hf_text-generation-inference/server/text_generation_server/layers/marlin.py

287 lines
8.1 KiB
Python

from dataclasses import dataclass
from typing import Optional, Tuple, List
import torch
import torch.nn as nn
from text_generation_server.utils.import_utils import SYSTEM
try:
import marlin_kernels
except ImportError:
marlin_kernels = None
try:
major, _minor = torch.cuda.get_device_capability()
has_sm_8_0 = major >= 8
except Exception:
has_sm_8_0 = False
GPTQ_MARLIN_BITS = [4, 8]
GPTQ_MARLIN_GROUP_SIZES = [-1, 32, 64, 128]
MARLIN_TILE_SIZE = 16
def _check_marlin_kernels():
if not (SYSTEM == "cuda" and has_sm_8_0):
raise NotImplementedError(
"Using quantized Marlin models requires a GPU with CUDA capability 8.0 or later."
)
if marlin_kernels is None:
raise NotImplementedError(
"marlin is not installed, install it with: pip install server/marlin"
)
def _check_valid_shape(in_features: int, out_features: int):
if (in_features % 128 != 0 or out_features % 64 != 0) and (
in_features % 64 != 0 or out_features % 128 != 0
):
raise ValueError(
f"The GPTQ Marlin kernel does not have a valid thread configuration for weight matrix with shape ({out_features}, {in_features})."
" The shape elements must be divisible by (128, 64) or (64, 128)."
)
# https://github.com/IST-DASLab/marlin/blob/2f6d7c10e124b3c5fa29ff8d77d568bd7af3274c/marlin/__init__.py#L40C1-L68C54
def _get_perms() -> Tuple[List[int], List[int]]:
scale_perm = []
for i in range(8):
scale_perm.extend([i + 8 * j for j in range(8)])
scale_perm_single = []
for i in range(4):
scale_perm_single.extend([2 * i + j for j in [0, 1, 8, 9, 16, 17, 24, 25]])
return scale_perm, scale_perm_single
_scale_perm, _scale_perm_single = _get_perms()
def permute_scales(scales: torch.Tensor):
out_features = scales.shape[1]
if scales.shape[0] == 1:
scales = scales.reshape((-1, len(_scale_perm_single)))[:, _scale_perm_single]
else:
scales = scales.reshape((-1, len(_scale_perm)))[:, _scale_perm]
return scales.reshape((-1, out_features)).contiguous()
@dataclass
class GPTQMarlinWeight:
"""
Repacked GPTQ Marlin weights.
"""
qweight: torch.Tensor
scales: torch.Tensor
g_idx: torch.Tensor
perm: torch.Tensor
bits: int
is_full_k: bool
def __post_init__(self):
assert self.qweight.dtype == torch.int32
assert self.scales.dtype == torch.float16
assert self.g_idx.dtype == torch.int32
assert self.perm.dtype == torch.int32
def repack_gptq_for_marlin(
*,
qweight: torch.Tensor,
scales: torch.Tensor,
g_idx: torch.Tensor,
bits: int,
desc_act: bool,
groupsize: int,
sym: bool,
sharded_infeatures: bool,
) -> GPTQMarlinWeight:
"""Convert GPTQ weights to a layout that's compatible with GPTQ-Marlin kernels."""
_check_marlin_kernels()
assert marlin_kernels is not None
if bits not in GPTQ_MARLIN_BITS:
supported_bits = ", ".join(str(b) for b in GPTQ_MARLIN_BITS)
raise RuntimeError(
f"Repacking {bits}-bit GPTQ weights as Marlin is not supported, must be one of: {supported_bits}"
)
if groupsize not in GPTQ_MARLIN_GROUP_SIZES:
supported_sizes = ", ".join(str(b) for b in GPTQ_MARLIN_GROUP_SIZES)
raise RuntimeError(
f"Repacking GPTQ weights with group size {groupsize} as Marlin is not supported, must be one of: {supported_sizes}"
)
if not sym:
raise RuntimeError(
"Repacking GPTQ weights with asymmetric quantization as Marlin is not supported."
