vllm/vllm/model_executor/layers/vocab_parallel_embedding.py
2024-07-20 09:36:57 -07:00

406 lines
18 KiB
Python

from dataclasses import dataclass
from typing import List, Optional, Sequence, Tuple
import torch
import torch.nn.functional as F
from torch.nn.parameter import Parameter
from vllm.distributed import (divide, get_tensor_model_parallel_rank,
get_tensor_model_parallel_world_size,
tensor_model_parallel_all_reduce)
from vllm.model_executor.layers.linear import UnquantizedLinearMethod
from vllm.model_executor.layers.quantization.base_config import (
QuantizationConfig, QuantizeMethodBase)
from vllm.model_executor.utils import set_weight_attrs
DEFAULT_VOCAB_PADDING_SIZE = 64
def pad_vocab_size(vocab_size: int,
pad_to: int = DEFAULT_VOCAB_PADDING_SIZE) -> int:
"""Pad the vocab size to the given value."""
return ((vocab_size + pad_to - 1) // pad_to) * pad_to
def vocab_range_from_per_partition_vocab_size(
per_partition_vocab_size: int,
rank: int,
offset: int = 0) -> Sequence[int]:
index_f = rank * per_partition_vocab_size
index_l = index_f + per_partition_vocab_size
return index_f + offset, index_l + offset
def vocab_range_from_global_vocab_size(global_vocab_size: int,
rank: int,
world_size: int,
offset: int = 0) -> Sequence[int]:
per_partition_vocab_size = divide(global_vocab_size, world_size)
return vocab_range_from_per_partition_vocab_size(per_partition_vocab_size,
rank,
offset=offset)
@dataclass
class VocabParallelEmbeddingShardIndices:
"""Indices for a shard of a vocab parallel embedding."""
padded_org_vocab_start_index: int
padded_org_vocab_end_index: int
padded_added_vocab_start_index: int
padded_added_vocab_end_index: int
org_vocab_start_index: int
org_vocab_end_index: int
added_vocab_start_index: int
added_vocab_end_index: int
@property
def num_org_elements(self) -> int:
return self.org_vocab_end_index - self.org_vocab_start_index
@property
def num_added_elements(self) -> int:
return self.added_vocab_end_index - self.added_vocab_start_index
@property
def num_org_elements_padded(self) -> int:
return (self.padded_org_vocab_end_index -
self.padded_org_vocab_start_index)
@property
def num_added_elements_padded(self) -> int:
return (self.padded_added_vocab_end_index -
self.padded_added_vocab_start_index)
@property
def num_org_vocab_padding(self) -> int:
return self.num_org_elements_padded - self.num_org_elements
@property
def num_added_vocab_padding(self) -> int:
return self.num_added_elements_padded - self.num_added_elements
@property
def num_elements_padded(self) -> int:
return self.num_org_elements_padded + self.num_added_elements_padded
def __post_init__(self):
# sanity checks
assert (self.padded_org_vocab_start_index <=
self.padded_org_vocab_end_index)
assert (self.padded_added_vocab_start_index <=
self.padded_added_vocab_end_index)
assert self.org_vocab_start_index <= self.org_vocab_end_index
assert self.added_vocab_start_index <= self.added_vocab_end_index
assert self.org_vocab_start_index <= self.padded_org_vocab_start_index
assert (self.added_vocab_start_index <=
self.padded_added_vocab_start_index)
assert self.org_vocab_end_index <= self.padded_org_vocab_end_index
assert self.added_vocab_end_index <= self.padded_added_vocab_end_index
assert self.num_org_elements <= self.num_org_elements_padded
assert self.num_added_elements <= self.num_added_elements_padded
@torch.jit.script
def get_masked_input_and_mask(
input_: torch.Tensor, org_vocab_start_index: int,
org_vocab_end_index: int, num_org_vocab_padding: int,
added_vocab_start_index: int,
added_vocab_end_index: int) -> Tuple[torch.Tensor, torch.Tensor]:
# torch.jit.script will fuse all of the pointwise ops below
# into a single kernel, making it very fast
org_vocab_mask = (input_ >= org_vocab_start_index) & (input_ <
org_vocab_end_index)
added_vocab_mask = (input_ >= added_vocab_start_index) & (
input_ < added_vocab_end_index)
added_offset = added_vocab_start_index - (
org_vocab_end_index - org_vocab_start_index) - num_org_vocab_padding
valid_offset = (org_vocab_start_index *
org_vocab_mask) + (added_offset * added_vocab_mask)
vocab_mask = org_vocab_mask | added_vocab_mask
input_ = vocab_mask * (input_ - valid_offset)
return input_, ~vocab_mask
class VocabParallelEmbedding(torch.nn.Module):
"""Embedding parallelized in the vocabulary dimension.
