Qubitium-ModelCloud ee93f4f92a
[CORE] Quantized lm-head Framework (#4442)
Co-authored-by: Robert Shaw <rshaw@neuralmagic.com>
Co-authored-by: ZX <zx@lbx.dev>
2024-07-02 22:25:17 +00:00

340 lines
12 KiB
Python

# coding=utf-8
# Adapted from
# https://huggingface.co/core42/jais-30b-chat-v3/blob/main/modeling_jais.py
# Copyright 2023 The vLLM team.
# Copyright 2023 the Jais authors and HuggingFace Inc. team. All rights
# reserved.
# Copyright 2023 Cerebras Systems.
#
# 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 Jais model compatible with HuggingFace weights."""
import math
from typing import Iterable, List, Optional, Tuple
import torch
from torch import nn
from vllm.attention import Attention, AttentionMetadata
from vllm.config import CacheConfig
from vllm.distributed import (get_tensor_model_parallel_rank,
get_tensor_model_parallel_world_size)
from vllm.model_executor.layers.linear import (ColumnParallelLinear,
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 Sampler
from vllm.model_executor.layers.vocab_parallel_embedding import (
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, SamplerOutput
from vllm.transformers_utils.configs import JAISConfig
class SwiGLUActivation(nn.Module):
def forward(self, x1: torch.Tensor, x2: torch.Tensor) -> torch.Tensor:
return x1 * nn.functional.silu(x2)
def _get_alibi_slopes(n):
def get_slopes_power_of_2(n):
start = 2**(-(2**-(math.log2(n) - 3)))
ratio = start
return [start * ratio**i for i in range(n)]
if math.log2(n).is_integer():
return get_slopes_power_of_2(n)
else:
closest_power_of_2 = 2**math.floor(math.log2(n))
return (get_slopes_power_of_2(closest_power_of_2) + _get_alibi_slopes(
2 * closest_power_of_2)[0::2][:n - closest_power_of_2])
class JAISAttention(nn.Module):
def __init__(
self,
config: JAISConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
self.hidden_size = config.hidden_size
total_num_heads = config.num_attention_heads
tensor_model_parallel_world_size = (
get_tensor_model_parallel_world_size())
assert total_num_heads % tensor_model_parallel_world_size == 0
self.num_heads = total_num_heads // tensor_model_parallel_world_size
self.head_dim = self.hidden_size // total_num_heads
if hasattr(config, "scale_qk_dot_by_d"):
config.mup_scale_qk_dot_by_d = config.scale_qk_dot_by_d
self.attn_scale_power = 1.0 if config.mup_scale_qk_dot_by_d else 0.5
self.scale = self.head_dim**-self.attn_scale_power
self.c_attn = QKVParallelLinear(
self.hidden_size,
self.head_dim,
total_num_heads,
bias=True,
quant_config=quant_config,
)
self.c_proj = RowParallelLinear(
self.hidden_size,
self.hidden_size,
bias=True,
quant_config=quant_config,
)
tp_rank = get_tensor_model_parallel_rank()
head_start = tp_rank * self.num_heads
head_end = (tp_rank + 1) * self.num_heads
alibi_slopes = _get_alibi_slopes(total_num_heads)
alibi_slopes = alibi_slopes[head_start:head_end]
self.attn = Attention(self.num_heads,
self.head_dim,
scale=self.scale,
alibi_slopes=alibi_slopes,
cache_config=cache_config,
quant_config=quant_config)
def forward(
self,
hidden_states: torch.Tensor,
kv_cache: torch.Tensor,
attn_metadata: AttentionMetadata,
) -> torch.Tensor:
qkv, _ = self.c_attn(hidden_states)
q, k, v = qkv.chunk(chunks=3, dim=-1)
attn_output = self.attn(q, k, v, kv_cache, attn_metadata)
attn_output, _ = self.c_proj(attn_output)
return attn_output
class JAISMLP(nn.Module):
def __init__(
self,
intermediate_size: int,
config: JAISConfig,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
hidden_size = config.hidden_size
self.swiglu = config.activation_function == "swiglu"
self.c_fc = ColumnParallelLinear(
hidden_size,
intermediate_size,
bias=True,
quant_config=quant_config,
)
self.c_fc2 = (ColumnParallelLinear(
hidden_size,
intermediate_size,
bias=True,
quant_config=quant_config,
) if self.swiglu else None)
self.c_proj = RowParallelLinear(
intermediate_size,
hidden_size,
bias=True,
quant_config=quant_config,
)
self.act = SwiGLUActivation()
def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
if self.swiglu:
hidden_states2, _ = self.c_fc2(hidden_states)
hidden_states, _ = self.c_fc(hidden_states)
hidden_states = (self.act(hidden_states, hidden_states2)
if self.swiglu else self.act(hidden_states))
hidden_states, _ = self.c_proj(hidden_states)
return hidden_states
class JAISBlock(nn.Module):
def __init__(
self,
