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600 lines
25 KiB
600 lines
25 KiB
import torch
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import torch.nn.init as init
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from torch import Tensor
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from torch import distributed as dist
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from torch import nn as nn
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from torch.nn import functional as F
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from torch.nn.parameter import Parameter
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from colossalai.legacy.context import ParallelMode, seed
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from colossalai.legacy.core import global_context as gpc
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from colossalai.legacy.nn.layer.base_layer import ParallelLayer
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from colossalai.legacy.nn.layer.parallel_1d._utils import gather_forward_split_backward, reduce_grad, reduce_input
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from colossalai.legacy.nn.layer.parallel_1d.layers import Linear1D_Row
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from colossalai.legacy.nn.layer.utils import divide
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from colossalai.legacy.registry import LAYERS, LOSSES, MODELS
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from colossalai.utils import get_current_device
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class VocabParallelEmbedding(torch.nn.Module):
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"""Language model embeddings.
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Arguments:
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hidden_size: hidden size
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vocab_size: vocabulary size
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max_sequence_length: maximum size of sequence. This
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is used for positional embedding
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embedding_dropout_prob: dropout probability for embeddings
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init_method: weight initialization method
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num_tokentypes: size of the token-type embeddings. 0 value
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will ignore this embedding
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"""
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def __init__(self,
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hidden_size,
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vocab_size,
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max_sequence_length,
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embedding_dropout_prob,
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num_tokentypes=0,
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dtype=torch.float):
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super(VocabParallelEmbedding, self).__init__()
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self.hidden_size = hidden_size
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self.num_tokentypes = num_tokentypes
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# Word embeddings (parallel).
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self.word_embeddings = VocabParallelEmbedding1D(vocab_size, self.hidden_size, dtype=dtype)
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self._word_embeddings_key = 'word_embeddings'
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# Position embedding (serial).
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self.position_embeddings = torch.nn.Embedding(max_sequence_length, self.hidden_size, dtype=dtype)
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self._position_embeddings_key = 'position_embeddings'
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# Initialize the position embeddings.
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# self.init_method(self.position_embeddings.weight)
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# Token type embedding.
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# Add this as an optional field that can be added through
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# method call so we can load a pretrain model without
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# token types and add them as needed.
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self._tokentype_embeddings_key = 'tokentype_embeddings'
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if self.num_tokentypes > 0:
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self.tokentype_embeddings = torch.nn.Embedding(self.num_tokentypes, self.hidden_size, dtype=dtype)
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# Initialize the token-type embeddings.
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# self.init_method(self.tokentype_embeddings.weight)
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else:
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self.tokentype_embeddings = None
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# Embeddings dropout
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self.embedding_dropout = torch.nn.Dropout(embedding_dropout_prob)
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def zero_parameters(self):
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"""Zero out all parameters in embedding."""
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self.word_embeddings.weight.data.fill_(0)
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self.word_embeddings.weight.shared = True
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self.position_embeddings.weight.data.fill_(0)
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self.position_embeddings.weight.shared = True
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if self.num_tokentypes > 0:
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self.tokentype_embeddings.weight.data.fill_(0)
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self.tokentype_embeddings.weight.shared = True
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def add_tokentype_embeddings(self, num_tokentypes):
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"""Add token-type embedding. This function is provided so we can add
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token-type embeddings in case the pretrained model does not have it.
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This allows us to load the model normally and then add this embedding.
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"""
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if self.tokentype_embeddings is not None:
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raise Exception('tokentype embeddings is already initialized')
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if torch.distributed.get_rank() == 0:
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print('adding embedding for {} tokentypes'.format(num_tokentypes), flush=True)
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self.num_tokentypes = num_tokentypes
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self.tokentype_embeddings = torch.nn.Embedding(num_tokentypes, self.hidden_size)
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# Initialize the token-type embeddings.
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# self.init_method(self.tokentype_embeddings.weight)
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def forward(self, input_ids, position_ids=None, tokentype_ids=None):
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# Embeddings.