)
weights_per_int = 32 // bits
in_features = qweight.shape[0] * weights_per_int
out_features = qweight.shape[1]
if in_features % groupsize != 0:
raise ValueError(
f"Number of input features ({in_features}) not divisible by group size ({groupsize})"
)
if desc_act and groupsize != -1:
perm = torch.argsort(g_idx).to(torch.int)
g_idx = g_idx[perm]
else:
perm = torch.empty(0, dtype=torch.int, device=qweight.device)
g_idx = torch.empty(0, dtype=torch.int, device=qweight.device)
repacked = marlin_kernels.gptq_marlin_repack(
qweight, perm, in_features, out_features, bits
)
scales = permute_scales(scales)
is_full_k = not (desc_act and sharded_infeatures)
return GPTQMarlinWeight(
qweight=repacked,
scales=scales,
g_idx=g_idx,
perm=perm,
bits=bits,
is_full_k=is_full_k,
)
class GPTQMarlinLinear(nn.Module):
"""
Linear layer for GPTQ weights that were converted for the GPTQ-Marlin
kernels.
"""
def __init__(
self,
*,
weight: GPTQMarlinWeight,
bias: Optional[torch.Tensor],
):
super().__init__()
_check_marlin_kernels()
assert marlin_kernels is not None
in_features = weight.qweight.shape[0] * MARLIN_TILE_SIZE
out_features = weight.scales.shape[1]
_check_valid_shape(in_features=in_features, out_features=out_features)
self.bits = weight.bits
self.is_full_k = weight.is_full_k
self.register_buffer("qweight", weight.qweight)
self.register_buffer("scales", weight.scales)
self.register_buffer("g_idx", weight.g_idx)
self.register_buffer("perm", weight.perm)
if bias is not None:
self.register_buffer("bias", bias)
else:
self.bias = None
self.workspace = torch.zeros(
out_features // 64 * 16, dtype=torch.int, device=weight.qweight.device
)
def forward(self, A: torch.Tensor) -> torch.Tensor:
assert marlin_kernels is not None
A_flat = A.view(-1, A.shape[-1])
C = marlin_kernels.gptq_marlin_gemm(
A_flat,
self.qweight,
self.scales,
self.g_idx,
self.perm,
self.workspace,
self.bits,
A_flat.shape[0],
self.scales.shape[1],
A_flat.shape[1],
self.is_full_k,
)
C = C.reshape(A.shape[:-1] + (self.scales.shape[1],))
if self.bias is not None:
C += self.bias
return C
@dataclass
class MarlinWeight:
"""
Marlin weights.
Attributes:
B (torch.Tensor): int4-quantized weights packed into int32.
s (torch.Tensor): float16 scales.
"""
B: torch.Tensor
s: torch.Tensor
def __post_init__(self):
assert self.B.dtype == torch.int32
assert self.s.dtype == torch.float16
class MarlinLinear(nn.Module):
def __init__(self, *, weight: MarlinWeight, bias: Optional[torch.Tensor]):
super().__init__()
_check_marlin_kernels()
assert marlin_kernels is not None
in_features = weight.B.shape[0] * MARLIN_TILE_SIZE
out_features = weight.s.shape[1]
assert (
in_features % 128 == 0
), f"Number of input features ({in_features}) not divisable by 128"
assert (
out_features % 256 == 0
), f"Number of output features ({out_features}) not divisable by 256"
groupsize = -1 if weight.s.shape[0] == 1 else in_features // weight.s.shape[0]
assert groupsize in {
-1,
128,
}, f"Group size must be -1 or 128, was {groupsize}"
self.register_buffer("B", weight.B)
self.register_buffer("s", weight.s)
if bias is not None:
self.register_buffer("bias", bias)
else:
self.bias = None
self.workspace = torch.zeros(
out_features // 64 * 16, dtype=torch.int, device=weight.B.device
)
def forward(self, A: torch.Tensor) -> torch.Tensor:
assert marlin_kernels is not None
C = marlin_kernels.marlin_gemm(
A.view(-1, A.shape[-1]),
self.B,
self.s,
self.workspace,
A.shape[0],
self.s.shape[1],
A.shape[1],
)
C = C.reshape(A.shape[:-1] + (self.s.shape[1],))
if self.bias is not None:
C += self.bias
return C