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sglang/python/sglang/srt/models/olmo.py
2024-11-18 13:00:02 -08:00

353 lines
12 KiB
Python

"""
Copyright 2023-2024 SGLang Team
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.
"""
# Adapted from
# https://github.com/vllm-project/vllm/blob/c7f2cf2b7f67bce5842fedfdba508440fe257375/vllm/model_executor/models/olmo.py#L1
"""Inference-only OLMo model compatible with HuggingFace weights."""
from typing import Iterable, List, Optional, Tuple
import torch
from torch import nn
from transformers import OlmoConfig
from vllm.distributed import get_tensor_model_parallel_world_size
from vllm.model_executor.layers.rotary_embedding import get_rope
from vllm.model_executor.model_loader.weight_utils import default_weight_loader
from sglang.srt.layers.activation import SiluAndMul
from sglang.srt.layers.linear import (
MergedColumnParallelLinear,
QKVParallelLinear,
RowParallelLinear,
)
from sglang.srt.layers.logits_processor import LogitsProcessor
from sglang.srt.layers.quantization.base_config import QuantizationConfig
from sglang.srt.layers.radix_attention import RadixAttention
from sglang.srt.layers.vocab_parallel_embedding import (
ParallelLMHead,
VocabParallelEmbedding,
)
from sglang.srt.model_executor.forward_batch_info import ForwardBatch
class OlmoAttention(nn.Module):
"""
This is the attention block where the output is computed as
``Attention(LN(x))`` in ``MLP(LN(x + Attention(LN(x))))``
(plus another skip connection).
"""
def __init__(
self,
config: OlmoConfig,
layer_id: int = 0,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
self.config = config
self.hidden_size = config.hidden_size
tensor_model_parallel_world_size = get_tensor_model_parallel_world_size()
self.total_num_heads = config.num_attention_heads
assert self.hidden_size % self.total_num_heads == 0
assert self.total_num_heads % tensor_model_parallel_world_size == 0
self.num_heads = self.total_num_heads // tensor_model_parallel_world_size
self.head_dim = self.hidden_size // self.total_num_heads
self.max_position_embeddings = config.max_position_embeddings
self.rope_theta = config.rope_theta
self.clip_qkv = config.clip_qkv
# Attention input projection. Projects x -> (q, k, v)
self.qkv_proj = QKVParallelLinear(
self.hidden_size,
self.head_dim,
self.total_num_heads,
bias=config.attention_bias,
)
# Rotary embeddings.
self.rotary_emb = get_rope(
self.head_dim,
rotary_dim=self.head_dim,
max_position=self.max_position_embeddings,
base=self.rope_theta,
)
self.scaling = self.head_dim**-0.5
self.attn = RadixAttention(
self.num_heads,
self.head_dim,
self.scaling,
num_kv_heads=self.num_heads,
layer_id=layer_id,
)
# Attention output projection.
self.o_proj = RowParallelLinear(
self.hidden_size,
self.hidden_size,
bias=config.attention_bias,
)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
) -> torch.Tensor:
qkv, _ = self.qkv_proj(hidden_states)
if self.clip_qkv is not None:
qkv.clamp_(min=-self.clip_qkv, max=self.clip_qkv)
q, k, v = qkv.chunk(chunks=3, dim=-1)
q, k = self.rotary_emb(positions, q, k)
attn_output = self.attn(q, k, v, forward_batch)
output, _ = self.o_proj(attn_output)
return output
class OlmoMLP(nn.Module):
"""
This is the MLP block where the output is computed as
``MLP(LN(x))`` in ``MLP(LN(x + Attention(LN(x))))``
(plus another skip connection).
"""
def __init__(
self,
config: OlmoConfig,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
self.config = config
self.hidden_size = config.hidden_size
self.intermediate_size = config.intermediate_size
# Feed-forward input projection.
self.gate_up_proj = MergedColumnParallelLinear(
self.hidden_size,
[self.intermediate_size] * 2,
bias=False,
quant_config=quant_config,
)
# Activation function.
self.act_fn = SiluAndMul()
# Feed-forward output projection.
self.down_proj = RowParallelLinear(
self.intermediate_size,
self.hidden_size,
bias=False,
quant_config=quant_config,
)
def forward(
self,
x: torch.Tensor,
) -> torch.Tensor:
gate_up, _ = self.gate_up_proj(x)
x = self.act_fn(gate_up)
x, _ = self.down_proj(x)
return x
class OlmoDecoderLayer(nn.Module):
"""
This is a typical transformer block where the output is
computed as ``MLP(LN(x + Attention(LN(x))))``
(plus another skip connection).