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if input_ids is not None:
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input_shape = input_ids.size()
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input_ids = input_ids.view(-1, input_shape[-1])
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words_embeddings = self.word_embeddings(input_ids)
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if position_ids is not None:
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position_ids = position_ids.view(-1, input_shape[-1])
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if position_ids is None:
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position_ids = torch.arange(0, input_shape[-1] + 0, dtype=torch.long, device=get_current_device())
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position_ids = position_ids.unsqueeze(0).view(-1, input_shape[-1])
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position_embeddings = self.position_embeddings(position_ids)
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embeddings = words_embeddings + position_embeddings
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# Dropout.
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with seed(ParallelMode.TENSOR):
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embeddings = self.embedding_dropout(embeddings)
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return embeddings
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def state_dict_for_save_checkpoint(self, destination=None, prefix='', keep_vars=False):
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"""For easy load."""
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state_dict_ = {}
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state_dict_[self._word_embeddings_key] \
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= self.word_embeddings.state_dict(destination, prefix, keep_vars)
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state_dict_[self._position_embeddings_key] \
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= self.position_embeddings.state_dict(
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destination, prefix, keep_vars)
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if self.num_tokentypes > 0:
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state_dict_[self._tokentype_embeddings_key] \
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= self.tokentype_embeddings.state_dict(
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destination, prefix, keep_vars)
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return state_dict_
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def load_state_dict(self, state_dict, strict=True):
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"""Customized load."""
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# Word embedding.
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if self._word_embeddings_key in state_dict:
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state_dict_ = state_dict[self._word_embeddings_key]
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else:
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# for backward compatibility.
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state_dict_ = {}
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for key in state_dict.keys():
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if 'word_embeddings' in key:
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state_dict_[key.split('word_embeddings.')[1]] \
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= state_dict[key]
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self.word_embeddings.load_state_dict(state_dict_, strict=strict)
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# Position embedding.
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if self._position_embeddings_key in state_dict:
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state_dict_ = state_dict[self._position_embeddings_key]
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else:
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# for backward compatibility.
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state_dict_ = {}
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for key in state_dict.keys():
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if 'position_embeddings' in key:
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state_dict_[key.split('position_embeddings.')[1]] \
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= state_dict[key]
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self.position_embeddings.load_state_dict(state_dict_, strict=strict)
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# Tokentype embedding.
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if self.num_tokentypes > 0:
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state_dict_ = {}
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if self._tokentype_embeddings_key in state_dict:
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state_dict_ = state_dict[self._tokentype_embeddings_key]
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else:
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# for backward compatibility.
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for key in state_dict.keys():
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if 'tokentype_embeddings' in key:
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state_dict_[key.split('tokentype_embeddings.')[1]] \
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= state_dict[key]
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if len(state_dict_.keys()) > 0:
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self.tokentype_embeddings.load_state_dict(state_dict_, strict=strict)
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else:
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print('***WARNING*** expected tokentype embeddings in the '
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'checkpoint but could not find it',
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flush=True)
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class VocabParallelEmbedding1D(torch.nn.Module):
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"""Embedding parallelized in the vocabulary dimension.
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This is mainly adapted from torch.nn.Embedding and all the default
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values are kept.
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Arguments:
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num_embeddings: vocabulary size.
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embedding_dim: size of hidden state.
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init_method: method to initialize weights.
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"""
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def __init__(self, num_embeddings, embedding_dim, dtype=None, init_method=None):
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super(VocabParallelEmbedding1D, self).__init__()
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# Keep the input dimensions.
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self.num_embeddings = num_embeddings
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self.embedding_dim = embedding_dim
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# Set the details for compatibility.
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self.padding_idx = None
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self.max_norm = None
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self.norm_type = 2.
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self.scale_grad_by_freq = False
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self.sparse = False
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self._weight = None
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self.tensor_model_parallel_size = gpc.tensor_parallel_size
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# Divide the weight matrix along the vocabulary dimension.
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self.vocab_start_index, self.vocab_end_index = \
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VocabUtility.vocab_range_from_global_vocab_size(
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self.num_embeddings, gpc.get_local_rank(ParallelMode.PARALLEL_1D),
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self.tensor_model_parallel_size)
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self.num_embeddings_per_partition = self.vocab_end_index - \
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self.vocab_start_index
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# Allocate weights and initialize.
