Remove mpt.

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Nicolas Patry 2023-06-30 07:52:01 +00:00
parent da7e104241
commit 0a50ac31a7

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@ -1,361 +0,0 @@
"""A simple, flexible implementation of a GPT model.
Inspired by https://github.com/karpathy/minGPT/blob/master/mingpt/model.py
"""
# import math
# import warnings
# from typing import List, Optional, Tuple, Union
# import torch
# import torch.nn as nn
# import torch.nn.functional as F
# from transformers import PreTrainedModel, PreTrainedTokenizer, PreTrainedTokenizerFast
# from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast
# from .attention import attn_bias_shape, build_attn_bias
# from .blocks import MPTBlock
# from .custom_embedding import SharedEmbedding
# from .norm import NORM_CLASS_REGISTRY
# from .configuration_mpt import MPTConfig
# from .adapt_tokenizer import AutoTokenizerForMOD, adapt_tokenizer_for_denoising
# from .hf_prefixlm_converter import add_bidirectional_mask_if_missing, convert_hf_causal_lm_to_prefix_lm
# from .meta_init_context import init_empty_weights
# from .param_init_fns import MODEL_INIT_REGISTRY, generic_param_init_fn_
# try:
# from .flash_attn_triton import flash_attn_func
# except:
# pass
"""GPT Blocks used for the GPT Model."""
from typing import Dict, Optional, Tuple
import torch
import torch.nn as nn
import math
from text_generation_server.utils.layers import (
TensorParallelRowLinear,
TensorParallelColumnLinear,
TensorParallelEmbedding,
PositionRotaryEmbedding,
TensorParallelHead,
FastLayerNorm,
)
EPS = 1e-5
def _gen_slopes(n_heads, alibi_bias_max=8, device=None):
_n_heads = 2 ** math.ceil(math.log2(n_heads))
m = torch.arange(1, _n_heads + 1, dtype=torch.float32, device=device)
m = m.mul(alibi_bias_max / _n_heads)
slopes = 1.0 / torch.pow(2, m)
if _n_heads != n_heads:
slopes = torch.concat([slopes[1::2], slopes[::2]])[:n_heads]
return slopes.view(1, n_heads, 1, 1)
def _build_alibi_bias(n_heads, seq_len, device, dtype, alibi_bias_max):
alibi_bias = torch.arange(1 - seq_len, 1, dtype=torch.int32, device=device).view(1, 1, 1, seq_len)
slopes = _gen_slopes(n_heads, alibi_bias_max, device=device)
alibi_bias = alibi_bias * slopes
return alibi_bias.to(dtype=dtype)
ALIBI = None
def build_alibi_bias(n_heads, seq_len, device, dtype, alibi_bias_max=8):
global ALIBI
if ALIBI is None or seq_len > ALIBI.shape[-1]:
ALIBI = _build_alibi_bias(n_heads, seq_len, device, dtype, alibi_bias_max=alibi_bias_max)
return ALIBI[:, :, :, :seq_len]
class MPTAttention(nn.Module):
def __init__(self, config, prefix, weights):
super().__init__()
self.num_heads = config.n_heads
self.hidden_size = config.d_model
self.head_size = self.hidden_size // self.num_heads
self.Wqkv = TensorParallelColumnLinear.load(
config,
prefix=f"{prefix}.Wqkv",
weights=weights,
bias=False,
)
self.out_proj = TensorParallelRowLinear.load(
config,
prefix=f"{prefix}.out_proj",
weights=weights,
bias=False,
)
def forward(self,
hidden_states,
alibi,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_key_values,
past_present_indices,
prefill,
):
qkv = self.Wqkv(hidden_states)
qkv = qkv.view(-1, 3, self.num_heads, self.head_size)
# Todo
raise Exception("Apply alibi ?");
# Prefill
if prefill:
# Copy to layer past
layer_past[...] = qkv[:, 1:]
# output
attn_output = torch.empty_like(qkv[:, 0])
# flash attention
flash_attn_cuda.fwd(
qkv[:, 0],
qkv[:, 1],
qkv[:, 2],
attn_output,
start_seq,
end_seq,
start_seq,
end_seq,
max_s,
max_s,
0.0,
self.softmax_scale,
False,
True,
False,
0,
None,
)
# Decode
else:
query = qkv[:, 0]
# Add present to the layer_past tensor at the correct indices
layer_past[past_present_indices] = qkv[:, 1:]
# output
attn_output = torch.empty_like(query)
# flash attention
flash_attn_cuda.fwd(
query,
layer_past[:, 0],
layer_past[:, 1],
attn_output,
start_seq_q,
end_seq_q,
start_seq,
end_seq,
1,
max_s,
0.0,
self.softmax_scale,
False,
False,
False,
0,
None,
)
return self.o_proj(attn_output.view(-1, self.num_heads * self.head_size))
class MPTMLP(nn.Module):
def __init__(self, config, prefix, weights):
super().__init__()
self.up_proj = TensorParallelColumnLinear.load(
