feat(core): add AutoFP8 quantization classes

- add AutoFP8 quantization classes
- minor fixes based on IDE recommendations
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BuildTools 2024-09-01 20:35:35 -07:00
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commit 81b2d4137b
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5 changed files with 573 additions and 14 deletions

560
src/AutoFP8.py Normal file
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@ -0,0 +1,560 @@
import copy
import gc
import re
from typing import List
from typing import Optional, Tuple
import torch
import tqdm
from transformers import AutoModelForCausalLM, AutoTokenizer
from Logger import Logger
# https://github.com/neuralmagic/AutoFP8
class BaseQuantizeConfig:
"""Configuration for model quantization.
Args:
quant_method: Type/precision of quantization method to use.
At the moment, this is just "fp8" which specifically means
the fp8_e4m3 format in pytorch.
activation_scheme: Choice of either "dynamic" or "static" quantization
of activtions. If "static", then calibration samples are required
during quantization to produce accurate per-tensor scales for
activations of Linear modules.
ignore_patterns: List of patterns used to ignore layers. If a string
starts with "re:", then everything afterward is used as python
regex style matching i.e. re.search(), for each Linear layer.
By default, "re:.*lm_head" is included to ignore the embedding
Linear layer usually at the end of decoder LLMs
kv_cache_quant_targets: Tuple of Linear module names to target for
calibration of the output scales for KV cache quantization.
Usually, these should be `("k_proj", "v_proj")`.
"""
def __init__(
self,
quant_method: str = "fp8",
activation_scheme: str = "static",
ignore_patterns: List[str] = ["re:.*lm_head"],
kv_cache_quant_targets: Optional[Tuple[str]] = None,
):
if quant_method != "fp8":
raise ValueError("Only FP8 quantization is supported.")
if activation_scheme not in ["static", "dynamic"]:
raise ValueError(
"Invalid activation_scheme. Choose either 'static' or 'dynamic'."
)
self.quant_method = quant_method
self.activation_scheme = activation_scheme
self.ignore_patterns = ignore_patterns
self.kv_cache_quant_targets = kv_cache_quant_targets
self.ignored_layers = []
# Class responsible for quantizing weights
class FP8DynamicLinear(torch.nn.Module):
def __init__(
self,
weight: torch.Tensor,
weight_scale: torch.Tensor,
bias: torch.nn.Parameter,
):
super().__init__()
self.weight = torch.nn.Parameter(weight, requires_grad=False)
self.weight_scale = torch.nn.Parameter(weight_scale, requires_grad=False)
self.bias = bias
def forward(self, x):
qinput, x_scale = per_tensor_quantize(x)
output = fp8_gemm(
A=qinput,
A_scale=x_scale,
B=self.weight,
B_scale=self.weight_scale,
bias=self.bias,
out_dtype=x.dtype,
)
return output
# Module responsible for taking already quantized weights, and recording input scales (and possibly output scales)
# using an activation observer
class FP8StaticLinearQuantizer(torch.nn.Module):
def __init__(
self,
weight: torch.Tensor,
weight_scale: torch.Tensor,
bias: torch.nn.Parameter,
quantize_output: bool = False,
):
super().__init__()
self.weight = torch.nn.Parameter(weight, requires_grad=False)
self.weight_scale = torch.nn.Parameter(weight_scale, requires_grad=False)
self.bias = bias
self.input_scale = None
self.output_scale = None
self.quantize_output = quantize_output
def forward(self, x):
qinput, x_input_scale = per_tensor_quantize(x)
if self.input_scale is None:
self.input_scale = torch.nn.Parameter(x_input_scale, requires_grad=False)
elif x_input_scale > self.input_scale:
self.input_scale = torch.nn.Parameter(x_input_scale, requires_grad=False)
output = fp8_gemm(
A=qinput,
A_scale=self.input_scale,
B=self.weight,
B_scale=self.weight_scale,
bias=self.bias,
out_dtype=x.dtype,
)
# Optionally, quantize output and record scale
if self.quantize_output:
qoutput, output_scale = per_tensor_quantize(output)
if self.output_scale is None:
self.output_scale = torch.nn.Parameter(
output_scale, requires_grad=False
)
elif output_scale > self.output_scale:
self.output_scale = torch.nn.Parameter(
output_scale, requires_grad=False
)
output = qoutput.to(output.dtype) * output_scale
return output
# Module responsible for representing the final checkpoint representation
class FP8StaticLinear(torch.nn.Module):
def __init__(
self,
weight: torch.nn.Parameter,