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factory_kwargs = {'device': get_current_device(), 'dtype': dtype}
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self.weight = Parameter(torch.empty(self.num_embeddings_per_partition, self.embedding_dim, **factory_kwargs))
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init.uniform_(self.weight, -1, 1)
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def forward(self, input_):
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if self.tensor_model_parallel_size > 1:
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# Build the mask.
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input_mask = (input_ < self.vocab_start_index) | \
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(input_ >= self.vocab_end_index)
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# Mask the input.
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masked_input = input_.clone() - self.vocab_start_index
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masked_input[input_mask] = 0
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else:
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masked_input = input_
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# Get the embeddings.
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output_parallel = F.embedding(masked_input, self.weight, self.padding_idx, self.max_norm, self.norm_type,
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self.scale_grad_by_freq, self.sparse)
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# Mask the output embedding.
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if self.tensor_model_parallel_size > 1:
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output_parallel[input_mask, :] = 0.0
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# Reduce across all the model parallel GPUs.
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output = output = reduce_input(output_parallel, ParallelMode.PARALLEL_1D)
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return output
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@LOSSES.register_module
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class vocab_parallel_cross_entropy(nn.Module):
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def __init__(self):
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super().__init__()
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def forward(self, vocab_parallel_logits, target):
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"""Helper function for the cross entropy."""
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vocab_parallel_logits = vocab_parallel_logits[..., :-1, :].contiguous()
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target = target[..., 1:].contiguous()
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return _VocabParallelCrossEntropy.apply(vocab_parallel_logits.view(-1, vocab_parallel_logits.size(-1)),
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target.view(-1))
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class _VocabParallelCrossEntropy(torch.autograd.Function):
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@staticmethod
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def forward(ctx, vocab_parallel_logits, target):
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# Maximum value along vocab dimension across all GPUs.
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logits_max = torch.max(vocab_parallel_logits, dim=-1)[0]
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torch.distributed.all_reduce(logits_max,
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op=torch.distributed.ReduceOp.MAX,
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group=gpc.get_group(ParallelMode.PARALLEL_1D))
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# Subtract the maximum value.
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vocab_parallel_logits.sub_(logits_max.unsqueeze(dim=-1))
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# Get the partition's vocab indices
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get_vocab_range = VocabUtility.vocab_range_from_per_partition_vocab_size
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partition_vocab_size = vocab_parallel_logits.size()[-1]
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rank = gpc.get_local_rank(ParallelMode.PARALLEL_1D)
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world_size = gpc.tensor_parallel_size
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vocab_start_index, vocab_end_index = get_vocab_range(partition_vocab_size, rank, world_size)
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# Create a mask of valid vocab ids (1 means it needs to be masked).
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target_mask = (target < vocab_start_index) | (target >= vocab_end_index)
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masked_target = target.clone() - vocab_start_index
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masked_target[target_mask] = 0
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# Get predicted-logits = logits[target].
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# For Simplicity, we convert logits to a 2-D tensor with size
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# [*, partition-vocab-size] and target to a 1-D tensor of size [*].
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logits_2d = vocab_parallel_logits.view(-1, partition_vocab_size)
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masked_target_1d = masked_target.view(-1)
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arange_1d = torch.arange(start=0, end=logits_2d.size()[0], device=logits_2d.device)
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predicted_logits_1d = logits_2d[arange_1d, masked_target_1d]
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predicted_logits_1d = predicted_logits_1d.clone().contiguous()
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predicted_logits = predicted_logits_1d.view_as(target)
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predicted_logits[target_mask] = 0.0
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# All reduce is needed to get the chunks from other GPUs.
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torch.distributed.all_reduce(predicted_logits,
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op=torch.distributed.ReduceOp.SUM,
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group=gpc.get_group(ParallelMode.PARALLEL_1D))
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# Sum of exponential of logits along vocab dimension across all GPUs.
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exp_logits = vocab_parallel_logits
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torch.exp(vocab_parallel_logits, out=exp_logits)
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sum_exp_logits = exp_logits.sum(dim=-1)
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torch.distributed.all_reduce(sum_exp_logits,
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op=torch.distributed.ReduceOp.SUM,
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group=gpc.get_group(ParallelMode.PARALLEL_1D))
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# Loss = log(sum(exp(logits))) - predicted-logit.
