# coding=utf-8 # Copyright 2023 The PygmalionAI team. # Copyright 2023 The vLLM team. # Copyright (c) Google Inc. # # 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 Gemma model compatible with HuggingFace weights.""" from functools import lru_cache from typing import List, Optional, Tuple import torch from torch import nn from transformers import GemmaConfig from aphrodite.attention import Attention, AttentionMetadata from aphrodite.modeling.layers.activation import GeluAndMul from aphrodite.modeling.layers.layernorm import RMSNorm from aphrodite.modeling.layers.linear import ( LinearMethodBase, MergedColumnParallelLinear, QKVParallelLinear, RowParallelLinear, ColumnParallelLinear, ) from aphrodite.modeling.layers.rotary_embedding import get_rope from aphrodite.modeling.layers.logits_processor import LogitsProcessor from aphrodite.modeling.layers.sampler import Sampler from aphrodite.modeling.layers.vocab_parallel_embedding import ( VocabParallelEmbedding, ParallelLMHead, ) from aphrodite.distributed import ( get_tensor_model_parallel_world_size, ) from aphrodite.modeling.sampling_metadata import SamplingMetadata from aphrodite.modeling.hf_downloader import ( default_weight_loader, hf_model_weights_iterator, ) from aphrodite.common.sequence import SamplerOutput @lru_cache(maxsize=None) def _get_gemma_act_fn( hidden_act: Optional[str], hidden_activation: Optional[str], ) -> nn.Module: if hidden_activation is None: if hidden_act is not None: hidden_activation = hidden_act return GeluAndMul(approximate="none") elif hidden_activation == "gelu_pytorch_tanh": return GeluAndMul(approximate="tanh") elif hidden_activation == "gelu": return GeluAndMul(approximate="none") else: raise ValueError(f"Activation function {hidden_act} is not " "supported for Gemma models.") class GemmaMLP(nn.Module): def __init__( self, hidden_size: int, intermediate_size: int, hidden_act: Optional[str] = None, hidden_activation: Optional[str] = None, linear_method: Optional[LinearMethodBase] = None, ) -> None: super().__init__() if (linear_method is not None and not linear_method.quant_config.merge_weight()): self.merge_weight = False self.gate_proj = ColumnParallelLinear( hidden_size, intermediate_size, bias=False, linear_method=linear_method, ) self.up_proj = ColumnParallelLinear( hidden_size, intermediate_size, bias=False, linear_method=linear_method, ) else: self.merge_weight = True self.gate_up_proj = MergedColumnParallelLinear( hidden_size, [intermediate_size] * 2, bias=False, linear_method=linear_method, ) self.down_proj = RowParallelLinear( intermediate_size, hidden_size, bias=False, linear_method=linear_method, ) self.act_fn = _get_gemma_act_fn(hidden_act, hidden_activation) def forward(self, x): if self.merge_weight: gate_up, _ = self.gate_up_proj(x) else: up, _ = self.up_proj(x) gate, _ = self.gate_proj(x) gate_up = torch.cat([gate, up], dim=-1) x = self.act_fn(gate_up) x, _ = self.down_proj(x) return x class GemmaAttention(nn.Module): def __init__( self, hidden_size: int, num_heads: int, num_kv_heads: int, head_dim: int, max_position_embeddings: int = 8192, rope_theta: float = 10000, linear_method: Optional[LinearMethodBase] = None, ) -> None: super().__init__() self.hidden_size = hidden_size tp_size = get_tensor_model_parallel_world_size() self.total_num_heads = num_heads assert self.total_num_heads % tp_size == 0 self.num_heads = self.total_num_heads // tp_size self.total_num_kv_heads = num_kv_heads if self.total_num_kv_heads >= tp_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_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_size % self.total_num_kv_heads == 0 self.num_kv_heads = max(1, self.total_num_kv_heads // tp_size) self.head_dim = head_dim self.q_size = self.num_heads * self.head_dim self.kv_size = self.num_kv_heads * self.head_dim self.scaling = self.head_dim**-0.5 self.rope_theta = rope_theta if (linear_method is not None and not linear_method.quant_config.merge_weight()): self.merge_weight = False self.q_proj = ColumnParallelLinear( hidden_size, self.total_num_heads * self.head_dim, bias=False, linear_method=linear_method, ) self.k_proj = ColumnParallelLinear( hidden_size, self.total_num_kv_heads * self.head_dim, bias=False, linear_method=linear_method, ) self.v_proj = ColumnParallelLinear( hidden_size, self.total_num_kv_heads * self.head_dim, bias=False, linear_method=linear_method, ) else: self.merge_weight = True self.qkv_proj = QKVParallelLinear( hidden_size, self.head_dim, self.total_num_heads, self.total_num_kv_heads, bias=False, linear_method=linear_method, ) self.o_proj = RowParallelLinear( self.total_num_heads * self.head_dim, hidden_size, bias=False, linear_method=linear_method, ) is_neox_style = (True if linear_method is None or linear_method.quant_config.rope_style() is None else linear_method.quant_config.rope_style()) self.rotary_emb = get_rope( self.head_dim, rotary_dim=self.head_dim, max_position=max_position_embeddings, base=self.rope_theta, is_neox_style=is_neox_style, ) self.attn = Attention( self.num_heads, self.head_dim, self.scaling, num_kv_heads=self.num_kv_heads, ) def forward( self, positions: torch.Tensor, hidden_states: torch.Tensor, kv_cache: torch.Tensor, attn_metadata: AttentionMetadata, ) -> torch.Tensor: if self.merge_weight: qkv, _ = self.qkv_proj(hidden_states) q, k, v = qkv.split([self.q_size, self.kv_size, self.kv_size], dim=-1) else: q, _ = self.q_proj(hidden_states) k, _ = self.k_proj(hidden_states) v, _ = self.v_proj(hidden_states) q, k = self.rotary_emb(positions, q, k) attn_output = self.attn(q, k, v, kv_cache, attn_metadata) output, _ = self.o_proj(attn_output) return output class GemmaDecoderLayer(nn.Module): def __init__( self, config: GemmaConfig, linear_method: Optional[LinearMethodBase] = None, ) -> None: super().