weight_scale: torch.nn.Parameter,
bias: torch.nn.Parameter,
input_scale: torch.nn.Parameter,
output_scale: Optional[torch.nn.Parameter] = None,
):
super().__init__()
self.weight = weight
self.weight_scale = weight_scale
self.bias = bias
self.input_scale = input_scale
self.output_scale = output_scale
def forward(self, x):
qinput = static_per_tensor_quantize(x, self.input_scale)
output = fp8_gemm(
A=qinput,
A_scale=self.input_scale,
B=self.weight,
B_scale=self.weight_scale,
bias=self.bias,
out_dtype=x.dtype,
)
if self.output_scale:
qoutput = static_per_tensor_quantize(output, self.output_scale)
output = qoutput.to(output.dtype) * self.output_scale
return output
class AutoFP8ForCausalLM:
def __init__(
self,
model: AutoModelForCausalLM,
quantize_config: BaseQuantizeConfig,
):
self.model = model
self.model_type = self.model.config.model_type
self.config = self.model.config
# Gather the Linear module names that we want to ignore
quantize_config.ignored_layers = get_layers_to_ignore(
self.model, quantize_config.ignore_patterns
)
if quantize_config.kv_cache_quant_targets:
kv_cache_quant_layers = get_kv_cache_quant_layers(
self.model, quantize_config.kv_cache_quant_targets
)
if len(kv_cache_quant_layers) == 0:
raise ValueError(
f"Could not find any kv cache layers using kv_cache_quant_targets={quantize_config.kv_cache_quant_targets}, please fix your argument."
)
quantize_config.kv_cache_quant_layers = kv_cache_quant_layers
self.quantize_config = quantize_config
@classmethod
def from_pretrained(
cls,
pretrained_model_name_or_path: str,
quantize_config: BaseQuantizeConfig,
**model_init_kwargs,
):
"""Load the un-quantized pretrained model"""
def skip(*args, **kwargs):
pass
torch.nn.init.kaiming_uniform_ = skip
torch.nn.init.uniform_ = skip
torch.nn.init.normal_ = skip
# Parameters related to loading from Hugging Face Hub
cache_dir = model_init_kwargs.pop("cache_dir", None)
force_download = model_init_kwargs.pop("force_download", False)
resume_download = model_init_kwargs.pop("resume_download", False)
proxies = model_init_kwargs.pop("proxies", None)
local_files_only = model_init_kwargs.pop("local_files_only", False)
use_auth_token = model_init_kwargs.pop("use_auth_token", None)
revision = model_init_kwargs.pop("revision", None)
subfolder = model_init_kwargs.pop("subfolder", "")
commit_hash = model_init_kwargs.pop("_commit_hash", None)
cached_file_kwargs = {
"cache_dir": cache_dir,
"force_download": force_download,
"proxies": proxies,
"resume_download": resume_download,
"local_files_only": local_files_only,
"use_auth_token": use_auth_token,
"revision": revision,
"subfolder": subfolder,
"_commit_hash": commit_hash,
}
torch.cuda.empty_cache()
# Important defaults
if "torch_dtype" not in model_init_kwargs:
model_init_kwargs["torch_dtype"] = "auto"
if "device_map" not in model_init_kwargs:
model_init_kwargs["device_map"] = "auto"
merged_kwargs = {**model_init_kwargs, **cached_file_kwargs}
print("Loading model with the following kwargs:", merged_kwargs)
model = AutoModelForCausalLM.from_pretrained(
pretrained_model_name_or_path, **merged_kwargs
)
model_config = model.config.to_dict()
seq_len_keys = ["max_position_embeddings", "seq_length", "n_positions"]
if any(k in model_config for k in seq_len_keys):
for key in seq_len_keys:
if key in model_config:
model.seqlen = model_config[key]
break
else:
print("Can't get model's sequence length, setting to 2048.")
model.seqlen = 2048
model.eval()
return cls(model, quantize_config)
def quantize(self, calibration_tokens: Optional[torch.Tensor] = None):
# Always quantize the weights as they do not require calibration data
quantize_weights(self.model, self.quantize_config)
if self.quantize_config.activation_scheme == "static":
assert (
calibration_tokens is not None
), "Calibration tokens required for activation quantization"
def _prepare_calibration_data(calibration_tokens):
if hasattr(calibration_tokens, "input_ids"):
return calibration_tokens.input_ids
return calibration_tokens
quantize_activations(
self.model,
self.quantize_config,
_prepare_calibration_data(calibration_tokens),
)
def save_quantized(self, save_dir, logger):
save_quantized_model(
self.model,
quant_config=self.quantize_config,
save_dir=save_dir,
logger=logger,
)
def cleanup_memory():
gc.collect()
torch.cuda.empty_cache()
def per_tensor_quantize(tensor: torch.Tensor) -> Tuple[torch.Tensor, float]:
"""Quantize a tensor using per-tensor static scaling factor.
