Kyle Sayers 36d1ccb286
[Quant] BartModel SupportsQuant (#14699)
Signed-off-by: Kyle Sayers <kylesayrs@gmail.com>
2025-03-13 04:55:59 +00:00

947 lines
33 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# Derived from BART implementation posted on HuggingFace; license below:
#
# coding=utf-8
# Copyright 2021 The Fairseq Authors and The HuggingFace Inc. team.
# 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.
"""PyTorch BART model."""
import math
from typing import Iterable, Optional, Tuple
import torch
from torch import nn
from transformers import BartConfig
from transformers.utils import logging
from vllm.attention import Attention, AttentionType
from vllm.config import CacheConfig, LoRAConfig, VllmConfig
from vllm.distributed import get_tensor_model_parallel_world_size
from vllm.model_executor.layers.activation import get_act_fn
from vllm.model_executor.layers.linear import (ColumnParallelLinear,
QKVCrossParallelLinear,
QKVParallelLinear,
RowParallelLinear)
from vllm.model_executor.layers.logits_processor import LogitsProcessor
from vllm.model_executor.layers.quantization.base_config import (
QuantizationConfig)
from vllm.model_executor.layers.sampler import SamplerOutput, get_sampler
from vllm.model_executor.layers.vocab_parallel_embedding import (
ParallelLMHead, VocabParallelEmbedding)
from vllm.model_executor.model_loader.weight_utils import default_weight_loader
from vllm.model_executor.sampling_metadata import SamplingMetadata
from vllm.sequence import IntermediateTensors
from .interfaces import SupportsQuant, SupportsV0Only
from .utils import maybe_prefix
logger = logging.get_logger(__name__)
def get_bsz_seq_len(input_ids):
shp = input_ids.shape
ndim = len(shp)
if ndim == 1:
return 1, input_ids.numel()
else:
return shp[:2]
class BartLearnedPositionalEmbedding(VocabParallelEmbedding):
"""
This module learns positional embeddings up to a fixed maximum size.
"""
def __init__(self, num_embeddings: int, embedding_dim: int):
# Bart is set up so that if padding_idx is
# specified then offset the embedding ids by 2
# and adjust num_embeddings appropriately.
# Other models don't have this hack
self.offset = 2
super().__init__(num_embeddings + self.offset, embedding_dim)
def forward(
self,
positions: torch.Tensor,
) -> torch.Tensor:
"""`input_ids' shape is expected to be [bsz x seqlen]."""
return super().forward(positions + self.offset)
class BartScaledWordEmbedding(VocabParallelEmbedding):
"""
This module overrides VocabParallelEmbedding's
forward by multiplying with embeddings scale.
"""
def __init__(self,
num_embeddings: int,
embedding_dim: int,
embed_scale: float = 1.0):
super().__init__(num_embeddings, embedding_dim)
self.embed_scale = embed_scale
def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
return super().forward(input_ids) * self.embed_scale
class BartParallelLMHead(ParallelLMHead):
"""
This module overrides ParallelLMHead's
forward by dividing by embeddings scale,
yielding effectively the inverse of
BartScaledWordEmbedding
"""
def __init__(self,
num_embeddings: int,
embedding_dim: int,
embed_scale: float = 1.0):
super().__init__(num_embeddings, embedding_dim)
self.embed_scale = embed_scale
def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
return super().forward(input_ids) / self.embed_scale
class BartEncoderAttention(nn.Module):
def __init__(
self,
embed_dim: int,
num_heads: int,
bias: bool = True,
config: Optional[BartConfig] = None,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.d_model = config.d_model
self.embed_dim = embed_dim
self.total_num_heads = num_heads
self.total_num_kv_heads = self.total_num_heads
self.head_dim = embed_dim // num_heads
self.config = config
if (self.head_dim * num_heads) != self.embed_dim:
raise ValueError(f"embed_dim must be divisible by num_heads "
f"(got `embed_dim`: {self.embed_dim}"
f" and `num_heads`: {num_heads}).")
