, self._num_bad_steps, self._incr_every_n_steps, self._decr_every_n_nan_or_inf, self._incr_ratio, self._decr_ratio, stop_update=self._optimizer._get_stop_update_var(), name="update_loss_scaling", ) return grads, fp32_grads, fp16_grads = self._split_grads(params_grads) if self._use_pure_fp16: stop_update = False with self._train_program._optimized_guard([]): if fp32_grads: update_loss_scaling( fp32_grads, found_inf, self._loss_scaling, self._num_good_steps, self._num_bad_steps, self._incr_every_n_steps, self._decr_every_n_nan_or_inf, self._incr_ratio, self._decr_ratio, stop_update=stop_update, name="update_loss_scaling_fp32", ) stop_update = True if fp16_grads: update_loss_scaling( fp16_grads, found_inf, self._loss_scaling, self._num_good_steps, self._num_bad_steps, self._incr_every_n_steps, self._decr_every_n_nan_or_inf, self._incr_ratio, self._decr_ratio, stop_update=stop_update, name="update_loss_scaling_fp16", ) else: with self._train_program._optimized_guard([]): update_loss_scaling( grads, found_inf, self._loss_scaling, self._num_good_steps, self._num_bad_steps, self._incr_every_n_steps, self._decr_every_n_nan_or_inf, self._incr_ratio, self._decr_ratio, name="update_loss_scaling", ) def apply_optimize(self, loss, startup_program, params_grads): program = loss.block.program with program_guard(program, startup_program): optimize_ops = self.apply_gradients(params_grads) return optimize_ops def minimize( self, loss, startup_program=None, parameter_list=None, no_grad_set=None ): """ Perform optimization by minimizing the given loss. Args: loss (Variable): The loss Variable. startup_program (Program): startup_program for initializing parameters in `parameter_list`. parameter_list (list): list of Variables to update. no_grad_set (set|None): set of Variables should be ignored. Returns: The scaled loss by scaling factor, the list of optimize ops, and a list of scaled parameters and gradients. """ opt_dict = self._optimizer.__class__.__dict__ if 'minimize' in opt_dict and isinstance( opt_dict['minimize'], types.FunctionType ): warnings.warn( "The decorated optimizer has its own `minimize` method, but it will not be executed." ) scaled_params_grads = self.backward( loss, startup_program=startup_program, parameter_list=parameter_list, no_grad_set=no_grad_set, ) optimize_ops = self.apply_optimize( loss, startup_program, scaled_params_grads ) return optimize_ops, scaled_params_grads def decorate( optimizer, amp_lists=None, init_loss_scaling=2**15, incr_every_n_steps=1000, decr_every_n_nan_or_inf=2, incr_ratio=2.0, decr_ratio=0.8, use_dynamic_loss_scaling=True, use_pure_fp16=False, use_fp16_guard=None, ): """ Decorate the given optimizer to adapt to the mixed-precision training. Args: optimizer(Optimizer): A common Optimizer. amp_lists (CustomOpLists): An CustomOpLists object. init_loss_scaling(float): The initial loss scaling factor. incr_every_n_steps(int): Increases loss scaling every n consecutive steps with finite gradients. decr_every_n_nan_or_inf(int): Decreases loss scaling every n accumulated steps with nan or inf gradients. incr_ratio(float): The multiplier to use when increasing the loss scaling. decr_ratio(float): The less-than-one-multiplier to use when decreasing the loss scaling. use_dynamic_loss_scaling(bool): Whether to use dynamic loss scaling. use_pure_fp16(bool): Whether to use the pure fp16 training. Default False. use_fp16_guard(bool): Whether to use `fp16_guard` when constructing the program. Default None, which means that its value equals to `use_pure_fp16`. Returns: An optimizer acting like a normal one but with mixed-precision training enabled. Examples 1: .. code-block:: python # black&white list based strategy example import paddle import paddle.static as static paddle.enable_static() data = static.data(name='X', shape=[None, 1], dtype='float32') hidden = static.nn.fc(x=data, size=10) loss = paddle.mean(hidden) optimizer = paddle.optimizer.Adam(learning_rate=0.001) mp_optimizer = static.amp.decorate( optimizer=optimizer, init_loss_scaling=8.0) ops, param_grads = mp_optimizer.minimize(loss) scaled_loss = mp_optimizer.get_scaled_loss() Examples 2: .. code-block:: python # pure fp16 training example import numpy as np import paddle import paddle.nn.functional as F def run_example_code(): place = paddle.CUDAPlace(0) exe = paddle.static.Executor(place) data = paddle.static.data(name='X', shape=[None, 1, 28, 28], dtype='float32') conv2d = paddle.static.nn.conv2d(input=data, num_filters=6, filter_size=3) # 1) Use fp16_guard to control the range of fp16 kernels used. with paddle.static.amp.fp16_guard(): bn = paddle.static.nn.batch_norm(input=conv2d, act="relu") pool = F.max_pool2d(bn, kernel_size=2, stride=2) hidden = paddle.static.nn.fc(pool, size=10) loss = paddle.mean(hidden) # 2) Create the optimizer and set `multi_precision` to True. # Setting `multi_precision` to True can avoid the poor accuracy # or the slow convergence in a way. optimizer = paddle.optimizer.Momentum(learning_rate=0.01, multi_precision=True) # 3) These ops in `custom_black_list` will keep in the float32 computation type. amp_list = paddle.static.amp.CustomOpLists( custom_black_list=['pool2d']) # 4) The entry of Paddle AMP. # Enable pure fp16 training by setting `use_pure_fp16` to True. optimizer = paddle.static.amp.decorate( optimizer, amp_list, init_loss_scaling=128.0, use_dynamic_loss_scaling=True, use_pure_fp16=True) # If you don't use the default_startup_program(), you sholud pass # your defined `startup_program` into `minimize`. optimizer.minimize(loss) exe.run(paddle.static.default_startup_program()) # 5) Use `amp_init` after FP32 parameters initialization(such as `exe.run(startup_program)`). # If you want to perform the testing process, you should pass `test_program` into `amp_init`. optimizer.amp_init(place, scope=paddle.static.global_scope()) if paddle.is_compiled_with_cuda() and len(paddle.static.cuda_places()) > 0: run_example_code() """ if amp_lists is None: amp_lists = AutoMixedPrecisionLists() if use_fp16_guard is None: use_fp16_guard = use_pure_fp16 mp_optimizer = OptimizerWithMixedPrecision( optimizer, amp_lists, init_loss_scaling, use_dynamic_loss_scaling, incr_every_n_steps, decr_every_n_nan_or_inf, incr_ratio, decr_ratio, use_pure_fp16, use_fp16_guard, ) return mp_optimizer