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loss = torch.log(sum_exp_logits) - predicted_logits
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loss = loss.mean()
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# Store softmax, target-mask and masked-target for backward pass.
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exp_logits.div_(sum_exp_logits.unsqueeze(dim=-1))
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ctx.save_for_backward(exp_logits, target_mask, masked_target_1d)
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return loss
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@staticmethod
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def backward(ctx, grad_output):
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# Retrieve tensors from the forward path.
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softmax, target_mask, masked_target_1d = ctx.saved_tensors
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# All the inputs have softmax as their gradient.
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grad_input = softmax
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# For simplicity, work with the 2D gradient.
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partition_vocab_size = softmax.size()[-1]
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grad_2d = grad_input.view(-1, partition_vocab_size)
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# Add the gradient from matching classes.
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arange_1d = torch.arange(start=0, end=grad_2d.size()[0], device=grad_2d.device)
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grad_2d[arange_1d, masked_target_1d] -= (1.0 - target_mask.view(-1).float())
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# Finally elementwise multiplication with the output gradients.
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grad_input.mul_(grad_output.unsqueeze(dim=-1))
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return grad_input, None
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class VocabUtility:
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"""Split the vocabulary into `world_size` chunks amd return the
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first and last index of the vocabulary belonging to the `rank`
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partition: Note that indices in [fist, last)"""
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@staticmethod
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def vocab_range_from_per_partition_vocab_size(per_partition_vocab_size, rank, world_size):
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index_f = rank * per_partition_vocab_size
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index_l = index_f + per_partition_vocab_size
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return index_f, index_l
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@staticmethod
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def vocab_range_from_global_vocab_size(global_vocab_size, rank, world_size):
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per_partition_vocab_size = divide(global_vocab_size, world_size)
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return VocabUtility.vocab_range_from_per_partition_vocab_size(per_partition_vocab_size, rank, world_size)
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class VocabParallelGPTLMHead1D(ParallelLayer):
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"""
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Language model head that shares the same parameters with the embedding matrix.
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"""
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def __init__(self, embed=None, vocab_size=None, dtype=None, embed_dim=None):
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super().__init__()
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if embed is not None:
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self.head = embed
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else:
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self.head = VocabParallelEmbedding1D(vocab_size, embed_dim, dtype=dtype)
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def forward(self, x: Tensor) -> Tensor:
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x = reduce_grad(x, ParallelMode.PARALLEL_1D)
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x = F.linear(x, self.head.weight)
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return x
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###################################
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class HiddenParallelEmbedding(torch.nn.Module):
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"""Language model embeddings.
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Arguments:
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hidden_size: hidden size
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vocab_size: vocabulary size
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max_sequence_length: maximum size of sequence. This
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is used for positional embedding
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embedding_dropout_prob: dropout probability for embeddings
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init_method: weight initialization method
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num_tokentypes: size of the token-type embeddings. 0 value
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will ignore this embedding
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"""
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def __init__(
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self,
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hidden_size,
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vocab_size,
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max_sequence_length,
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embedding_dropout_prob,
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dtype=torch.float,
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padding_idx: int = 0,
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num_tokentypes=0,
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):
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super(HiddenParallelEmbedding, self).__init__()
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self.hidden_size = hidden_size
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self.num_tokentypes = num_tokentypes
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# Word embeddings (parallel).
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self.word_embeddings = HiddenParallelEmbedding1D(vocab_size, hidden_size, dtype, padding_idx)
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self._word_embeddings_key = 'word_embeddings'
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# Position embedding (serial).
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self.position_embeddings = torch.nn.Embedding(max_sequence_length, self.hidden_size)
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self._position_embeddings_key = 'position_embeddings'
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# Initialize the position embeddings.
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# self.init_method(self.position_embeddings.weight)
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# Token type embedding.
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# Add this as an optional field that can be added through
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# method call so we can load a pretrain model without
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# token types and add them as needed.
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self._tokentype_embeddings_key = 'tokentype_embeddings'
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if self.num_tokentypes > 0:
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self.tokentype_embeddings = torch.nn.Embedding(self.num_tokentypes, self.hidden_size)
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# Initialize the token-type embeddings.
