AutoGPTQ/auto_gptq/nn_modules/fused_llama_attn.py
2023-08-07 19:00:05 +09:00

242 lines
10 KiB
Python

import math
import torch
import torch.nn as nn
from torch.nn import functional as F
from transformers.models.llama.modeling_llama import LlamaAttention, apply_rotary_pos_emb, repeat_kv
from ._fused_base import FusedBaseAttentionModule
from ..utils.import_utils import compare_pytorch_version, dynamically_import_QuantLinear
class FusedLlamaAttentionForQuantizedModel(FusedBaseAttentionModule):
"""Multi-headed attention from 'Attention Is All You Need' paper"""
def __init__(
self,
config,
qkv_proj,
o_proj,
rotary_emb,
):
super().__init__()
self.config = config
self.hidden_size = config.hidden_size
self.num_heads = config.num_attention_heads
self.head_dim = self.hidden_size // self.num_heads
self.num_key_value_heads = config.num_key_value_heads
self.num_key_value_groups = self.num_heads // self.num_key_value_heads
self.max_position_embeddings = config.max_position_embeddings
if (self.head_dim * self.num_heads) != self.hidden_size:
raise ValueError(
f"hidden_size must be divisible by num_heads (got `hidden_size`: {self.hidden_size}"
f" and `num_heads`: {self.num_heads})."
)
if self.config.pretraining_tp > 1:
raise NotImplementedError(f"pretraining_tp of 2 or more is currently not supported.")
if len(qkv_proj) == 1:
self.qkv_mode = 'qkv'
self.qkv_proj = qkv_proj[0]
elif len(qkv_proj) == 2:
self.qkv_mode = 'q,kv'
self.q_proj = qkv_proj[0]
self.kv_proj = qkv_proj[1]
self.o_proj = o_proj
self.rotary_emb = rotary_emb
def _shape(self, tensor, seq_len, bsz):
return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
def forward(
self,
hidden_states,
attention_mask=None,
position_ids=None,
past_key_value=None,
output_attentions=False,
use_cache=False,
**kwargs
):
"""Input shape: Batch x Time x Channel"""
bsz, q_len, _ = hidden_states.size()
if self.qkv_mode == 'qkv':
qkv_states = self.qkv_proj(hidden_states)
query_states, key_states, value_states = torch.split(qkv_states, self.hidden_size, dim=2)
elif self.qkv_mode == 'q,kv':
query_states = self.q_proj(hidden_states)
kv_states = self.kv_proj(hidden_states)
key_states, value_states = torch.split(kv_states, self.hidden_size, dim=2)
query_states = query_states.view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
key_states = key_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
value_states = value_states.view(bsz, q_len, self.num_key_value_heads, self.head_dim).transpose(1, 2)
kv_seq_len = key_states.shape[-2]
if past_key_value is not None:
kv_seq_len += past_key_value[0].shape[-2]
cos, sin = self.rotary_emb(value_states, seq_len=kv_seq_len)
query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
# [bsz, nh, t, hd]
is_causal = past_key_value is None
if past_key_value is not None:
# reuse k, v, self_attention
key_states = torch.cat([past_key_value[0], key_states], dim=2)
value_states = torch.cat([past_key_value[1], value_states], dim=2)
if use_cache:
# Since qkv_proj is fused, query_states etc will hold a reference to the original qkv_states tensor
# which can cause excessive memory usage by the cache. `contiguous` is a convenient way to workaround this.
query_states = query_states.contiguous()
key_states = key_states.contiguous()
value_states = value_states.contiguous()
past_key_value = (key_states, value_states) if use_cache else None
# repeat k/v heads if n_kv_heads < n_heads
key_states = repeat_kv(key_states, self.num_key_value_groups)
value_states = repeat_kv(value_states, self.num_key_value_groups)
if compare_pytorch_version("v2.0.0", op="eq"):
attn_output = F.scaled_dot_product_attention(
query_states,
key_states,
value_states,
attn_mask=None if is_causal else attention_mask,
is_causal=is_causal
)
attn_weights = None
else:
attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
if attn_weights.size() != (bsz, self.num_heads, q_len, kv_seq_len):
raise ValueError(
f"Attention weights should be of size {(bsz, self.num_heads, q_len, kv_seq_len)}, but is"
f" {attn_weights.size()}"
)
if attention_mask is not None:
if attention_mask.size() != (bsz, 1, q_len, kv_seq_len):
raise ValueError(
f"Attention mask should be of size {(bsz, 1, q_len, kv_seq_len)}, but is {attention_mask.size()}"
)
attn_weights = attn_weights + attention_mask
# upcast attention to fp32
attn_weights = nn.functional.softmax(attn_weights, dim=-1, dtype=torch.float32).to(query_states.dtype)
attn_output = torch.matmul(attn_weights, value_states)
if attn_output.size() != (bsz, self.num_heads, q_len, self.head_dim):
raise ValueError(
f"`attn_output` should be of size {(bsz, self.num_heads, q_len, self.head_dim)}, but is"
f" {attn_output.size()}"
)
attn_output = attn_output.transpose(1, 2)
attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
attn_output = self.o_proj(attn_output)
if not output_attentions:
attn_weights = None
return attn_output, attn_weights, past_key_value
@classmethod
def inject_to_model(
cls,
model,
use_triton=False,
group_size=-1,
use_cuda_fp16=True,
desc_act=False,
trainable=False,
bits: int = 4,
disable_exllama=False,
**kwargs
):
"""
Replace all LlamaAttention modules with QuantLlamaAttention modules, fusing the q, k, v projections.
