337 lines
12 KiB
Python

from typing import Any, Dict, List, Optional
import torch
from torch.nn.parameter import Parameter
from vllm import _custom_ops as ops
from vllm.logger import init_logger
from vllm.model_executor.layers.linear import (LinearBase, LinearMethodBase,
set_weight_attrs)
from vllm.model_executor.layers.quantization.base_config import (
QuantizationConfig)
from vllm.model_executor.layers.quantization.utils.marlin_utils import (
apply_gptq_marlin_linear, check_marlin_supported, marlin_is_k_full,
marlin_make_empty_g_idx, marlin_make_workspace, marlin_permute_scales,
marlin_repeat_scales_on_all_ranks, marlin_sort_g_idx, replace_tensor,
verify_marlin_supported, verify_marlin_supports_shape)
from vllm.model_executor.layers.vocab_parallel_embedding import ParallelLMHead
from vllm.scalar_type import scalar_types
logger = init_logger(__name__)
class GPTQMarlinConfig(QuantizationConfig):
"""Config class for GPTQ Marlin"""
# (num_bits, is_sym) -> quant_type
TYPE_MAP = {
(4, True): scalar_types.uint4b8,
(8, True): scalar_types.uint8b128,
}
def __init__(self, weight_bits: int, group_size: int, desc_act: bool,
is_sym: bool, lm_head_quantized: bool) -> None:
if desc_act and group_size == -1:
# In this case, act_order == True is the same as act_order == False
# (since we have only one group per output channel)
desc_act = False
self.pack_factor = 32 // weight_bits # packed into int32
self.group_size = group_size
self.desc_act = desc_act
self.lm_head_quantized = lm_head_quantized
if (weight_bits, is_sym) not in self.TYPE_MAP:
raise ValueError("Unsupported quantization config: "
f"bits={weight_bits}, sym={is_sym}")
self.quant_type = self.TYPE_MAP[(weight_bits, is_sym)]
# Verify supported on platform.
verify_marlin_supported(quant_type=self.quant_type,
group_size=self.group_size)
def __repr__(self) -> str:
return (f"GPTQMarlinConfig(quant_type={self.quant_type}, "
f"group_size={self.group_size}, "
f"desc_act={self.desc_act}, "
f"lm_head_quantized={self.lm_head_quantized})")
@classmethod
def get_name(cls) -> str:
return "gptq_marlin"
@classmethod
def get_supported_act_dtypes(cls) -> List[torch.dtype]:
return [torch.half, torch.bfloat16]
@classmethod
def get_min_capability(cls) -> int:
return 80
@classmethod
def get_config_filenames(cls) -> List[str]:
return ["quantize_config.json"]
@classmethod
def from_config(cls, config: Dict[str, Any]) -> "GPTQMarlinConfig":
weight_bits = cls.get_from_keys(config, ["bits"])
group_size = cls.get_from_keys(config, ["group_size"])
desc_act = cls.get_from_keys(config, ["desc_act"])
is_sym = cls.get_from_keys(config, ["sym"])
lm_head_quantized = cls.get_from_keys_or(config, ["lm_head"],
default=False)
return cls(weight_bits, group_size, desc_act, is_sym,
lm_head_quantized)
@classmethod
def override_quantization_method(cls, hf_quant_cfg,
user_quant) -> Optional[str]:
can_convert = cls.is_gptq_marlin_compatible(hf_quant_cfg)
is_valid_user_quant = (user_quant is None or user_quant == "marlin"
or user_quant == "gptq_marlin")
if can_convert and is_valid_user_quant:
msg = ("The model is convertible to {} during runtime."
" Using {} kernel.".format(cls.get_name(), cls.get_name()))
logger.info(msg)
return cls.get_name()
if can_convert and user_quant == "gptq":
logger.info("Detected that the model can run with gptq_marlin"
", however you specified quantization=gptq explicitly,"
" so forcing gptq. Use quantization=gptq_marlin for"
" faster inference")
return None
def get_quant_method(self, layer: torch.nn.Module,
prefix: str) -> Optional["GPTQMarlinLinearMethod"]:
if (isinstance(layer, LinearBase) or
(isinstance(layer, ParallelLMHead) and self.lm_head_quantized)):
return GPTQMarlinLinearMethod(self)
return None
def get_scaled_act_names(self) -> List[str]:
return []
@classmethod
def is_gptq_marlin_compatible(cls, quant_config: Dict[str, Any]):
# Extract data from quant config.
quant_method = quant_config.get("quant_method", "").lower()
num_bits = quant_config.get("bits", None)
group_size = quant_config.get("group_size", None)
sym = quant_config.get("sym", None)
desc_act = quant_config.get("desc_act", None)
if quant_method != "gptq":
return False
# If we cannot find the info needed in the config, cannot convert.
if (num_bits is None or group_size is None or sym is None
or desc_act is None):
return False
if (num_bits, sym) not in cls.TYPE_MAP:
return False
return check_marlin_supported(quant_type=cls.TYPE_MAP[(num_bits, sym)],
group_size=group_size,
min_capability=cls.get_min_capability())
class GPTQMarlinLinearMethod(LinearMethodBase):
"""Linear method for GPTQ Marlin.
Args:
quant_config: The GPTQ Marlin quantization config.
