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

680 lines
20 KiB
Python

from dataclasses import dataclass
from typing import List, Optional, Tuple, Union
import torch
import torch.nn as nn
from loguru import logger
from text_generation_server.layers.fp8 import fp8_quantize
from text_generation_server.utils.import_utils import SYSTEM
from text_generation_server.utils.log import log_once
from text_generation_server.utils.weights import Weight, Weights, WeightsLoader
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
class MarlinWeightsLoader(WeightsLoader):
"""Loader for Marlin-quantized weights."""
def __init__(self, *, bits: int, is_marlin_24: bool):
self.bits = bits
self.is_marlin_24 = is_marlin_24
def get_weights(self, weights: "Weights", prefix: str):
"""
Get weights at the given prefix and apply without tensor paralllism.
"""
is_marlin_24 = getattr(self, "gptq_checkpoint_format", None) == "marlin_24"
if is_marlin_24:
try:
B = weights.get_tensor(f"{prefix}.B_24")
except RuntimeError:
raise RuntimeError(
"Cannot load `marlin` 2:4 sparsity weight, make sure the model is already quantized."
)
B_meta = weights.get_tensor(f"{prefix}.B_meta")
s = weights.get_tensor(f"{prefix}.s")
weight = GPTQMarlin24Weight(B=B, B_meta=B_meta, s=s, bits=self.bits)
else:
try:
B = weights.get_tensor(f"{prefix}.B")
except RuntimeError:
raise RuntimeError(
"Cannot load `marlin` weight, make sure the model is already quantized."
)
s = weights.get_tensor(f"{prefix}.s")
weight = MarlinWeight(B=B, s=s)
return weight
def get_weights_col_packed(
self,
weights: Weights,
prefix: str,
block_sizes: Union[int, List[int]],
):
if self.is_marlin_24:
B = weights.get_packed_sharded(
f"{prefix}.B_24", dim=1, block_sizes=block_sizes
)
B_meta = weights.get_packed_sharded(
f"{prefix}.B_meta", dim=1, block_sizes=block_sizes
)
s = weights.get_packed_sharded(
f"{prefix}.s", dim=1, block_sizes=block_sizes
)
weight = GPTQMarlin24Weight(B=B, B_meta=B_meta, s=s, bits=self.bits)
else:
B = weights.get_packed_sharded(
f"{prefix}.B", dim=1, block_sizes=block_sizes
)
s = weights.get_packed_sharded(
f"{prefix}.s", dim=1, block_sizes=block_sizes
)
weight = MarlinWeight(B=B, s=s)
return weight
def get_multi_weights_col(self, weights: Weights, prefixes: List[str], dim: int):
if self.is_marlin_24:
try:
B = torch.cat(
[weights.get_sharded(f"{p}.B_24", dim=1) for p in prefixes], dim=1
)
except RuntimeError:
raise RuntimeError(
f"Cannot load `marlin` weight, make sure the model is already quantized"
)
B_meta = torch.cat(
[weights.get_sharded(f"{p}.B_meta", dim=1) for p in prefixes], dim=1
)
s = torch.cat(
[weights.get_sharded(f"{p}.s", dim=1) for p in prefixes], dim=1
)
weight = GPTQMarlin24Weight(B=B, B_meta=B_meta, s=s, bits=self.bits)
else:
try:
B = torch.cat(
[weights.get_sharded(f"{p}.B", dim=1) for p in prefixes], dim=1
)
except RuntimeError:
raise RuntimeError(
f"Cannot load `marlin` weight, make sure the model is already quantized"
)
s = torch.cat(
[weights.get_sharded(f"{p}.s", dim=1) for p in prefixes], dim=1
)
weight = MarlinWeight(B=B, s=s)
return weight
def get_weights_row(self, weights: Weights, prefix: str):
if self.is_marlin_24:
try:
B = weights.get_sharded(f"{prefix}.B_24", dim=0)
except RuntimeError:
raise RuntimeError(
"Cannot load `marlin` 2:4 sparsity weight, make sure the model is already quantized."