self.scaling = self.head_dim**-0.5
self.qkv_proj = QKVParallelLinear(
self.d_model,
self.d_model // self.total_num_heads,
self.total_num_heads,
self.total_num_kv_heads,
bias=bias,
quant_config=quant_config,
)
self.out_proj = RowParallelLinear(
embed_dim,
embed_dim,
bias=bias,
quant_config=quant_config,
)
tp_world_size = get_tensor_model_parallel_world_size()
assert self.total_num_heads % tp_world_size == 0
self.num_heads = self.total_num_heads // tp_world_size
if self.total_num_kv_heads >= tp_world_size:
# Number of KV heads is greater than TP size, so we partition
# the KV heads across multiple tensor parallel GPUs.
assert self.total_num_kv_heads % tp_world_size == 0
else:
# Number of KV heads is less than TP size, so we replicate
# the KV heads across multiple tensor parallel GPUs.
assert tp_world_size % self.total_num_kv_heads == 0
self.num_kv_heads = self.num_heads
self.q_size = self.num_heads * self.head_dim
self.kv_size = self.num_kv_heads * self.head_dim
self.attn = Attention(self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_kv_heads,
cache_config=cache_config,
quant_config=quant_config,
prefix=f"{prefix}.attn",
attn_type=AttentionType.ENCODER)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
"""Input shape: Batch x Time x Channel"""
qkv, _ = self.qkv_proj(hidden_states)
q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1)
attn_output = self.attn(q, k, v)
output, _ = self.out_proj(attn_output)
return output
class BartDecoderSelfAttention(nn.Module):
def __init__(
self,
embed_dim: int,
num_heads: int,
bias: bool = True,
config: Optional[BartConfig] = None,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.d_model = config.d_model
self.embed_dim = embed_dim
self.total_num_heads = num_heads
self.total_num_kv_heads = self.total_num_heads
self.head_dim = embed_dim // num_heads
self.config = config
if (self.head_dim * num_heads) != self.embed_dim:
raise ValueError(f"embed_dim must be divisible by num_heads "
f"(got `embed_dim`: {self.embed_dim}"
f" and `num_heads`: {num_heads}).")
self.scaling = self.head_dim**-0.5
self.qkv_proj = QKVParallelLinear(
self.d_model,
self.d_model // self.total_num_heads,
self.total_num_heads,
self.total_num_kv_heads,
bias=bias,
quant_config=quant_config,
)
self.out_proj = RowParallelLinear(
embed_dim,
embed_dim,
bias=bias,
quant_config=quant_config,
)
tp_world_size = get_tensor_model_parallel_world_size()
assert self.total_num_heads % tp_world_size == 0
self.num_heads = self.total_num_heads // tp_world_size
if self.total_num_kv_heads >= tp_world_size:
# Number of KV heads is greater than TP size, so we partition
# the KV heads across multiple tensor parallel GPUs.
assert self.total_num_kv_heads % tp_world_size == 0
else:
# Number of KV heads is less than TP size, so we replicate
# the KV heads across multiple tensor parallel GPUs.
assert tp_world_size % self.total_num_kv_heads == 0
self.num_kv_heads = self.num_heads
self.q_size = self.num_heads * self.head_dim
self.kv_size = self.num_kv_heads * self.head_dim
self.attn = Attention(self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_kv_heads,
cache_config=cache_config,
quant_config=quant_config,
prefix=f"{prefix}.attn",
attn_type=AttentionType.DECODER)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
"""Input shape: Batch x Time x Channel"""
qkv, _ = self.qkv_proj(hidden_states)
q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1)
attn_output = self.attn(q, k, v)
output, _ = self.out_proj(attn_output)
return output
class BartCrossAttention(nn.Module):
def __init__(
self,
embed_dim: int,
num_heads: int,
bias: bool = True,
config: Optional[BartConfig] = None,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.d_model = config.d_model
self.embed_dim = embed_dim
self.total_num_heads = num_heads
self.total_num_kv_heads = self.total_num_heads
self.head_dim = embed_dim // num_heads
self.config = config
if (self.head_dim * num_heads) != self.embed_dim:
raise ValueError(f"embed_dim must be divisible by num_heads "
f"(got `embed_dim`: {self.embed_dim}"
f" and `num_heads`: {num_heads}).")
