Alex Brooks 983a40a8bb
[Bugfix] Fix Positive Feature Layers in Llava Models (#13514)
Signed-off-by: Alex-Brooks <Alex.brooks@ibm.com>
2025-02-19 08:50:07 +00:00

414 lines
15 KiB
Python

# SPDX-License-Identifier: Apache-2.0
"""Minimal implementation of CLIPVisionModel intended to be only used
within a vision language model."""
from typing import Iterable, Optional, Set, Tuple, Union
import torch
import torch.nn as nn
from transformers import CLIPVisionConfig
from vllm.attention.layer import MultiHeadAttention
from vllm.distributed import divide, get_tensor_model_parallel_world_size
from vllm.model_executor.layers.activation import get_act_fn
from vllm.model_executor.layers.linear import (ColumnParallelLinear,
QKVParallelLinear,
RowParallelLinear)
from vllm.model_executor.layers.quantization import QuantizationConfig
from vllm.model_executor.model_loader.weight_utils import default_weight_loader
from vllm.model_executor.models.interfaces import SupportsQuant
from .vision import VisionEncoderInfo, resolve_visual_encoder_outputs
class CLIPEncoderInfo(VisionEncoderInfo[CLIPVisionConfig]):
def get_num_image_tokens(
self,
*,
image_width: int,
image_height: int,
) -> int:
return self.get_patch_grid_length()**2 + 1
def get_max_image_tokens(self) -> int:
return self.get_patch_grid_length()**2 + 1
def get_image_size(self) -> int:
return self.vision_config.image_size
def get_patch_size(self) -> int:
return self.vision_config.patch_size
def get_patch_grid_length(self) -> int:
image_size, patch_size = self.get_image_size(), self.get_patch_size()
assert image_size % patch_size == 0
return image_size // patch_size
# Adapted from https://github.com/huggingface/transformers/blob/v4.39.0/src/transformers/models/clip/modeling_clip.py#L164 # noqa
class CLIPVisionEmbeddings(nn.Module):
def __init__(self, config: CLIPVisionConfig):
super().__init__()
self.config = config
self.embed_dim = config.hidden_size
self.image_size = config.image_size
self.patch_size = config.patch_size
assert self.image_size % self.patch_size == 0
self.class_embedding = nn.Parameter(torch.randn(self.embed_dim))
self.patch_embedding = nn.Conv2d(
in_channels=config.num_channels,
out_channels=self.embed_dim,
kernel_size=self.patch_size,
stride=self.patch_size,
bias=False,
)
self.num_patches = (self.image_size // self.patch_size)**2
self.num_positions = self.num_patches + 1
self.position_embedding = nn.Embedding(self.num_positions,
self.embed_dim)
self.register_buffer("position_ids",
torch.arange(self.num_positions).expand((1, -1)),
persistent=False)
def forward(self, pixel_values: torch.Tensor) -> torch.Tensor:
batch_size = pixel_values.shape[0]
target_dtype = self.patch_embedding.weight.dtype
patch_embeds = self.patch_embedding(pixel_values.to(
dtype=target_dtype)) # shape = [*, width, grid, grid]
patch_embeds = patch_embeds.flatten(2).transpose(1, 2)
class_embeds = self.class_embedding.expand(batch_size, 1, -1)
embeddings = torch.cat([class_embeds, patch_embeds], dim=1)
embeddings = embeddings + self.position_embedding(self.position_ids)
return embeddings
class CLIPAttention(nn.Module):
"""Multi-headed attention from 'Attention Is All You Need' paper"""
def __init__(
self,
config: CLIPVisionConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
):
super().__init__()
self.config = config
self.embed_dim = config.hidden_size
self.num_heads = config.num_attention_heads
self.head_dim = self.embed_dim // self.num_heads
if self.head_dim * self.num_heads != self.embed_dim:
raise ValueError(
"embed_dim must be divisible by num_heads "
f"(got `embed_dim`: {self.embed_dim} and `num_heads`:"
f" {self.num_heads}).")