config: JAISConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
hidden_size = config.hidden_size
inner_dim = (config.n_inner if config.n_inner is not None else 4 *
hidden_size)
self.ln_1 = nn.LayerNorm(hidden_size, eps=config.layer_norm_epsilon)
self.attn = JAISAttention(config, cache_config, quant_config)
self.ln_2 = nn.LayerNorm(hidden_size, eps=config.layer_norm_epsilon)
self.mlp = JAISMLP(inner_dim, config, quant_config)
def forward(
self,
hidden_states: torch.Tensor,
kv_cache: torch.Tensor,
attn_metadata: AttentionMetadata,
) -> torch.Tensor:
residual = hidden_states
hidden_states = self.ln_1(hidden_states)
attn_output = self.attn(
hidden_states=hidden_states,
kv_cache=kv_cache,
attn_metadata=attn_metadata,
)
# residual connection
hidden_states = attn_output + residual
residual = hidden_states
hidden_states = self.ln_2(hidden_states)
feed_forward_hidden_states = self.mlp(hidden_states)
# residual connection
hidden_states = residual + feed_forward_hidden_states
return hidden_states
class JAISModel(nn.Module):
def __init__(
self,
config: JAISConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
self.config = config
assert not config.add_cross_attention
assert not config.scale_attn_by_inverse_layer_idx
assert not config.reorder_and_upcast_attn
self.embed_dim = config.hidden_size
self.wte = VocabParallelEmbedding(config.vocab_size, self.embed_dim)
self.wpe = (nn.Embedding(config.max_position_embeddings,
self.embed_dim)
if config.position_embedding_type != "alibi" else None)
if hasattr(config, "embeddings_scale"):
self.embeddings_scale = config.embeddings_scale
else:
self.embeddings_scale = config.mup_embeddings_scale
self.h = nn.ModuleList([
JAISBlock(config, cache_config, quant_config)
for _ in range(config.num_hidden_layers)
])
self.ln_f = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_epsilon)
def forward(
self,
input_ids: torch.Tensor,
position_ids: torch.Tensor,
kv_caches: List[torch.Tensor],
attn_metadata: AttentionMetadata,
) -> torch.Tensor:
inputs_embeds = self.wte(input_ids)
if self.wpe is not None:
position_embeds = self.wpe(position_ids)
hidden_states = inputs_embeds + position_embeds
else:
hidden_states = inputs_embeds
hidden_states *= torch.tensor(float(self.embeddings_scale),
dtype=hidden_states.dtype)
for i in range(len(self.h)):
layer = self.h[i]
hidden_states = layer(hidden_states, kv_caches[i], attn_metadata)
hidden_states = self.ln_f(hidden_states)
return hidden_states
class JAISLMHeadModel(nn.Module):
def __init__(
self,
config: JAISConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None,
):
super().__init__()
self.config = config
self.quant_config = quant_config
self.transformer = JAISModel(config, cache_config, quant_config)
self.lm_head = self.transformer.wte
if hasattr(config, "width_scale"):
self.output_logits_scale = config.width_scale
else:
self.output_logits_scale = (config.mup_output_alpha *
config.mup_width_scale)
self.logits_processor = LogitsProcessor(vocab_size=config.vocab_size,
scale=self.output_logits_scale)
self.sampler = Sampler()
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
kv_caches: List[torch.Tensor],
attn_metadata: AttentionMetadata,
intermediate_tensors: Optional[IntermediateTensors] = None,
) -> torch.Tensor:
hidden_states = self.transformer(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, weights: Iterable[Tuple[str, torch.Tensor]]):
params_dict = dict(self.named_parameters(remove_duplicate=False))
for name, loaded_weight in weights:
if "lm_head.weight" in name:
# GPT-2 ties the weights of the embedding layer and the final
# linear layer.
continue
if ".attn.bias" in name or ".attn.masked_bias" in name:
# Skip attention mask.
# NOTE: "c_attn.bias" should not be skipped.
continue
if "relative_pe" in name:
continue
if not name.startswith("transformer."):
name = "transformer." + name
param = params_dict[name]
# The HF's GPT-2 implementation uses Conv1D instead of Linear.
# Because of this, we need to transpose the weights.
# Note(zhuohan): the logic below might break quantized models.
for conv1d_weight_name in ["c_attn", "c_proj", "c_fc"]:
if conv1d_weight_name not in name:
continue
if not name.endswith(".weight"):
continue
loaded_weight = loaded_weight.t()
weight_loader = getattr(param, "weight_loader",
default_weight_loader)
weight_loader(param, loaded_weight)