Args:
tensor: The input tensor.
"""
finfo = torch.finfo(torch.float8_e4m3fn)
# Calculate the scale as dtype max divided by absmax.
# Since .abs() creates a new tensor, we use aminmax to get
# the min and max first and then calculate the absmax.
if tensor.numel() == 0:
# Deal with empty tensors (triggered by empty MoE experts)
min_val, max_val = (
torch.tensor(-16.0, dtype=tensor.dtype),
torch.tensor(16.0, dtype=tensor.dtype),
)
else:
min_val, max_val = tensor.aminmax()
amax = torch.maximum(min_val.abs(), max_val.abs())
scale = finfo.max / amax.clamp(min=1e-12)
# Scale and clamp the tensor to bring it to
# the representative range of float8 data type
# (as default cast is unsaturated)
qweight = (tensor * scale).clamp(min=finfo.min, max=finfo.max)
# Return both float8 data and the inverse scale (as float),
# as both required as inputs to torch._scaled_mm
qweight = qweight.to(torch.float8_e4m3fn)
scale = scale.float().reciprocal()
return qweight, scale
def static_per_tensor_quantize(tensor: torch.Tensor, inv_scale: float) -> torch.Tensor:
finfo = torch.finfo(torch.float8_e4m3fn)
qweight = (tensor / inv_scale).clamp(min=finfo.min, max=finfo.max)
return qweight.to(torch.float8_e4m3fn)
def fp8_gemm(A, A_scale, B, B_scale, bias, out_dtype):
if A.numel() == 0:
# Deal with empty tensors (triggeted by empty MoE experts)
return torch.empty(size=(0, B.shape[0]), dtype=out_dtype, device=A.device)
# TODO: Disable native fp8 gemm for now, always just dequantize
# native_fp8_support = (
# torch.cuda.is_available() and torch.cuda.get_device_capability() >= (8, 9)
# )
native_fp8_support = False
if native_fp8_support:
need_reshape = A.dim() == 3
if need_reshape:
batch_size = A.shape[0]
A_input = A.reshape(-1, A.shape[-1])
else:
batch_size = None
A_input = A
output, _ = torch._scaled_mm(
A_input,
B.t(),
out_dtype=out_dtype,
scale_a=A_scale,
scale_b=B_scale,
bias=bias,
)
if need_reshape:
output = output.reshape(
batch_size, output.shape[0] // batch_size, output.shape[1]
)
else:
output = torch.nn.functional.linear(
A.to(out_dtype) * A_scale,
B.to(out_dtype) * B_scale.to(out_dtype),
bias=bias,
)
return output
def replace_module(model: AutoModelForCausalLM, name: str, new_module: torch.nn.Module):
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, new_module)
def quantize_weights(
model: AutoModelForCausalLM,
quantize_config: BaseQuantizeConfig,
):
named_modules = list(model.named_modules())
for name, linear in tqdm.tqdm(named_modules, desc="Quantizing weights"):
if (
not isinstance(linear, torch.nn.Linear)
or name in quantize_config.ignored_layers
):
continue
quant_weight, weight_scale = per_tensor_quantize(linear.weight)
bias = copy.deepcopy(linear.bias) if linear.bias is not None else None
quant_linear = FP8DynamicLinear(
weight=quant_weight, weight_scale=weight_scale, bias=bias
)
replace_module(model, name, quant_linear)
del linear.weight
del linear.bias
del linear
cleanup_memory()
def quantize_activations(
model: AutoModelForCausalLM,
quantize_config: BaseQuantizeConfig,
calibration_tokens,
):
# Replace weight quantizer with a dynamic activation quantizer observer
for name, dynamic_quant_linear in model.named_modules():
if (
not isinstance(dynamic_quant_linear, FP8DynamicLinear)
or name in quantize_config.ignored_layers
):
continue
quantizer = FP8StaticLinearQuantizer(
weight=dynamic_quant_linear.weight,
weight_scale=dynamic_quant_linear.weight_scale,
bias=dynamic_quant_linear.bias,
quantize_output=(
hasattr(quantize_config, "kv_cache_quant_layers")
and name in quantize_config.kv_cache_quant_layers
),
)
replace_module(model, name, quantizer)
del dynamic_quant_linear
cleanup_memory()
# Pass through calibration data to measure activation scales
with torch.inference_mode():
with tqdm.tqdm(
total=calibration_tokens.shape[0], desc="Calibrating activation scales"
) as pbar:
for row_idx in range(calibration_tokens.shape[0]):
model(calibration_tokens[row_idx].reshape(1, -1))
cleanup_memory()
pbar.update(1)
# Replace dynamic quantizer observer with StaticLinear for export
for name, quantizer in model.named_modules():
if (
not isinstance(quantizer, FP8StaticLinearQuantizer)
or name in quantize_config.ignored_layers
):
continue
static_proj = FP8StaticLinear(
weight=quantizer.weight,
weight_scale=quantizer.weight_scale,
bias=quantizer.bias,
input_scale=quantizer.input_scale,
output_scale=quantizer.output_scale,
)
replace_module(model, name, static_proj)
del quantizer
cleanup_memory()
# Post-process step for kv cache scales to take the k/v module
# `output_scale` parameters, and store them in the parent attention
# module as `k_scale` and `v_scale`
if hasattr(quantize_config, "kv_cache_quant_layers"):