self.scale = self.head_dim**-0.5
self.dropout = config.attention_dropout
self.qkv_proj = QKVParallelLinear(
hidden_size=self.embed_dim,
head_size=self.head_dim,
total_num_heads=self.num_heads,
quant_config=quant_config,
prefix=f"{prefix}.qkv_proj",
)
self.out_proj = RowParallelLinear(
input_size=self.embed_dim,
output_size=self.embed_dim,
quant_config=quant_config,
prefix=f"{prefix}.out_proj",
)
self.tp_size = get_tensor_model_parallel_world_size()
self.num_heads_per_partition = divide(self.num_heads, self.tp_size)
self.attn = MultiHeadAttention(self.num_heads_per_partition,
self.head_dim, self.scale)
def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
return tensor.view(bsz, seq_len, self.num_heads,
self.head_dim).transpose(1, 2).contiguous()
def forward(
self,
hidden_states: torch.Tensor,
):
"""Input shape: Batch x Time x Channel"""
qkv_states, _ = self.qkv_proj(hidden_states)
query_states, key_states, value_states = qkv_states.chunk(3, dim=-1)
out = self.attn(query_states, key_states, value_states)
attn_output, _ = self.out_proj(out)
return attn_output, None
class CLIPMLP(nn.Module):
def __init__(
self,
config: CLIPVisionConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.config = config
self.activation_fn = get_act_fn(config.hidden_act)
self.fc1 = ColumnParallelLinear(config.hidden_size,
config.intermediate_size,
bias=True,
quant_config=quant_config,
prefix=f"{prefix}.fc1")
self.fc2 = RowParallelLinear(config.intermediate_size,
config.hidden_size,
bias=True,
quant_config=quant_config,
prefix=f"{prefix}.fc2")
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
hidden_states, _ = self.fc1(hidden_states)
hidden_states = self.activation_fn(hidden_states)
hidden_states, _ = self.fc2(hidden_states)
return hidden_states
class CLIPEncoderLayer(nn.Module):
def __init__(
self,
config: CLIPVisionConfig,
quant_config: Optional[QuantizationConfig] = None,
prefix: str = "",
) -> None:
super().__init__()
self.self_attn = CLIPAttention(
config,
quant_config=quant_config,
prefix=f"{prefix}.self_attn",
)
self.layer_norm1 = nn.LayerNorm(config.hidden_size,
eps=config.layer_norm_eps)
self.mlp = CLIPMLP(config,
quant_config=quant_config,
prefix=f"{prefix}.mlp")
self.layer_norm2 = nn.LayerNorm(config.hidden_size,
eps=config.layer_norm_eps)
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
residual = hidden_states
hidden_states = self.layer_norm1(hidden_states)
hidden_states, _ = self.self_attn(hidden_states=hidden_states)
hidden_states = residual + hidden_states
residual = hidden_states
hidden_states = self.layer_norm2(hidden_states)
hidden_states = self.mlp(hidden_states)
hidden_states = residual + hidden_states
return hidden_states
class CLIPEncoder(nn.Module):
"""
Transformer encoder consisting of `config.num_hidden_layers` self
attention layers. Each layer is a [`CLIPEncoderLayer`].
Args:
config: CLIPConfig
"""
def __init__(
self,
config: CLIPVisionConfig,
quant_config: Optional[QuantizationConfig] = None,
num_hidden_layers_override: Optional[int] = None,
prefix: str = "",
) -> None:
super().__init__()
self.config = config
if num_hidden_layers_override is None:
num_hidden_layers = config.num_hidden_layers
else:
num_hidden_layers = num_hidden_layers_override
self.layers = nn.ModuleList([
CLIPEncoderLayer(config=config,
quant_config=quant_config,
prefix=f"{prefix}.layers.{layer_idx}")
for layer_idx in range(num_hidden_layers)
])
def forward(
self, inputs_embeds: torch.Tensor, return_all_hidden_states: bool
) -> Union[torch.Tensor, list[torch.Tensor]]:
hidden_states_pool = [inputs_embeds]
hidden_states = inputs_embeds
for encoder_layer in self.layers:
hidden_states = encoder_layer(hidden_states)
if return_all_hidden_states:
hidden_states_pool.append(hidden_states)
# If we have multiple feature sample layers, we return all hidden
# states in order and grab the ones we need by index.
if return_all_hidden_states:
return hidden_states_pool
return hidden_states
class CLIPVisionTransformer(nn.Module):
def __init__(
self,
config: CLIPVisionConfig,
quant_config: Optional[QuantizationConfig] = None,
*,
num_hidden_layers_override: Optional[int] = None,
require_post_norm: Optional[bool] = None,
prefix: str = "",
) -> None:
super().__init__()
self.config = config
embed_dim = config.hidden_size
self.embeddings = CLIPVisionEmbeddings(config)