Adapted from torch.nn.Embedding, note that we pad the vocabulary size to
make sure it is divisible by the number of model parallel GPUs.
In order to support various loading methods, we ensure that LoRA-added
embeddings are always at the end of TP-sharded tensors. In other words,
we shard base embeddings and LoRA embeddings separately (both padded),
and place them in the same tensor.
In this example, we will have the original vocab size = 1010,
added vocab size = 16 and padding to 64. Therefore, the total
vocab size with padding will be 1088 (because we first pad 1010 to
1024, add 16, and then pad to 1088).
Therefore, the tensor format looks like the following:
TP1, rank 0 (no sharding):
|< --------BASE-------- >|< -BASE PADDING-- >|< -----LORA------ >|< -LORA PADDING-- >|
corresponding token_id: | 0 | 1 | ... | 1009 | -1 | ... | -1 | 1010 | ... | 1015 | -1 | ... | -1 |
index: | 0 | 1 | ... | 1009 | 1010 | ... | 1023 | 1024 | ... | 1039 | 1040 | ... | 1087 |
TP2, rank 0:
|< --------------------BASE--------------------- >|< -----LORA------ >|< -LORA PADDING- >|
corresponding token_id: | 0 | 1 | 2 | ... | 497 | 498 | ... | 511 | 1000 | ... | 1015 | -1 | ... | -1 |
index: | 0 | 1 | 2 | ... | 497 | 498 | ... | 511 | 512 | ... | 527 | 520 | ... | 543 |
TP2, rank 1:
|< -----------BASE----------- >|< -BASE PADDING- >|< -----------LORA PADDING----------- >|
corresponding token_id: | 512 | 513 | 514 | ... | 1009 | -1 | ... | -1 | -1 | ... | -1 | -1 | ... | -1 |
index: | 0 | 1 | 2 | ... | 497 | 498 | ... | 511 | 512 | ... | 519 | 520 | ... | 543 |
Args:
num_embeddings: vocabulary size.
embedding_dim: size of hidden state.
params_dtype: type of the parameters.
org_num_embeddings: original vocabulary size (without LoRA).
padding_size: padding size for the vocabulary.
quant_config: quant config for the layer
prefix: full name of the layer in the state dict
""" # noqa: E501
def __init__(self,
num_embeddings: int,
embedding_dim: int,
params_dtype: Optional[torch.dtype] = None,
org_num_embeddings: Optional[int] = None,
padding_size: int = DEFAULT_VOCAB_PADDING_SIZE,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = ""):
super().__init__()
# Keep the input dimensions.
tp_rank = get_tensor_model_parallel_rank()
self.tp_size = get_tensor_model_parallel_world_size()
self.num_embeddings = num_embeddings
self.padding_size = padding_size
self.org_vocab_size = org_num_embeddings or num_embeddings
num_added_embeddings = num_embeddings - self.org_vocab_size
self.org_vocab_size_padded = pad_vocab_size(self.org_vocab_size,
self.padding_size)
self.num_embeddings_padded = pad_vocab_size(
self.org_vocab_size_padded + num_added_embeddings,
self.padding_size)
assert self.org_vocab_size_padded <= self.num_embeddings_padded
self.shard_indices = self._get_indices(self.num_embeddings_padded,
self.org_vocab_size_padded,
self.num_embeddings,
self.org_vocab_size, tp_rank,
self.tp_size)
self.embedding_dim = embedding_dim
linear_method = None
if quant_config is not None:
linear_method = quant_config.get_quant_method(self, prefix=prefix)
if linear_method is None:
linear_method = UnquantizedLinearMethod()
self.linear_method: QuantizeMethodBase = linear_method
if params_dtype is None:
params_dtype = torch.get_default_dtype()