"""
QuantLinear = dynamically_import_QuantLinear(use_triton=use_triton, desc_act=desc_act, group_size=group_size, bits=bits, disable_exllama=disable_exllama)
for name, m in model.named_modules():
if not isinstance(m, LlamaAttention):
continue
q_proj = m.q_proj
k_proj = m.k_proj
v_proj = m.v_proj
if QuantLinear.QUANT_TYPE == "exllama" and desc_act:
# TODO: support it. The issue lies maybe in the line:
# int groups = qzeros.size(0);
# in exllama_ext.cpp
raise ValueError("Exllama kernel does not support query/key/value fusion with act-order. Please either use inject_fused_attention=False or disable_exllama=True.")
elif m.num_heads == m.num_key_value_heads:
qweights = torch.cat([q_proj.qweight, k_proj.qweight, v_proj.qweight], dim=1)
qzeros = torch.cat([q_proj.qzeros, k_proj.qzeros, v_proj.qzeros], dim=1)
scales = torch.cat([q_proj.scales, k_proj.scales, v_proj.scales], dim=1)
if QuantLinear.QUANT_TYPE == "exllama":
g_idx = None
else:
g_idx = torch.cat([q_proj.g_idx, k_proj.g_idx, v_proj.g_idx], dim=0)
bias = torch.cat([q_proj.bias, k_proj.bias, v_proj.bias], dim=0) if q_proj.bias is not None else None
qlinear_args = (
q_proj.bits,
q_proj.group_size,
q_proj.infeatures,
q_proj.outfeatures + k_proj.outfeatures + v_proj.outfeatures,
True if q_proj.bias is not None else False,
)
qlinear_kwargs = {"trainable": trainable}
if (not desc_act or group_size == -1) and not use_triton:
qlinear_kwargs["use_cuda_fp16"] = use_cuda_fp16
qkv_layer = QuantLinear(*qlinear_args, **qlinear_kwargs)
qkv_layer.qweight = qweights
qkv_layer.qzeros = qzeros
qkv_layer.scales = scales
qkv_layer.g_idx = g_idx
qkv_layer.bias = bias
qkv_layers = [qkv_layer]
else:
qweights = torch.cat([k_proj.qweight, v_proj.qweight], dim=1)
qzeros = torch.cat([k_proj.qzeros, v_proj.qzeros], dim=1)
scales = torch.cat([k_proj.scales, v_proj.scales], dim=1)
if QuantLinear.QUANT_TYPE == "exllama":
g_idx = None
else:
g_idx = torch.cat([k_proj.g_idx, v_proj.g_idx], dim=0)
bias = torch.cat([k_proj.bias, v_proj.bias], dim=0) if q_proj.bias is not None else None
qlinear_args = (
k_proj.bits,
k_proj.group_size,
k_proj.infeatures,
k_proj.outfeatures + v_proj.outfeatures,
True if q_proj.bias is not None else False,
)
qlinear_kwargs = {"trainable": trainable}
if (not desc_act or group_size == -1) and not use_triton:
qlinear_kwargs["use_cuda_fp16"] = use_cuda_fp16
kv_layer = QuantLinear(*qlinear_args, **qlinear_kwargs)
kv_layer.qweight = qweights
kv_layer.qzeros = qzeros
kv_layer.scales = scales
kv_layer.g_idx = g_idx
kv_layer.bias = bias
qkv_layers = [q_proj, kv_layer]
attn = cls(m.config, qkv_layers, m.o_proj, m.rotary_emb)
if '.' in name:
parent_name = name.rsplit('.', 1)[0]
child_name = name[len(parent_name) + 1:]
parent = model.get_submodule(parent_name)
else:
parent_name = ''
parent = model
child_name = name
setattr(parent, child_name, attn)