Spaces:
Sleeping
Sleeping
File size: 5,817 Bytes
ca1ecab |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 |
from typing import Any, Dict, List, Optional
import torch
from torch.nn.parameter import Parameter
from vllm._C import ops
from vllm.model_executor.layers.linear import (LinearMethodBase,
set_weight_attrs)
from vllm.model_executor.layers.quantization.base_config import QuantizationConfig
class AWQConfig(QuantizationConfig):
"""Config class for AWQ.
Reference: https://arxiv.org/abs/2306.00978
"""
def __init__(
self,
weight_bits: int,
group_size: int,
zero_point: bool,
) -> None:
self.weight_bits = weight_bits
self.group_size = group_size
self.zero_point = zero_point
if self.weight_bits != 4:
raise ValueError(
"Currently, only 4-bit weight quantization is supported for "
f"AWQ, but got {self.weight_bits} bits.")
self.pack_factor = 32 // self.weight_bits
def __repr__(self) -> str:
return (f"AWQConfig(weight_bits={self.weight_bits}, "
f"group_size={self.group_size}, "
f"zero_point={self.zero_point})")
def get_name(self) -> str:
return "awq"
def get_supported_act_dtypes(self) -> List[torch.dtype]:
return [torch.half]
def get_min_capability(self) -> int:
# The AWQ kernel only supports Turing or newer GPUs.
return 75
@staticmethod
def get_config_filenames() -> List[str]:
return [
"quant_config.json", # E.g., casperhansen/vicuna-7b-v1.5-awq
"quantize_config.json", # E.g., abhinavkulkarni/mosaicml-mpt-7b-instruct-w4-g128-awq
]
@classmethod
def from_config(cls, config: Dict[str, Any]) -> "AWQConfig":
weight_bits = cls.get_from_keys(config, ["w_bit", "bits"])
group_size = cls.get_from_keys(config, ["q_group_size", "group_size"])
zero_point = cls.get_from_keys(config, ["zero_point"])
return cls(weight_bits, group_size, zero_point)
def get_linear_method(self) -> "AWQLinearMethod":
return AWQLinearMethod(self)
def get_scaled_act_names(self) -> List[str]:
return ["gelu", "gelu_fast", "gelu_new", "gelu_pytorch_tanh"]
class AWQLinearMethod(LinearMethodBase):
"""Linear method for AWQ.
Args:
quant_config: The AWQ quantization config.
"""
def __init__(self, quant_config: AWQConfig):
self.quant_config = quant_config
def create_weights(self, input_size_per_partition: int,
output_size_per_partition: int, input_size: int,
output_size: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
if input_size_per_partition % self.quant_config.group_size != 0:
raise ValueError(
"The input size is not aligned with the quantized "
"weight shape. This can be caused by too large "
"tensor parallel size.")
if output_size_per_partition % self.quant_config.pack_factor != 0:
raise ValueError(
"The output size is not aligned with the quantized "
"weight shape. This can be caused by too large "
"tensor parallel size.")
qweight = Parameter(
torch.empty(
input_size_per_partition,
output_size_per_partition // self.quant_config.pack_factor,
device="cuda",
dtype=torch.int32,
),
requires_grad=False,
)
set_weight_attrs(
qweight, {
"input_dim": 0,
"output_dim": 1,
"packed_dim": 1,
"pack_factor": self.quant_config.pack_factor,
})
qzeros = Parameter(
torch.empty(
input_size_per_partition // self.quant_config.group_size,
output_size_per_partition // self.quant_config.pack_factor,
device="cuda",
dtype=torch.int32,
),
requires_grad=False,
)
set_weight_attrs(
qzeros, {
"input_dim": 0,
"output_dim": 1,
"packed_dim": 1,
"pack_factor": self.quant_config.pack_factor,
})
scales = Parameter(
torch.empty(
input_size_per_partition // self.quant_config.group_size,
output_size_per_partition,
device="cuda",
dtype=params_dtype,
),
requires_grad=False,
)
set_weight_attrs(scales, {
"input_dim": 0,
"output_dim": 1,
})
return {
"qweight": qweight,
"qzeros": qzeros,
"scales": scales,
}
def apply_weights(self,
weights: Dict[str, Any],
x: torch.Tensor,
bias: Optional[torch.Tensor] = None) -> torch.Tensor:
qweight = weights["qweight"]
qzeros = weights["qzeros"]
scales = weights["scales"]
pack_factor = self.quant_config.pack_factor
out_shape = (x.shape[:-1] + (qweight.shape[-1] * pack_factor, ))
reshaped_x = x.reshape(-1, x.shape[-1])
# num_tokens >= threshold
FP16_MATMUL_HEURISTIC_CONDITION = x.shape[:-1].numel() >= 256
if FP16_MATMUL_HEURISTIC_CONDITION:
out = ops.awq_dequantize(qweight, scales, qzeros, 0, 0, 0)
out = torch.matmul(reshaped_x, out)
else:
out = ops.awq_gemm(reshaped_x, qweight, scales, qzeros,
pack_factor)
if bias is not None:
out = out + bias
return out.reshape(out_shape)
|