# Divide the weight matrix along the vocaburaly dimension.
self.num_added_embeddings = self.num_embeddings - self.org_vocab_size
self.num_embeddings_per_partition = divide(self.num_embeddings_padded,
self.tp_size)
assert (self.shard_indices.num_elements_padded ==
self.num_embeddings_per_partition)
self.num_org_embeddings_per_partition = (
self.shard_indices.org_vocab_end_index -
self.shard_indices.org_vocab_start_index)
self.num_added_embeddings_per_partition = (
self.shard_indices.added_vocab_end_index -
self.shard_indices.added_vocab_start_index)
self.linear_method.create_weights(self,
self.embedding_dim,
[self.num_embeddings_per_partition],
self.embedding_dim,
self.num_embeddings_padded,
params_dtype=params_dtype,
weight_loader=self.weight_loader)
@classmethod
def _get_indices(cls, vocab_size_padded: int, org_vocab_size_padded: int,
vocab_size: int, org_vocab_size: int, tp_rank: int,
tp_size: int) -> VocabParallelEmbeddingShardIndices:
"""Get start and end indices for vocab parallel embedding, following the
layout outlined in the class docstring, based on the given tp_rank and
tp_size."""
num_added_embeddings_padded = vocab_size_padded - org_vocab_size_padded
padded_org_vocab_start_index, padded_org_vocab_end_index = (
vocab_range_from_global_vocab_size(org_vocab_size_padded, tp_rank,
tp_size))
padded_added_vocab_start_index, padded_added_vocab_end_index = (
vocab_range_from_global_vocab_size(num_added_embeddings_padded,
tp_rank,
tp_size,
offset=org_vocab_size))
# remove padding
org_vocab_start_index = min(padded_org_vocab_start_index,
org_vocab_size)
org_vocab_end_index = min(padded_org_vocab_end_index, org_vocab_size)
added_vocab_start_index = min(padded_added_vocab_start_index,
vocab_size)
added_vocab_end_index = min(padded_added_vocab_end_index, vocab_size)
return VocabParallelEmbeddingShardIndices(
padded_org_vocab_start_index, padded_org_vocab_end_index,
padded_added_vocab_start_index, padded_added_vocab_end_index,
org_vocab_start_index, org_vocab_end_index,
added_vocab_start_index, added_vocab_end_index)
def get_sharded_to_full_mapping(self) -> Optional[List[int]]:
"""Get a mapping that can be used to reindex the gathered
logits for sampling.
During sampling, we gather logits from all ranks. The relationship
of index->token_id will follow the same format as outlined in the class
docstring. However, after the gather, we want to reindex the final
logits tensor to map index->token_id one-to-one (the index is always
equal the token_id it corresponds to). The indices returned by this
method allow us to do that.
"""
if self.tp_size < 2:
return None
base_embeddings: List[int] = []
added_embeddings: List[int] = []
padding: List[int] = []
for tp_rank in range(self.tp_size):
shard_indices = self._get_indices(self.num_embeddings_padded,
self.org_vocab_size_padded,
self.num_embeddings,
self.org_vocab_size, tp_rank,
self.tp_size)
range_start = self.num_embeddings_per_partition * tp_rank
range_end = self.num_embeddings_per_partition * (tp_rank + 1)
base_embeddings.extend(
range(range_start,
range_start + shard_indices.num_org_elements))
padding.extend(
range(range_start + shard_indices.num_org_elements,
range_start + shard_indices.num_org_elements_padded))
added_embeddings.extend(
range(
range_start + shard_indices.num_org_elements_padded,
range_start + shard_indices.num_org_elements_padded +
shard_indices.num_added_elements))
padding.extend(
range(
range_start + shard_indices.num_org_elements_padded +
shard_indices.num_added_elements,
range_start + shard_indices.num_org_elements_padded +
shard_indices.num_added_elements_padded))
assert (range_start + shard_indices.num_org_elements_padded +
shard_indices.num_added_elements_padded == range_end)
ret = base_embeddings + added_embeddings + padding
assert len(ret) == self.num_embeddings_padded
return ret
def weight_loader(self, param: Parameter, loaded_weight: torch.Tensor):
output_dim = getattr(param, "output_dim", None)
packed_dim = getattr(param, "packed_dim", None)