"""
def __init__(
self,
config: OlmoConfig,
layer_id: int = 0,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
# Attention block.
self.self_attn = OlmoAttention(config, layer_id, quant_config)
# MLP block.
self.mlp = OlmoMLP(config, quant_config)
# LayerNorm
self.input_layernorm = nn.LayerNorm(
config.hidden_size, elementwise_affine=False, bias=False
)
self.post_attention_layernorm = nn.LayerNorm(
config.hidden_size, elementwise_affine=False, bias=False
)
def forward(
self,
positions: torch.Tensor,
hidden_states: torch.Tensor,
forward_batch: ForwardBatch,
) -> Tuple[torch.Tensor, Optional[Tuple[torch.Tensor, torch.Tensor]]]:
# Attention block.
residual = hidden_states
hidden_states = self.input_layernorm(hidden_states)
hidden_states = self.self_attn(positions, hidden_states, forward_batch)
hidden_states = hidden_states + residual
# MLP block.
residual = hidden_states
hidden_states = self.post_attention_layernorm(hidden_states)
hidden_states = self.mlp(hidden_states)
hidden_states = residual + hidden_states
return hidden_states
class OlmoModel(nn.Module):
def __init__(
self, config: OlmoConfig, quant_config: Optional[QuantizationConfig] = None
):
super().__init__()
self.config = config
self.embed_tokens = VocabParallelEmbedding(
config.vocab_size, config.hidden_size
)
self.layers = nn.ModuleList(
[
OlmoDecoderLayer(config, layer_id, quant_config)
for layer_id in range(config.num_hidden_layers)
]
)
self.norm = nn.LayerNorm(
config.hidden_size, elementwise_affine=False, bias=False
)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
forward_batch: ForwardBatch,
input_embeds: torch.Tensor = None,
) -> torch.Tensor:
"""
:param input_ids: A tensor of shape `(batch_size, seq_len)`.
"""
# Get embeddings of input.
# shape: (batch_size, seq_len, d_model)
if input_embeds is None:
hidden_states = self.embed_tokens(input_ids)
else:
hidden_states = input_embeds
# Apply blocks one-by-one.
for layer_id, decoder_layer in enumerate(self.layers):
# shape: (batch_size, seq_len, d_model)
hidden_states = decoder_layer(
positions,
hidden_states,
forward_batch,
)
# Apply final layer norm.
# shape: (batch_size, seq_len or 1, d_model)
hidden_states = self.norm(hidden_states)
return hidden_states
class OlmoForCausalLM(nn.Module):
"""
Extremely barebones HF model wrapper.
"""
def __init__(
self,
config: OlmoConfig,
cache_config=None,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
self.config = config
self.model = OlmoModel(config, quant_config)
if config.tie_word_embeddings:
self.lm_head = self.model.embed_tokens
else:
self.unpadded_vocab_size = config.vocab_size
self.lm_head = ParallelLMHead(
self.unpadded_vocab_size,
config.hidden_size,
org_num_embeddings=config.vocab_size,
quant_config=quant_config,
)
self.logits_processor = LogitsProcessor(config)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
forward_batch: ForwardBatch,
input_embeds: torch.Tensor = None,
) -> torch.Tensor:
hidden_states = self.model(
input_ids=input_ids,
positions=positions,
forward_batch=forward_batch,
input_embeds=input_embeds,
)
return self.logits_processor(
input_ids, hidden_states, self.lm_head.weight, forward_batch
)
def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
stacked_params_mapping = [
# (param_name, shard_name, shard_id)
("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(remove_duplicate=False))
for name, loaded_weight in weights:
if "rotary_emb.inv_freq" in name:
continue
if "rotary_emb.cos_cached" in name or "rotary_emb.sin_cached" in name:
# Models trained using ColossalAI may include these tensors in
# the checkpoint. Skip them.
continue
# With tie_word_embeddings, we can skip lm_head.weight
# The weight might appear unnecessarily in the files if the model is
# processed with quantization, LoRA, fine-tuning, etc.
if self.config.tie_word_embeddings and "lm_head.weight" in name:
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)
# Skip loading extra bias for GPTQ models.
if name.endswith(".bias") and name not in params_dict:
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") and name not in params_dict:
continue
param = params_dict[name]
weight_loader = getattr(param, "weight_loader", default_weight_loader)
weight_loader(param, loaded_weight)
EntryClass = OlmoForCausalLM