"""
def __init__(self, quant_config: GPTQMarlinConfig) -> None:
self.quant_config = quant_config
def create_weights(
self,
layer: torch.nn.Module,
input_size_per_partition: int,
output_partition_sizes: List[int],
input_size: int,
output_size: int,
params_dtype: torch.dtype,
**extra_weight_attrs,
) -> None:
del output_size
output_size_per_partition = sum(output_partition_sizes)
is_row_parallel = input_size != input_size_per_partition
# Normalize group_size
if self.quant_config.group_size != -1:
group_size = self.quant_config.group_size
else:
group_size = input_size
verify_marlin_supports_shape(
output_size_per_partition=output_size_per_partition,
input_size_per_partition=input_size_per_partition,
input_size=input_size,
group_size=group_size)
# Determine sharding
if marlin_repeat_scales_on_all_ranks(self.quant_config.desc_act,
self.quant_config.group_size,
is_row_parallel):
# By setting scale_dim == None, weight_loader will
# repeat the scales on each GPU in TP>1 case.
scales_and_zp_input_dim = None
scales_and_zp_size = input_size // group_size
else:
# By setting scale_dim == 0, weight_loader will
# shard the scales in TP>1 case.
scales_and_zp_input_dim = 0
scales_and_zp_size = input_size_per_partition // group_size
# Quantized weights
qweight = Parameter(
torch.empty(
input_size_per_partition // self.quant_config.pack_factor,
output_size_per_partition,
dtype=torch.int32,
),
requires_grad=False,
)
set_weight_attrs(
qweight,
{
**extra_weight_attrs,
"input_dim": 0,
"output_dim": 1,
"packed_dim": 0,
"pack_factor": self.quant_config.pack_factor,
},
)
# Activation order
g_idx = Parameter(
torch.empty(
input_size_per_partition,
dtype=torch.int32,
),
requires_grad=False,
)
# Ignore warning from fused linear layers such as QKVParallelLinear.
set_weight_attrs(
g_idx,
{
**extra_weight_attrs, "input_dim": 0,
"ignore_warning": True
},
)
# Scales
scales = Parameter(
torch.empty(
scales_and_zp_size,
output_size_per_partition,
dtype=params_dtype,
),
requires_grad=False,
)
set_weight_attrs(
scales,
{
**extra_weight_attrs,
"input_dim": scales_and_zp_input_dim,
"output_dim": 1,
},
)
# Quantized zero-points
qzeros = Parameter(
torch.empty(
scales_and_zp_size,
output_size_per_partition // self.quant_config.pack_factor,
dtype=torch.int32,
),
requires_grad=False,
)
set_weight_attrs(
qzeros,
{
**extra_weight_attrs,
"input_dim": scales_and_zp_input_dim,
"output_dim": 1,
"packed_dim": 1,
"pack_factor": self.quant_config.pack_factor,
},
)
layer.register_parameter("qweight", qweight)
layer.register_parameter("g_idx", g_idx)
layer.register_parameter("scales", scales)
layer.register_parameter("qzeros", qzeros)
layer.input_size_per_partition = input_size_per_partition
layer.output_size_per_partition = output_size_per_partition
layer.input_size = input_size
layer.is_k_full = marlin_is_k_full(self.quant_config.desc_act,
is_row_parallel)
# Checkpoints are serialized in AutoGPTQ format, which is different from the
# marlin format. This function is called after the weights are loaded.
# Here, we handle the repacking, including the activation reordering case.
def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
device = layer.qweight.device
# Allocate marlin workspace
layer.workspace = marlin_make_workspace(
layer.output_size_per_partition, device)
# Handle sorting for activation reordering if needed.
if self.quant_config.desc_act:
g_idx, g_idx_sort_indices = marlin_sort_g_idx(layer.g_idx)
layer.g_idx_sort_indices = g_idx_sort_indices
replace_tensor(layer, "g_idx", g_idx)
else:
layer.g_idx = marlin_make_empty_g_idx(device)
layer.g_idx_sort_indices = marlin_make_empty_g_idx(device)
# No zero-point
layer.zp = marlin_make_empty_g_idx(device)
# Repack weights from autogptq format to marlin format.
marlin_qweight = ops.gptq_marlin_repack(
layer.qweight,
perm=layer.g_idx_sort_indices,
size_k=layer.input_size_per_partition,
size_n=layer.output_size_per_partition,
num_bits=self.quant_config.quant_type.size_bits)
replace_tensor(layer, "qweight", marlin_qweight)
# Permute scales from autogptq format to marlin format.
marlin_scales = marlin_permute_scales(
layer.scales,
size_k=(layer.input_size if self.quant_config.desc_act else
layer.input_size_per_partition),
size_n=layer.output_size_per_partition,
group_size=self.quant_config.group_size)
replace_tensor(layer, "scales", marlin_scales)
def apply(
self,
layer: torch.nn.Module,
x: torch.Tensor,
bias: Optional[torch.Tensor] = None,
) -> torch.Tensor:
return apply_gptq_marlin_linear(
input=x,
weight=layer.qweight,
weight_scale=layer.scales,
weight_zp=layer.zp,
g_idx=layer.g_idx,
g_idx_sort_indices=layer.g_idx_sort_indices,
workspace=layer.workspace,
wtype=self.quant_config.quant_type,
output_size_per_partition=layer.output_size_per_partition,
input_size_per_partition=layer.input_size_per_partition,
is_k_full=layer.is_k_full,
bias=bias)