# If parameter does not have output dim, then it should
# be copied onto all gpus (e.g. g_idx for act_order gptq).
if output_dim is None:
assert param.data.shape == loaded_weight.shape
param.data.copy_(loaded_weight)
return
# Shard indexes for loading the weight
start_idx = self.shard_indices.org_vocab_start_index
shard_size = self.shard_indices.org_vocab_end_index - start_idx
# If param packed on the same dim we are sharding on, then
# need to adjust offsets of loaded weight by pack_factor.
if packed_dim is not None and packed_dim == output_dim:
assert loaded_weight.shape[output_dim] == (self.org_vocab_size //
param.pack_factor)
start_idx = start_idx // param.pack_factor
shard_size = shard_size // param.pack_factor
else:
assert loaded_weight.shape[output_dim] == self.org_vocab_size
# Copy the data.
loaded_weight = loaded_weight.narrow(output_dim, start_idx, shard_size)
param[:loaded_weight.shape[0]].data.copy_(loaded_weight)
param[loaded_weight.shape[0]:].data.fill_(0)
def forward(self, input_):
if self.tp_size > 1:
# Build the mask.
masked_input, input_mask = get_masked_input_and_mask(
input_, self.shard_indices.org_vocab_start_index,
self.shard_indices.org_vocab_end_index,
self.shard_indices.num_org_vocab_padding,
self.shard_indices.added_vocab_start_index,
self.shard_indices.added_vocab_end_index)
else:
masked_input = input_
# Get the embeddings.
output_parallel = F.embedding(masked_input.long(), self.weight)
# Mask the output embedding.
if self.tp_size > 1:
output_parallel.masked_fill_(input_mask.unsqueeze(-1), 0)
# Reduce across all the model parallel GPUs.
output = tensor_model_parallel_all_reduce(output_parallel)
return output
def extra_repr(self) -> str:
s = f"num_embeddings={self.num_embeddings_per_partition}"
s += f", embedding_dim={self.embedding_dim}"
s += f", org_vocab_size={self.org_vocab_size}"
s += f', num_embeddings_padded={self.num_embeddings_padded}'
s += f', tp_size={self.tp_size}'
return s
class ParallelLMHead(VocabParallelEmbedding):
"""Parallelized LM head.
Output logits weight matrices used in the Sampler. The weight and bias
tensors are padded to make sure they are divisible by the number of
model parallel GPUs.
Args:
num_embeddings: vocabulary size.
embedding_dim: size of hidden state.
bias: whether to use bias.
params_dtype: type of the parameters.
org_num_embeddings: original vocabulary size (without LoRA).
padding_size: padding size for the vocabulary.
"""
def __init__(self,
num_embeddings: int,
embedding_dim: int,
bias: bool = False,
params_dtype: Optional[torch.dtype] = None,
org_num_embeddings: Optional[int] = None,
padding_size: int = DEFAULT_VOCAB_PADDING_SIZE,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = ""):
super().__init__(num_embeddings, embedding_dim, params_dtype,
org_num_embeddings, padding_size, quant_config,
prefix)
if bias:
self.bias = Parameter(
torch.empty(self.num_embeddings_per_partition,
dtype=params_dtype))
set_weight_attrs(self.bias, {
"output_dim": 0,
"weight_loader": self.weight_loader,
})
else:
self.register_parameter("bias", None)
def forward(self, input_):
del input_
raise RuntimeError("LMHead's weights should be used in the sampler.")