)
B_meta = weights.get_sharded(f"{prefix}.B_meta", dim=0)
num_groups = weights._get_slice(f"{prefix}.s").get_shape()[0]
if num_groups == 1:
# The number of groups is 1 when groupsize == -1. share
# scales between all shards in this case.
s = weights.get_tensor(f"{prefix}.s")
else:
s = weights.get_sharded(f"{prefix}.s", dim=0)
weight = GPTQMarlin24Weight(B=B, B_meta=B_meta, s=s, bits=self.bits)
else:
try:
B = weights.get_sharded(f"{prefix}.B", dim=0)
except RuntimeError:
raise RuntimeError(
"Cannot load `marlin` weight, make sure the model is already quantized."
)
num_groups = weights._get_slice(f"{prefix}.s").get_shape()[0]
if num_groups == 1:
# The number of groups is 1 when groupsize == -1. share
# scales between all shards in this case.
s = weights.get_tensor(f"{prefix}.s")
else:
s = weights.get_sharded(f"{prefix}.s", dim=0)
weight = MarlinWeight(B=B, s=s)
return weight
def can_use_gptq_marlin(
*, bits: int, groupsize: int, quant_method: str, quantize: str, sym: bool
) -> bool:
return (
SYSTEM == "cuda"
and marlin_kernels is not None
and has_sm_8_0
and quantize == "gptq"
and quant_method == "gptq"
and bits in GPTQ_MARLIN_BITS
and groupsize in GPTQ_MARLIN_GROUP_SIZES
and sym
)
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(Weight):
"""
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 get_linear(self, bias: torch.Tensor):
return GPTQMarlinLinear(
weight=self,
bias=bias,
)
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.qweight = weight.qweight
self.scales = weight.scales
self.g_idx = weight.g_idx
self.perm = weight.perm
if bias is not None:
self.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
GPTQ_MARLIN_24_MIN_THREAD_N = 128
GPTQ_MARLIN_24_MIN_THREAD_K = 128
GPTQ_MARLIN_24_MAX_PARALLEL = 64
GPTQ_MARLIN_24_SUPPORTED_NUM_BITS = [4, 8]
GPTQ_MARLIN_24_SUPPORTED_GROUP_SIZES = [-1, 128]
@dataclass
class GPTQMarlin24Weight:
"""
GPTQ-Marlin 2:4 weights.
Attributes:
B (torch.Tensor): int4-quantized weights packed into int32.
B_meta (torch.Tensor): metadata for 2:4 sparsity.
s (torch.Tensor): float16 scales.
bits: quantized weight size.
"""
B: torch.Tensor
B_meta: torch.Tensor
s: torch.Tensor
bits: int
def __post_init__(self):
assert self.B.dtype == torch.int32
assert self.B_meta.dtype == torch.int16
assert self.s.dtype == torch.float16
def get_linear(self, bias: torch.Tensor):
return GPTQMarlin24Linear(
weight=self,
bias=bias,
)
class GPTQMarlin24Linear(nn.Module):
def __init__(self, *, weight: GPTQMarlin24Weight, bias: Optional[torch.Tensor]):
super().__init__()
_check_marlin_kernels()
assert marlin_kernels is not None
if weight.bits not in GPTQ_MARLIN_BITS:
supported_bits = ", ".join(str(b) for b in GPTQ_MARLIN_BITS)
raise RuntimeError(
f"{weight.bits}-bit GPTQ Sparse 2:4 Marlin is not supported, must be one of: {supported_bits}"
)
in_features = weight.B.shape[0] * MARLIN_TILE_SIZE * 2
out_features = weight.s.shape[1]
groupsize = -1 if weight.s.shape[0] == 1 else in_features // weight.s.shape[0]
if groupsize not in GPTQ_MARLIN_24_SUPPORTED_GROUP_SIZES:
supported_sizes = ", ".join(
str(b) for b in GPTQ_MARLIN_24_SUPPORTED_GROUP_SIZES
)
raise RuntimeError(
f"Group size {groupsize} is not supported, must be one of: {supported_sizes}"
)
self.bits = weight.bits
weights_per_int32 = 32 // self.bits
assert (
out_features % GPTQ_MARLIN_24_MIN_THREAD_N == 0
), f"Number of output features ({out_features}) not divisable by {GPTQ_MARLIN_24_MIN_THREAD_N} threads"
assert (
out_features % weights_per_int32 == 0
), f"Number of output features ({out_features}) not divisable by weights per int32 ({weights_per_int32})"
assert (
in_features % GPTQ_MARLIN_24_MIN_THREAD_K == 0
), f"Number of output features ({out_features}) not divisable by {GPTQ_MARLIN_24_MIN_THREAD_K} threads"
if groupsize != -1 and in_features % groupsize != 0:
raise ValueError(
f"Number of input features ({in_features}) not divisable by group size ({groupsize})"
)
self.B = weight.B
self.B_meta = weight.B_meta
self.s = weight.s
if bias is not None:
self.bias = bias
else:
self.bias = None
self.workspace = torch.zeros(
(out_features // GPTQ_MARLIN_24_MIN_THREAD_N) * GPTQ_MARLIN_24_MAX_PARALLEL,
dtype=torch.int,
device=weight.B.device,
)
def forward(self, A: torch.Tensor) -> torch.Tensor:
assert marlin_kernels is not None
C = marlin_kernels.gptq_marlin_24_gemm(
A.view(-1, A.shape[-1]),
self.B,
self.B_meta,
self.s,
self.workspace,
self.bits,
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
class GPTQMarlinFP8Linear(nn.Module):
"""
FP8 GPTQ-Marlin linear layer.