config,
prefix=f"{prefix}.up_proj",
weights=weights,
bias=False,
)
self.act = nn.GELU(approximate='none')
self.down_proj = TensorParallelRowLinear.load(
config,
prefix=f"{prefix}.down_proj",
weights=weights,
bias=False,
)
def forward(self, x):
return self.down_proj(self.act(self.up_proj(x)))
class MPTBlock(nn.Module):
def __init__(self, config, prefix, weights):
super().__init__()
self.norm_1 = FastLayerNorm.load_no_bias(prefix=f"{prefix}.norm_1", weights=weights, eps=EPS)
self.attn = MPTAttention(config, prefix=f"{prefix}.attn", weights=weights)
self.norm_2 = FastLayerNorm.load_no_bias(prefix=f"{prefix}.norm_2", weights=weights, eps=EPS)
self.ffn = MPTMLP(config, prefix=f"{prefix}.ffn", weights=weights)
def forward(self,
hidden_states,
residual,
alibi,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_key_values,
past_present_indices,
prefill,
):
residual = hidden_states
hidden_states, _ = self.norm_1(hidden_states)
# (hidden_states, attn_weights) = self.attn(
hidden_states = self.attn(
hidden_states,
alibi,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_key_values,
past_present_indices,
prefill,
)
hidden_states += residual
residual = hidden_states
hidden_states, _ = self.norm_2(hidden_states)
hidden_states = self.ffn(hidden_states)
hidden_states += residual
return (x, attn_weights)
class MPTModel(nn.Module):
def __init__(self, config, weights):
super().__init__()
self.wte = TensorParallelEmbedding(
prefix="transformer.wte", weights=weights
)
self.num_heads = config.n_heads
self.hidden_size = config.d_model
self.head_size = self.hidden_size // self.num_heads
self.blocks = nn.ModuleList([MPTBlock(config, prefix=f"transformer.blocks.{i}", weights=weights) for i in range(config.n_layers)])
self.norm_f = FastLayerNorm.load_no_bias(
prefix="transformer.norm_f", weights=weights, eps=EPS
)
# Create a default sizeable global alibi
build_alibi_bias(n_heads=self.num_heads, seq_len=1024,device=weights.device, dtype = weights.dtype)
def forward(
self,
input_ids,
position_ids,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_present_indices,
past_key_values=None,
pre_allocate_past_size: Optional[int] = None,
):
hidden_states = self.wte(input_ids)
# Prefill
if past_key_values is None:
assert pre_allocate_past_size is not None
prefill = True
# Create past tensor
# We create a tensor of the same size as input_ids as we don't want to slice at every layer
past_key_values = hidden_states.new_empty(
(
len(input_ids),
len(self.blocks),
2,
self.num_heads,
self.head_size,
)
)
# Decode
else:
prefill = False
alibi = build_alibi_bias(n_heads=self.num_heads, seq_len=max_s,device=hidden_states.device, dtype = hidden_states.dtype)
# Cast alibi into correct shape
alibi = alibi[:, :, :, position_ids]
residual = None
for i, layer in enumerate(self.blocks):
hidden_states, residual = layer(
hidden_states,
residual,
alibi,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_key_values[:, i],
past_present_indices,
prefill,
)
if prefill:
present = past_key_values
# Create padded past tensor
past_key_values = hidden_states.new_empty(
(
pre_allocate_past_size,
len(self.blocks),
2,
self.num_heads,
self.head_size,
)
)
# We slice only once instead of at every layer
past_key_values[past_present_indices] = present
hidden_states, _ = self.norm_f(hidden_states, residual)
return hidden_states, past_key_values
class MPTForCausalLM(nn.Module):
def __init__(self, config, weights):
super().__init__()
self.transformer = MPTModel(config, weights)
self.lm_head = TensorParallelHead.load(
config,
prefix="transformer.wte",
weights=weights,
)
def forward(
self,
input_ids,
position_ids,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_present_indices,
past_key_values: Optional[torch.Tensor] = None,
pre_allocate_past_size: Optional[int] = None,
lm_head_indices: Optional[torch.Tensor] = None,
):
hidden_states, present = self.transformer(
input_ids,
position_ids,
start_seq,
end_seq,
start_seq_q,
end_seq_q,
max_s,
past_present_indices,
past_key_values,
pre_allocate_past_size,
)
if lm_head_indices is not None:
hidden_states = hidden_states[lm_head_indices]
logits = self.lm_head(hidden_states)
return logits, present