# NOTE: This typo of "layrnorm" is not fixed on purpose to match
# the original transformers code and name of the model weights.
self.pre_layrnorm = nn.LayerNorm(embed_dim, eps=config.layer_norm_eps)
self.encoder = CLIPEncoder(
config=config,
quant_config=quant_config,
num_hidden_layers_override=num_hidden_layers_override,
prefix=f"{prefix}.encoder",
)
num_hidden_layers = config.num_hidden_layers
if len(self.encoder.layers) > config.num_hidden_layers:
raise ValueError(
f"The original encoder only has {num_hidden_layers} "
f"layers, but you requested {len(self.encoder.layers)} layers."
)
# If possible, skip post_layernorm to conserve memory
if require_post_norm is None:
require_post_norm = len(self.encoder.layers) == num_hidden_layers
if require_post_norm:
self.post_layernorm = nn.LayerNorm(embed_dim,
eps=config.layer_norm_eps)
else:
self.post_layernorm = None
def forward(
self,
pixel_values: torch.Tensor,
feature_sample_layers: Optional[list[int]] = None,
) -> torch.Tensor:
hidden_states = self.embeddings(pixel_values)
hidden_states = self.pre_layrnorm(hidden_states)
return_all_hidden_states = feature_sample_layers is not None
# Produces either the last layer output or all of the hidden states,
# depending on if we have feature_sample_layers or not
encoder_outputs = self.encoder(
inputs_embeds=hidden_states,
return_all_hidden_states=return_all_hidden_states)
# Handle post-norm (if applicable) and stacks feature layers if needed
encoder_outputs = resolve_visual_encoder_outputs(
encoder_outputs, feature_sample_layers, self.post_layernorm,
self.config.num_hidden_layers)
return encoder_outputs
class CLIPVisionModel(nn.Module, SupportsQuant):
config_class = CLIPVisionConfig
main_input_name = "pixel_values"
packed_modules_mapping = {"qkv_proj": ["q_proj", "k_proj", "v_proj"]}
def __init__(
self,
config: CLIPVisionConfig,
quant_config: Optional[QuantizationConfig] = None,
*,
num_hidden_layers_override: Optional[int] = None,
require_post_norm: Optional[bool] = None,
prefix: str = "",
) -> None:
super().__init__()
self.vision_model = CLIPVisionTransformer(
config=config,
quant_config=quant_config,
num_hidden_layers_override=num_hidden_layers_override,
require_post_norm=require_post_norm,
prefix=f"{prefix}.vision_model")
def forward(
self,
pixel_values: torch.Tensor,
feature_sample_layers: Optional[list[int]] = None,
) -> torch.Tensor:
return self.vision_model(pixel_values, feature_sample_layers)
@property
def device(self):
return next(self.parameters()).device
# (TODO) Add prefix argument for filtering out weights to be loaded
# ref: https://github.com/vllm-project/vllm/pull/7186#discussion_r1734163986
def load_weights(self, weights: Iterable[Tuple[str,
torch.Tensor]]) -> Set[str]:
stacked_params_mapping = [
# (param_name, shard_name, shard_id)
("qkv_proj", "q_proj", "q"),
("qkv_proj", "k_proj", "k"),
("qkv_proj", "v_proj", "v"),
]
params_dict = dict(self.named_parameters())
loaded_params: Set[str] = set()
layer_count = len(self.vision_model.encoder.layers)
for name, loaded_weight in weights:
# post_layernorm is not needed in CLIPVisionModel
if (name.startswith("vision_model.post_layernorm")
and self.vision_model.post_layernorm is None):
continue
# omit layers when num_hidden_layers_override is set
if name.startswith("vision_model.encoder.layers"):
layer_idx = int(name.split(".")[3])
if layer_idx >= layer_count:
continue
for (param_name, weight_name, shard_id) in stacked_params_mapping:
if weight_name not in name:
continue
name = name.replace(weight_name, param_name)
param = params_dict[name]
weight_loader = param.weight_loader
weight_loader(param, loaded_weight, shard_id)
break
else:
param = params_dict[name]
weight_loader = getattr(param, "weight_loader",
default_weight_loader)
weight_loader(param, loaded_weight)
loaded_params.add(name)
return loaded_params