Harry Mellor 97d1c99302
Rename clashing method names for vLLM model protocol (#27583)
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
2025-11-12 19:14:33 -08:00

280 lines
10 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
# Copyright 2025 The Baidu team.
# Copyright 2023 The vLLM team.
# Copyright 2022 EleutherAI and the HuggingFace Inc. team. All rights reserved.
#
# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
# and OPT implementations in this library. It has been modified from its
# original forms to accommodate minor architectural differences compared
# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
#
# 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.
"""Inference-only Ernie-MTP model."""
from collections.abc import Iterable
import torch
import torch.nn as nn
from transformers import PretrainedConfig
from vllm.config import VllmConfig
from vllm.model_executor.layers.layernorm import RMSNorm
from vllm.model_executor.layers.logits_processor import LogitsProcessor
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.sequence import IntermediateTensors
from .interfaces import SupportsPP
from .llama import LlamaDecoderLayer
from .utils import is_pp_missing_parameter, maybe_prefix
class ErnieMultiTokenPredictorLayer(nn.Module):
def __init__(
self,
vllm_config: VllmConfig,
prefix: str,
) -> None:
super().__init__()
config = vllm_config.model_config.hf_config
self.mtp_emb_norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.mtp_hidden_norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.mtp_linear_proj = nn.Linear(
config.hidden_size * 2, config.hidden_size, bias=False
)
self.mtp_block = LlamaDecoderLayer(vllm_config, prefix)
def forward(
self,
inputs_embeds: torch.Tensor,
positions: torch.Tensor,
previous_hidden_states: torch.Tensor,
spec_step_index: int = 0,
) -> torch.Tensor:
assert inputs_embeds is not None
# masking inputs at position 0, as not needed by MTP
inputs_embeds[positions == 0] = 0
inputs_embeds = self.mtp_emb_norm(inputs_embeds)
previous_hidden_states = self.mtp_hidden_norm(previous_hidden_states)
hidden_states = self.mtp_linear_proj(
torch.cat([inputs_embeds, previous_hidden_states], dim=-1)
)
hidden_states, residual = self.mtp_block(
positions=positions, hidden_states=hidden_states, residual=None
)
hidden_states = residual + hidden_states
return hidden_states
class ErnieMultiTokenPredictor(nn.Module):
def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
super().__init__()
config = vllm_config.model_config.hf_config
self.mtp_start_layer_idx = config.num_hidden_layers
self.num_mtp_layers = config.num_nextn_predict_layers
# to map the exact layer index from weights
self.layers = torch.nn.ModuleDict(
{
str(idx): ErnieMultiTokenPredictorLayer(
vllm_config,
f"{prefix}.layers.{idx}",
)
for idx in range(
self.mtp_start_layer_idx,
self.mtp_start_layer_idx + self.num_mtp_layers,
)
}
)
self.embed_tokens = VocabParallelEmbedding(
config.vocab_size,
config.hidden_size,
)
self.logits_processor = LogitsProcessor(config.vocab_size)
def embed_input_ids(self, input_ids: torch.Tensor) -> torch.Tensor:
return self.embed_tokens(input_ids)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
previous_hidden_states: torch.Tensor,
inputs_embeds: torch.Tensor | None = None,
spec_step_idx: int = 0,
) -> torch.Tensor:
if inputs_embeds is None:
inputs_embeds = self.embed_tokens(input_ids)
return self.layers[str(self.mtp_start_layer_idx + spec_step_idx)](
inputs_embeds,
positions,
previous_hidden_states,
spec_step_idx,
)
def compute_logits(
self,
hidden_states: torch.Tensor,
lm_head: ParallelLMHead,
spec_step_idx: int = 0,
) -> torch.Tensor:
self.layers[str(self.mtp_start_layer_idx + spec_step_idx)]
logits = self.logits_processor(lm_head, hidden_states)
return logits