self.scaling = self.head_dim**-0.5
# TP sharding sizes is accounted for within "*Parallel" layers.
self.qkv_proj = QKVCrossParallelLinear(self.d_model,
self.d_model //
self.total_num_heads,
self.total_num_heads,
self.total_num_kv_heads,
bias,
quant_config=quant_config)
self.out_proj = RowParallelLinear(
embed_dim,
embed_dim,
bias=bias,
quant_config=quant_config,
)
tp_world_size = get_tensor_model_parallel_world_size()
assert self.total_num_heads % tp_world_size == 0
self.num_heads = self.total_num_heads // tp_world_size
if self.total_num_kv_heads >= tp_world_size:
# Number of KV heads is greater than TP size, so we partition
# the KV heads across multiple tensor parallel GPUs.
assert self.total_num_kv_heads % tp_world_size == 0
else:
# Number of KV heads is less than TP size, so we replicate
# the KV heads across multiple tensor parallel GPUs.
assert tp_world_size % self.total_num_kv_heads == 0
self.num_kv_heads = self.num_heads # No GQA in bart
self.attn = Attention(self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_kv_heads,
cache_config=cache_config,
quant_config=quant_config,
prefix=f"{prefix}.attn",
attn_type=AttentionType.ENCODER_DECODER)
def forward(
self,
decoder_hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor] = None,
) -> torch.Tensor:
"""Input shape: Batch x Time x Channel"""
q, k, v = self.qkv_proj(decoder_hidden_states, encoder_hidden_states)
attn_output = self.attn(q, k, v)
output, _ = self.out_proj(attn_output)
return output
class BartEncoderLayer(nn.Module):
def __init__(
self,
config: BartConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.embed_dim = config.d_model
self.self_attn = BartEncoderAttention(
embed_dim=self.embed_dim,
num_heads=config.encoder_attention_heads,
config=config,
cache_config=cache_config,
quant_config=quant_config,
prefix=f"{prefix}.self_attn",
)
self.self_attn_layer_norm = nn.LayerNorm(self.embed_dim)
self.activation_fn = get_act_fn(config.activation_function)
ffn_hidden_size = self.embed_dim
ffn_intermediate_size = config.encoder_ffn_dim
ffn_has_bias = True
self.fc1 = ColumnParallelLinear(
ffn_hidden_size,
ffn_intermediate_size,
bias=ffn_has_bias,
quant_config=quant_config,
)
self.act = get_act_fn("gelu")
self.fc2 = RowParallelLinear(
ffn_intermediate_size,
ffn_hidden_size,
bias=ffn_has_bias,
quant_config=quant_config,
)
self.final_layer_norm = nn.LayerNorm(self.embed_dim)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
r"""
Args:
hidden_states
torch.Tensor of *encoder* input embeddings.
Returns:
Encoder layer output torch.Tensor
"""
residual = hidden_states
hidden_states = self.self_attn(hidden_states=hidden_states)
hidden_states = residual + hidden_states
hidden_states = self.self_attn_layer_norm(hidden_states)
residual = hidden_states
fc1_out, _ = self.fc1(hidden_states)
hidden_states = self.activation_fn(fc1_out)
hidden_states, _ = self.fc2(hidden_states)
hidden_states = residual + hidden_states
hidden_states = self.final_layer_norm(hidden_states)
if hidden_states.dtype == torch.float16 and (
torch.isinf(hidden_states).any()
or torch.isnan(hidden_states).any()):
clamp_value = torch.finfo(hidden_states.dtype).max - 1000
hidden_states = torch.clamp(hidden_states,
min=-clamp_value,
max=clamp_value)
return hidden_states
class BartDecoderLayer(nn.Module):
def __init__(
self,
config: BartConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.embed_dim = config.d_model
self.self_attn = BartDecoderSelfAttention(
embed_dim=self.embed_dim,
num_heads=config.decoder_attention_heads,
config=config,
cache_config=cache_config,
quant_config=quant_config,
prefix=f"{prefix}.self_attn",
)
self.activation_fn = get_act_fn(config.activation_function)
self.self_attn_layer_norm = nn.LayerNorm(self.embed_dim)
'''
afeldman-nm: personally I would call this "cross-attention",
however I left the name as "encoder_attn" to maintain consistency
with the name of the pretrained weights.
'''
self.encoder_attn = BartCrossAttention(
self.embed_dim,
config.decoder_attention_heads,
config=config,
prefix=f"{prefix}.encoder_attn",
)
self.encoder_attn_layer_norm = nn.LayerNorm(self.embed_dim)
ffn_hidden_size = self.embed_dim
ffn_intermediate_size = config.encoder_ffn_dim
ffn_has_bias = True
self.fc1 = ColumnParallelLinear(
ffn_hidden_size,
ffn_intermediate_size,
bias=ffn_has_bias,
quant_config=quant_config,
)
self.fc2 = RowParallelLinear(
ffn_intermediate_size,
ffn_hidden_size,
bias=ffn_has_bias,
quant_config=quant_config,
)
self.final_layer_norm = nn.LayerNorm(self.embed_dim)
def forward(
self,
decoder_hidden_states: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor] = None,
) -> torch.Tensor:
r"""
Args:
decoder_hidden_states
torch.Tensor of *decoder* input embeddings.
encoder_hidden_states
torch.Tensor of *encoder* input embeddings.