"""
def __init__(
self,
weight: torch.Tensor,
bias: Optional[torch.Tensor],
) -> None:
super().__init__()
_check_marlin_kernels()
assert marlin_kernels is not None
log_once(logger.info, "GPU does not support FP8, using Marlin FP8 kernel")
qweight, scale = fp8_quantize(weight)
scale = scale.to(torch.float16)
qweight, scales = repack_fp8_for_marlin(qweight, scale)
in_features = qweight.shape[0] * MARLIN_TILE_SIZE
out_features = scales.shape[1]
_check_valid_shape(in_features=in_features, out_features=out_features)
self.qweight = qweight
self.scales = scales
self.bias = bias if bias is not None else None
self.workspace = torch.zeros(
out_features // 64 * 16, dtype=torch.int, device=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.fp8_marlin_gemm(
A_flat,
self.qweight,
self.scales,
self.workspace,
8,
A_flat.shape[0],
self.scales.shape[1],
A_flat.shape[1],
)
C = C.reshape(A.shape[:-1] + (self.scales.shape[1],))
if self.bias is not None:
C += self.bias
return C
def pack_fp8_as_int32(fp8_tensor: torch.Tensor) -> torch.Tensor:
"""
Repack FP8 weights to gptq format (packed int32 elements).
"""
assert fp8_tensor.dtype == torch.float8_e4m3fn
if fp8_tensor.shape[0] % 4 != 0:
raise ValueError(
f"Leading tensor dimension is not divisable by 4: {fp8_tensor.shape[0]}"
)
# Reshape to prepare for packing
reshaped = fp8_tensor.reshape(-1, 4, *fp8_tensor.shape[1:])
# Convert fp8 to uint8 (byte) representation
byte_tensor = reshaped.view(torch.uint8)
# Pack 4 uint8 values into one int32
packed = torch.zeros(
fp8_tensor.shape[0] // 4,
fp8_tensor.shape[1],
dtype=torch.int32,
device=fp8_tensor.device,
)
for i in range(4):
packed.bitwise_or_(byte_tensor[:, i].to(torch.int32) << i * 8)
return packed
def repack_fp8_for_marlin(weight: torch.Tensor, scale: torch.Tensor):
"""
Repack FP8 tensor for GPTQ-Marlin.
"""
out_features, in_features = weight.shape
# Torch linear layers weights with shape [out_features, in_features],
# GPTQ-quantized weights use [in_feateres/pack_factor, in_features],
# so transpose before packing.
qweight = pack_fp8_as_int32(weight.t())
perm = torch.empty(0, dtype=torch.int, device=qweight.device)
repacked = marlin_kernels.gptq_marlin_repack(
qweight, perm, in_features, out_features, 8
)
scales = scale.reshape(1, 1).repeat(1, out_features)
scales = permute_scales(scales)
return repacked, scales
@dataclass
class MarlinWeight(Weight):
"""
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
def get_linear(self, bias: torch.Tensor):
return MarlinLinear(weight=self, bias=bias)
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.B = weight.B
self.s = weight.s
if bias is not None:
self.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