__init__() self.hidden_size = config.hidden_size self.self_attn = GemmaAttention( hidden_size=self.hidden_size, num_heads=config.num_attention_heads, num_kv_heads=config.num_key_value_heads, head_dim=config.head_dim, max_position_embeddings=config.max_position_embeddings, rope_theta=config.rope_theta, linear_method=linear_method, ) self.mlp = GemmaMLP( hidden_size=self.hidden_size, intermediate_size=config.intermediate_size, hidden_act=config.hidden_act, hidden_activation=getattr(config, "hidden_activation", None), linear_method=linear_method, ) self.input_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps) self.post_attention_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps) def forward( self, positions: torch.Tensor, hidden_states: torch.Tensor, kv_cache: torch.Tensor, attn_metadata: AttentionMetadata, residual: Optional[torch.Tensor], ) -> Tuple[torch.Tensor, torch.Tensor]: # Self Attention if residual is None: residual = hidden_states hidden_states = self.input_layernorm(hidden_states) else: hidden_states, residual = self.input_layernorm( hidden_states, residual) hidden_states = self.self_attn( positions=positions, hidden_states=hidden_states, kv_cache=kv_cache, attn_metadata=attn_metadata, ) # Fully Connected hidden_states, residual = self.post_attention_layernorm( hidden_states, residual) hidden_states = self.mlp(hidden_states) return hidden_states, residual class GemmaModel(nn.Module): def __init__( self, config: GemmaConfig, linear_method: Optional[LinearMethodBase] = None, ) -> None: super().__init__() self.config = config self.embed_tokens = VocabParallelEmbedding(config.vocab_size, config.hidden_size, linear_method=linear_method) self.layers = nn.ModuleList([ GemmaDecoderLayer(config, linear_method) for _ in range(config.num_hidden_layers) ]) self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps) # Normalize the embedding by sqrt(hidden_size) # The normalizer's data type should be downcasted to the model's # data type such as bfloat16, not float32. # See https://github.com/huggingface/transformers/pull/29402 normalizer = self.config.hidden_size**0.5 self.register_buffer("normalizer", torch.tensor(normalizer)) def forward( self, input_ids: torch.Tensor, positions: torch.Tensor, kv_caches: List[torch.Tensor], attn_metadata: AttentionMetadata, ) -> torch.Tensor: hidden_states = self.embed_tokens(input_ids) hidden_states *= self.normalizer residual = None for i in range(len(self.layers)): layer = self.layers[i] hidden_states, residual = layer( positions, hidden_states, kv_caches[i], attn_metadata, residual, ) hidden_states, _ = self.norm(hidden_states, residual) return hidden_states class GemmaForCausalLM(nn.Module): def __init__( self, config: GemmaConfig, linear_method: Optional[LinearMethodBase] = None, ) -> None: super().__init__() self.config = config self.linear_method = linear_method self.model = GemmaModel(config, linear_method) self.lm_head = ParallelLMHead(config.vocab_size, config.hidden_size, linear_method=linear_method) self.logits_processor = LogitsProcessor(config.vocab_size, config.tokenizer_vocab_size) self.sampler = Sampler() @torch.no_grad() def forward( self, input_ids: torch.Tensor, positions: torch.Tensor, kv_caches: List[torch.Tensor], attn_metadata: AttentionMetadata, ) -> torch.Tensor: hidden_states = self.model(input_ids, positions, kv_caches, attn_metadata) return hidden_states def compute_logits(self, hidden_states: torch.Tensor, sampling_metadata: SamplingMetadata) -> torch.Tensor: logits = self.logits_processor(self.lm_head, hidden_states, sampling_metadata) return logits def sample( self, logits: torch.Tensor, sampling_metadata: SamplingMetadata, ) -> Optional[SamplerOutput]: next_tokens = self.sampler(logits, sampling_metadata) return next_tokens def load_weights( self, model_name_or_path: str, cache_dir: Optional[str] = None, load_format: str = "auto", revision: Optional[str] = None, ): 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), ] if (self.linear_method is not None and not self.linear_method.quant_config.merge_weight()): stacked_params_mapping = [] params_dict = dict(self.named_parameters()) loaded_params = set() for name, loaded_weight in hf_model_weights_iterator( model_name_or_path, cache_dir, load_format, revision, self.config): if "rotary_emb.inv_freq" in name: continue if "embed_tokens" in name: # Copy word embedding to lm_head head_name = name.replace("model.embed_tokens", "lm_head") if head_name in params_dict: loaded_params.add(head_name) lm_head_param = params_dict[head_name] weight_loader = getattr(lm_head_param, "weight_loader", default_weight_loader) weight_loader(lm_head_param, loaded_weight) 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: if "lm_head.weight" in name: continue # Skip loading extra layer for lora models. if "lm_head" in name and name not in params_dict: continue # GemmaRMSNorm is different from Llama's in that it multiplies # (1 + weight) to the output, instead of just weight. if "norm.weight" in name: loaded_weight += 1.0 param = params_dict[name] weight_loader = getattr(param, "weight_loader", default_weight_loader) weight_loader(param, loaded_weight) loaded_params.add(name) unloaded_params = params_dict.keys() - loaded_params if unloaded_params: raise RuntimeError( "Some weights are not initialized from checkpoints: " f"{unloaded_params}")