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# self.init_method(self.tokentype_embeddings.weight)
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else:
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self.tokentype_embeddings = None
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# Embeddings dropout
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self.embedding_dropout = torch.nn.Dropout(embedding_dropout_prob)
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def zero_parameters(self):
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"""Zero out all parameters in embedding."""
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self.word_embeddings.weight.data.fill_(0)
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self.word_embeddings.weight.shared = True
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self.position_embeddings.weight.data.fill_(0)
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self.position_embeddings.weight.shared = True
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if self.num_tokentypes > 0:
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self.tokentype_embeddings.weight.data.fill_(0)
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self.tokentype_embeddings.weight.shared = True
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def add_tokentype_embeddings(self, num_tokentypes):
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"""Add token-type embedding. This function is provided so we can add
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token-type embeddings in case the pretrained model does not have it.
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This allows us to load the model normally and then add this embedding.
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"""
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if self.tokentype_embeddings is not None:
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raise Exception('tokentype embeddings is already initialized')
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if torch.distributed.get_rank() == 0:
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print('adding embedding for {} tokentypes'.format(num_tokentypes), flush=True)
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|
self.num_tokentypes = num_tokentypes
|
|
self.tokentype_embeddings = torch.nn.Embedding(num_tokentypes, self.hidden_size)
|
|
# Initialize the token-type embeddings.
|
|
# self.init_method(self.tokentype_embeddings.weight)
|
|
|
|
def forward(self, input_ids, position_ids=None, tokentype_ids=None):
|
|
if input_ids is not None:
|
|
input_shape = input_ids.size()
|
|
input_ids = input_ids.view(-1, input_shape[-1])
|
|
words_embeddings = self.word_embeddings(input_ids)
|
|
|
|
if position_ids is not None:
|
|
position_ids = position_ids.view(-1, input_shape[-1])
|
|
if position_ids is None:
|
|
position_ids = torch.arange(0, input_shape[-1] + 0, dtype=torch.long, device=get_current_device())
|
|
position_ids = position_ids.unsqueeze(0).view(-1, input_shape[-1])
|
|
position_embeddings = self.position_embeddings(position_ids)
|
|
|
|
embeddings = words_embeddings + position_embeddings
|
|
|
|
# Dropout.
|
|
with seed(ParallelMode.TENSOR):
|
|
embeddings = self.embedding_dropout(embeddings)
|
|
return embeddings
|
|
|
|
def state_dict_for_save_checkpoint(self, destination=None, prefix='', keep_vars=False):
|
|
"""For easy load."""
|
|
|
|
state_dict_ = {}
|
|
state_dict_[self._word_embeddings_key] \
|
|
= self.word_embeddings.state_dict(destination, prefix, keep_vars)
|
|
state_dict_[self._position_embeddings_key] \
|
|
= self.position_embeddings.state_dict(
|
|
destination, prefix, keep_vars)
|
|
if self.num_tokentypes > 0:
|
|
state_dict_[self._tokentype_embeddings_key] \
|
|
= self.tokentype_embeddings.state_dict(
|
|
destination, prefix, keep_vars)
|
|
|
|
return state_dict_
|
|
|
|
def load_state_dict(self, state_dict, strict=True):
|
|
"""Customized load."""
|
|
|
|
# Word embedding.
|
|
if self._word_embeddings_key in state_dict:
|
|
state_dict_ = state_dict[self._word_embeddings_key]
|
|
else:
|
|
# for backward compatibility.
|
|
state_dict_ = {}
|
|
for key in state_dict.keys():
|
|
if 'word_embeddings' in key:
|
|
state_dict_[key.split('word_embeddings.')[1]] \
|
|
= state_dict[key]
|
|
self.word_embeddings.load_state_dict(state_dict_, strict=strict)
|
|
|
|
# Position embedding.
|
|
if self._position_embeddings_key in state_dict:
|
|
state_dict_ = state_dict[self._position_embeddings_key]
|
|
else:
|
|
# for backward compatibility.
|
|
state_dict_ = {}
|
|
for key in state_dict.keys():
|
|
if 'position_embeddings' in key:
|
|
state_dict_[key.split('position_embeddings.')[1]] \
|
|
= state_dict[key]
|
|
self.position_embeddings.load_state_dict(state_dict_, strict=strict)
|
|
|
|
# Tokentype embedding.
|
|
if self.num_tokentypes > 0:
|
|
state_dict_ = {}
|
|
if self._tokentype_embeddings_key in state_dict:
|
|
state_dict_ = state_dict[self._tokentype_embeddings_key]
|
|
else:
|
|
# for backward compatibility.
|
|
for key in state_dict.keys():
|
|
if 'tokentype_embeddings' in key:
|
|
state_dict_[key.split('tokentype_embeddings.')[1]] \
|
|
= state_dict[key]
|
|
if len(state_dict_.keys()) > 0:
|
|
self.tokentype_embeddings.load_state_dict(state_dict_, strict=strict)
|
|
else:
|
|
print('***WARNING*** expected tokentype embeddings in the '
|
|
'checkpoint but could not find it',
|
|
flush=True)
|
|
|
|
|
|
class HiddenParallelEmbedding1D(torch.nn.Module):
|
|
"""Embedding parallelized in the vocabulary dimension.
|
|
|
|
This is mainly adapted from torch.nn.Embedding and all the default
|
|
values are kept.
|
|
Arguments:
|
|
num_embeddings: vocabulary size.
|
|
embedding_dim: size of hidden state.
|
|
init_method: method to initialize weights.
|
|
"""
|
|
|
|
def __init__(self, num_embeddings, embedding_dim, dtype=torch.float, padding_idx: int = None, init_method=None):
|
|
super(HiddenParallelEmbedding1D, self).__init__()
|
|
# Keep the input dimensions.
|
|
self.num_embeddings = num_embeddings
|
|
self.embedding_dim = embedding_dim
|
|
embed_dim_per_partition = divide(embedding_dim, gpc.tensor_parallel_size)
|
|
# Set the details for compatibility.
|
|
self.padding_idx = padding_idx
|
|
self.max_norm = None
|
|
self.norm_type = 2.
|
|
self.scale_grad_by_freq = False
|
|
self.sparse = False
|
|
self._weight = None
|
|
|
|
# Allocate weights and initialize.
|
|
factory_kwargs = {'device': get_current_device(), 'dtype': dtype}
|
|
self.weight = Parameter(torch.empty(num_embeddings, embed_dim_per_partition, **factory_kwargs))
|
|
init.uniform_(self.weight, -1, 1)
|
|
|
|
def forward(self, input_):
|
|
|
|
# Get the embeddings.
|
|
output_parallel = F.embedding(input_, self.weight, self.padding_idx, self.max_norm, self.norm_type,
|
|
self.scale_grad_by_freq, self.sparse)
|
|
|
|
# Reduce across all the model parallel GPUs.
|
|
output = gather_forward_split_backward(output_parallel, ParallelMode.PARALLEL_1D, dim=-1)
|
|
return output
|
|
|
|
|
|
@LAYERS.register_module
|
|
class HiddenParallelGPTLMHead1D(ParallelLayer):
|
|
"""
|
|
Language model head that shares the same parameters with the embedding matrix.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
embed=None,
|
|
embed_dim=None,
|
|
vocab_size=None,
|
|
dtype=None,
|
|
):
|
|
super().__init__()
|
|
if embed is not None:
|
|
self.head = embed
|
|
self.synced_embed = True
|
|
else:
|
|
# self.embedding = HiddenParallelEmbedding1D(vocab_size, hidden_size, dtype, padding_idx)
|
|
# (hidden_size/q, vocab_size)
|
|
self.synced_embed = False
|
|
self.head = Linear1D_Row(in_features=embed_dim,
|
|
out_features=vocab_size,
|
|
bias=False,
|
|
dtype=dtype,
|
|
parallel_input=False)
|
|
|
|
def forward(self, x: Tensor) -> Tensor:
|
|
if self.synced_embed:
|
|
x = F.linear(x, self.head.weight)
|
|
else:
|
|
x = self.head(x)
|
|
|
|
return x
|