class ErnieMTP(nn.Module, SupportsPP):
def __init__(self, *, vllm_config: VllmConfig, prefix: str = ""):
super().__init__()
self.config = vllm_config.model_config.hf_config
self.model = ErnieMultiTokenPredictor(
vllm_config=vllm_config, prefix=maybe_prefix(prefix, "model")
)
self.lm_head = ParallelLMHead(
self.config.vocab_size,
self.config.hidden_size,
prefix=maybe_prefix(prefix, "lm_head"),
)
if self.config.tie_word_embeddings:
self.lm_head.weight = self.model.embed_tokens.weight
def embed_input_ids(self, input_ids: torch.Tensor) -> torch.Tensor:
return self.model.embed_input_ids(input_ids)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
hidden_states: torch.Tensor,
intermediate_tensors: IntermediateTensors | None = None,
inputs_embeds: torch.Tensor | None = None,
spec_step_idx: int = 0,
) -> torch.Tensor:
assert spec_step_idx == 0, "ernie_mtp only support predict one token"
hidden_states = self.model(
input_ids, positions, hidden_states, inputs_embeds, spec_step_idx
)
return hidden_states
def compute_logits(
self,
hidden_states: torch.Tensor,
spec_step_idx: int = 0,
) -> torch.Tensor | None:
return self.model.compute_logits(hidden_states, self.lm_head, spec_step_idx)
def load_weights(self, weights: Iterable[tuple[str, torch.Tensor]]) -> set[str]:
stacked_params_mapping = [
("qkv_proj", "q_proj", "q"),
("qkv_proj", "k_proj", "k"),
("qkv_proj", "v_proj", "v"),
("gate_up_proj", "gate_proj", 0),
("gate_up_proj", "up_proj", 1),
]
params_dict = dict(self.named_parameters())
loaded_params: set[str] = set()
for name, loaded_weight in weights:
if self.config.tie_word_embeddings and name.endswith("lm_head.weight"):
continue
if "rotary_emb.inv_freq" in name:
continue
if "mtp" in name:
name = self._rewrite_spec_layer_name(self.config, name)
for param_name, weight_name, shard_id in stacked_params_mapping:
# Skip non-stacked layers and experts (experts handled below).
if weight_name not in name:
continue
if "mtp" not in name:
continue
# We have mlp.experts[0].gate_proj in the checkpoint.
# Since we handle the experts below in expert_params_mapping,
# we need to skip here BEFORE we update the name, otherwise
# name will be updated to mlp.experts[0].gate_up_proj, which
# will then be updated below in expert_params_mapping
# for mlp.experts[0].gate_gate_up_proj, which breaks load.
if ("mlp.experts." in name) and name not in params_dict:
continue
name = name.replace(weight_name, param_name)
# Skip loading extra bias for GPTQ models.
if (
name.endswith(".bias") or name.endswith("_bias")
) and name not in params_dict:
continue
# Skip layers on other devices.
if is_pp_missing_parameter(name, self):
continue
param = params_dict[name]
weight_loader = param.weight_loader
weight_loader(param, loaded_weight, shard_id)
break
else:
# Skip loading extra bias for GPTQ models.
if (
name.endswith(".bias") or name.endswith("_bias")
) and name not in params_dict:
continue
# Skip layers on other devices.
if is_pp_missing_parameter(name, self):
continue
# According to DeepSeek-V3 Technical Report, MTP modules
# shares embedding layer. We only load the first weights.
if "mtp_" not in name and (
"embed_tokens" not in name and "lm_head" not in name
):
continue
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
def _rewrite_spec_layer_name(self, config: PretrainedConfig, name: str) -> str:
"""
Rewrite the weight name to match the format of the original model.
"""
spec_layer_weight_names = [
"embed_tokens",
"mtp_emb_norm",
"mtp_hidden_norm",
"mtp_linear_proj",
]
layer_idx = config.num_hidden_layers
for weight_name in spec_layer_weight_names:
if weight_name in name:
name = name.replace(
f"model.{weight_name}.0.",
f"model.layers.{layer_idx}.{weight_name}.",
)
return name
name = name.replace(
"model.mtp_block.0.", f"model.layers.{layer_idx}.mtp_block."
)
return name