Returns:
Decoder layer output torch.Tensor
"""
residual = decoder_hidden_states
# Self Attention
hidden_states = self.self_attn(hidden_states=decoder_hidden_states)
hidden_states = residual + hidden_states
hidden_states = self.self_attn_layer_norm(hidden_states)
# Cross-Attention Block
residual = hidden_states
hidden_states = self.encoder_attn(
decoder_hidden_states=hidden_states,
encoder_hidden_states=encoder_hidden_states,
)
hidden_states = residual + hidden_states
hidden_states = self.encoder_attn_layer_norm(hidden_states)
# Fully Connected
residual = hidden_states
fc1_out, _ = self.fc1(hidden_states)
hidden_states = self.activation_fn(fc1_out)
hidden_states, _ = self.fc2(hidden_states)
hidden_states = residual + hidden_states
hidden_states = self.final_layer_norm(hidden_states)
return hidden_states
class BartEncoder(nn.Module):
"""
Transformer encoder consisting of *config.encoder_layers*
self attention layers. Each layer is a [`BartEncoderLayer`].
Args:
config: BartConfig
embed_tokens (nn.Embedding): output embedding
"""
def __init__(self,
config: BartConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
lora_config: Optional[LoRAConfig] = None,
embed_tokens: Optional[nn.Embedding] = None,
prefix: str = ""):
super().__init__()
self.cache_config = cache_config
self.quant_config = quant_config
self.lora_config = lora_config
embed_dim = config.d_model
self.max_source_positions = config.max_position_embeddings
embed_scale = math.sqrt(embed_dim) if config.scale_embedding else 1.0
self.embed_tokens = BartScaledWordEmbedding(config.vocab_size,
embed_dim,
embed_scale=embed_scale)
if embed_tokens is not None:
self.embed_tokens.weight = embed_tokens.weight
self.embed_positions = BartLearnedPositionalEmbedding(
config.max_position_embeddings,
embed_dim,
)
self.layers = nn.ModuleList([
BartEncoderLayer(config,
cache_config,
quant_config,
prefix=f"{prefix}.layers.{layer_idx}")
for layer_idx in range(config.encoder_layers)
])
self.layernorm_embedding = nn.LayerNorm(embed_dim)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
inputs_embeds: Optional[torch.Tensor] = None,
) -> torch.Tensor:
r"""
Args:
input_ids
Indices of *encoder* input sequence tokens in the vocabulary.
Padding will be ignored by default should you
provide it.
positions
Positions of *encoder* input sequence tokens.
Returns:
Decoder output torch.Tensor
"""
# retrieve input_ids and inputs_embeds
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(input_ids)
embed_pos = self.embed_positions(positions)
embed_pos = embed_pos.to(inputs_embeds.device)
hidden_states = inputs_embeds + embed_pos
hidden_states = self.layernorm_embedding(hidden_states)
for encoder_layer in self.layers:
hidden_states = encoder_layer(hidden_states=hidden_states)
return hidden_states
class BartDecoder(nn.Module):
"""
Transformer decoder consisting of *config.decoder_layers* layers.
Each layer is a [`BartDecoderLayer`]
Args:
config: BartConfig
embed_tokens (nn.Embedding): output embedding
"""
def __init__(
self,
config: BartConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
lora_config: Optional[LoRAConfig] = None,
embed_tokens: Optional[nn.Embedding] = None,
prefix: str = "",
):
super().__init__()
self.cache_config = cache_config
self.quant_config = quant_config
self.lora_config = lora_config
self.max_target_positions = config.max_position_embeddings
embed_scale = math.sqrt(
config.d_model) if config.scale_embedding else 1.0
self.embed_tokens = BartScaledWordEmbedding(config.vocab_size,
config.d_model,
embed_scale=embed_scale)
if embed_tokens is not None:
self.embed_tokens.weight = embed_tokens.weight
self.embed_positions = BartLearnedPositionalEmbedding(
config.max_position_embeddings,
config.d_model,
)
self.layers = nn.ModuleList(
[BartDecoderLayer(config,cache_config,quant_config,
prefix=f"{prefix}.layers.{layer_idx}") \
for layer_idx in range(config.decoder_layers)])
self.layernorm_embedding = nn.LayerNorm(config.d_model)
def forward(
self,
decoder_input_ids: torch.Tensor,
decoder_positions: torch.Tensor,
encoder_hidden_states: Optional[torch.Tensor],
inputs_embeds: Optional[torch.Tensor] = None,
) -> torch.Tensor:
r"""
Args:
decoder_input_ids
Indices of *decoder* input sequence tokens in the vocabulary.
Padding will be ignored by default should you
provide it.
decoder_positions
Positions of *decoder* input sequence tokens.
encoder_hidden_states:
Tensor of encoder output embeddings
Returns:
Decoder output torch.Tensor
"""
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(decoder_input_ids)
else:
decoder_positions = inputs_embeds[:, -1]
# embed positions
embed_pos = self.embed_positions(decoder_positions)
embed_pos = embed_pos.to(inputs_embeds.device)
hidden_states = inputs_embeds + embed_pos
hidden_states = self.layernorm_embedding(hidden_states)
# decoder layers
for decoder_layer in self.layers:
hidden_states = decoder_layer(
decoder_hidden_states=hidden_states,
encoder_hidden_states=encoder_hidden_states,
)
return hidden_states
class BartModel(nn.Module, SupportsQuant):
_tied_weights_keys = [
"encoder.embed_tokens.weight", "decoder.embed_tokens.weight"
]
def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
super().__init__()
config = vllm_config.model_config.hf_config
cache_config = vllm_config.cache_config
quant_config = vllm_config.quant_config
lora_config = vllm_config.lora_config
self.config = config
lora_vocab = (lora_config.lora_extra_vocab_size *
(lora_config.max_loras or 1)) if lora_config else 0
self.vocab_size = config.vocab_size + lora_vocab
self.org_vocab_size = config.vocab_size
self.encoder = BartEncoder(config,
cache_config,
quant_config=quant_config,
prefix=f"{prefix}.encoder")
self.decoder = BartDecoder(config,
cache_config,
quant_config=quant_config,
prefix=f"{prefix}.decoder")
def forward(self, input_ids: torch.Tensor, positions: torch.Tensor,
encoder_input_ids: torch.Tensor,
encoder_positions: torch.Tensor) -> torch.Tensor:
r"""
Args:
input_ids
Indices of *decoder* input sequence tokens in the vocabulary.
Padding will be ignored by default should you
provide it.
positions
Positions of *decoder* input sequence tokens.
encoder_input_ids
Indices of *encoder* input sequence tokens in the vocabulary.
encoder_positions:
Positions of *encoder* input sequence tokens.
Returns:
Model output torch.Tensor
"""
encoder_hidden_states = None
if encoder_input_ids.numel() > 0:
# Run encoder attention if a non-zero number of encoder tokens
# are provided as input
encoder_hidden_states = self.encoder(input_ids=encoder_input_ids,
positions=encoder_positions)
# decoder outputs consists of
# (dec_features, past_key_value, dec_hidden, dec_attn)
decoder_outputs = self.decoder(
decoder_input_ids=input_ids,
decoder_positions=positions,
encoder_hidden_states=encoder_hidden_states)
return decoder_outputs
class BartForConditionalGeneration(nn.Module, SupportsV0Only, SupportsQuant):
packed_modules_mapping = {"qkv_proj": ["q_proj", "k_proj", "v_proj"]}
base_model_prefix = "model"
def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
super().__init__()
config = vllm_config.model_config.hf_config
lora_config = vllm_config.lora_config
# currently all existing BART models have `tie_word_embeddings` enabled
assert config.tie_word_embeddings
self.config = config
self.model = BartModel(vllm_config=vllm_config,
prefix=maybe_prefix(prefix, "model"))
self.unpadded_vocab_size = config.vocab_size
if lora_config:
self.unpadded_vocab_size += lora_config.lora_extra_vocab_size
embed_scale = math.sqrt(
config.d_model) if config.scale_embedding else 1.0
self.lm_head = BartParallelLMHead(config.vocab_size,
config.d_model,
embed_scale=embed_scale)
self.logits_processor = LogitsProcessor(self.unpadded_vocab_size,
config.vocab_size)
self.sampler = get_sampler()
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
intermediate_tensors: Optional[IntermediateTensors] = None,
*,
encoder_input_ids: torch.Tensor,
encoder_positions: torch.Tensor,
**kwargs,
) -> torch.Tensor:
r"""
Args:
input_ids
torch.Tensor of *decoder* input token ids.
positions
torch.Tensor of *decoder* position indices.
encoder_input_ids
torch.Tensor of *encoder* input token ids.
encoder_positions
torch.Tensor of *encoder* position indices
Returns:
Output torch.Tensor
"""
return self.model(input_ids, positions, encoder_input_ids,
encoder_positions)
def compute_logits(
self,
hidden_states: torch.Tensor,
sampling_metadata: SamplingMetadata,
) -> Optional[torch.Tensor]:
logits = self.logits_processor(self.lm_head, hidden_states,
sampling_metadata)
return logits
def sample(
self,
logits: Optional[torch.Tensor],
sampling_metadata: SamplingMetadata,
) -> Optional[SamplerOutput]:
next_tokens = self.sampler(logits, sampling_metadata)
return next_tokens
stacked_params_mapping = {
"q_proj": {
"param_name": "qkv_proj",
"shard_id": "q",
},
"k_proj": {
"param_name": "qkv_proj",
"shard_id": "k",
},
"v_proj": {
"param_name": "qkv_proj",
"shard_id": "v",
},
}
params_mapping = {
"beta": "bias",
"gamma": "weight",
"LayerNorm": "layernorm",
}
def _rename_key(self, key: str):
prefix = f"{self.base_model_prefix}."
key = key[len(prefix):] if key.startswith(prefix) else key
for src, dst in self.params_mapping.items():
key = key.replace(src, dst)
return key
def _rename_stacked_param(
self,
name: str,
) -> Tuple[str, Optional[str]]:
for key, mapping in self.stacked_params_mapping.items():
if key in name:
name = name.replace(key, mapping["param_name"])
return name, mapping["shard_id"]
return name, None
def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
model_params_dict = dict(self.model.named_parameters())
top_params_dict = dict(self.named_parameters())
weights_tuple_list = list(weights)
shared_embedding_weight = None
shared_embedding_shard_id = None
for name, loaded_weight in weights_tuple_list:
name = self._rename_key(name)
name, shard_id = self._rename_stacked_param(name)
if ('shared.weight' in name
or 'encoder.embed_tokens.weight' in name
or 'decoder.embed_tokens.weight' in name
or 'lm_head.weight' in name):
assert shared_embedding_weight is None, (
"Conflicting embedding weights.")
shared_embedding_weight = loaded_weight
shared_embedding_shard_id = shard_id
else:
# Skip the specific downstream task weight.
if name.startswith('cls.'):
continue
# use Pooler instead.
if name.startswith('pooler.'):
continue
# Skip loading extra bias for GPTQ models.
if name.endswith(".bias") and name not in model_params_dict:
continue
param = model_params_dict[name]
weight_loader = getattr(param, "weight_loader",
default_weight_loader)
if shard_id:
weight_loader(param, loaded_weight, shard_id)
else:
weight_loader(param, loaded_weight)
# Assign shared weight values
encoder_in_param = model_params_dict['encoder.embed_tokens.weight']
encoder_in_weight_loader = getattr(encoder_in_param, "weight_loader",
default_weight_loader)
decoder_in_param = model_params_dict['decoder.embed_tokens.weight']
decoder_in_weight_loader = getattr(decoder_in_param, "weight_loader",
default_weight_loader)
lm_head_in_param = top_params_dict['lm_head.weight']
lm_head_in_weight_loader = getattr(lm_head_in_param, "weight_loader",
default_weight_loader)
assert shared_embedding_weight is not None
if shared_embedding_shard_id:
encoder_in_weight_loader(encoder_in_param, shared_embedding_weight,
shared_embedding_shard_id)
decoder_in_weight_loader(decoder_in_param, shared_embedding_weight,
shared_embedding_shard_id)
lm_head_in_weight_loader(lm_head_in_param, shared_embedding_weight,
shared_embedding_shard_id)
else:
encoder_in_weight_loader(encoder_in_param, shared_embedding_weight)
decoder_in_weight_loader(decoder_in_param, shared_embedding_weight)
lm_head_in_weight_loader(lm_head_in_param, shared_embedding_weight)