# Assumes that list is ordered such that [layer0.k_proj, layer0.v_proj, layer1.k_proj, layer1.v_proj, ...]
# so we make a list of tuples [(layer0.k_proj, layer0.v_proj), (layer1.k_proj, layer1.v_proj), ...]
kv_proj_pairs = zip(*[iter(quantize_config.kv_cache_quant_layers)] * 2)
for k_proj_name, v_proj_name in kv_proj_pairs:
parent_module_name = ".".join(k_proj_name.split(".")[:-1])
assert parent_module_name == ".".join(v_proj_name.split(".")[:-1])
parent_module = dict(model.named_modules())[parent_module_name]
k_proj = dict(model.named_modules())[k_proj_name]
v_proj = dict(model.named_modules())[v_proj_name]
parent_module.k_scale = torch.nn.Parameter(
k_proj.output_scale, requires_grad=False
)
parent_module.v_scale = torch.nn.Parameter(
v_proj.output_scale, requires_grad=False
)
# Remove output_scale from k_proj and v_proj
k_proj.output_scale = None
v_proj.output_scale = None
cleanup_memory()
def save_quantized_model(
model: AutoModelForCausalLM,
quant_config: BaseQuantizeConfig,
save_dir: str,
logger: Logger,
):
logger.info(model)
logger.info(f"Saving the model to {save_dir}")
static_q_dict = {
"quantization_config": {
"quant_method": "fp8",
"activation_scheme": quant_config.activation_scheme,
"ignored_layers": quant_config.ignored_layers,
}
}
if hasattr(quant_config, "kv_cache_quant_layers"):
static_q_dict["quantization_config"]["kv_cache_scheme"] = "static"
model.config.update(static_q_dict)
model.save_pretrained(save_dir)
tokenizer = AutoTokenizer.from_pretrained(model.config._name_or_path)
tokenizer.save_pretrained(save_dir)
def get_layers_to_ignore(model, ignore_patterns) -> List[str]:
ignored_layers = set()
for name, linear in model.named_modules():
if not isinstance(linear, torch.nn.Linear):
continue
for ignore_pattern in ignore_patterns:
regex_prefix = "re:"
if ignore_pattern.startswith(regex_prefix):
# check if name matches regex and add to set if true
regex_pattern = ignore_pattern[len(regex_prefix) :]
if re.search(regex_pattern, name):
ignored_layers.add(name)
else:
# else, exact match
if ignore_pattern == name:
ignored_layers.add(name)
return list(ignored_layers)
def get_kv_cache_quant_layers(model, kv_cache_quant_targets: Tuple[str]) -> List[str]:
kv_cache_quant_layers = []
for name, linear in model.named_modules():
if not isinstance(linear, torch.nn.Linear):
continue
for output_quant_target in kv_cache_quant_targets:
if name.endswith(output_quant_target):
kv_cache_quant_layers.append(name)
return kv_cache_quant_layers
def quantize_to_fp8_dynamic(
input_model_dir: str, output_model_dir: str, logger: Logger
) -> None:
logger.info("Starting fp8 dynamic quantization")
# Define quantization config with static activation scales
quantize_config = BaseQuantizeConfig(
quant_method="fp8", activation_scheme="dynamic"
)
# Load the model, quantize, and save checkpoint
model = AutoFP8ForCausalLM.from_pretrained(input_model_dir, quantize_config)
# No examples for dynamic quantization
model.quantize([])
model.save_quantized(output_model_dir, logger)

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@ -35,9 +35,8 @@ class AutoGGUF(QMainWindow):
def __init__(self, args: List[str]) -> None:
super().__init__()
self.logger = Logger("AutoGGUF", "logs")
width, height = self.parse_resolution()
self.logger = Logger("AutoGGUF", "logs")
self.logger.info(INITIALIZING_AUTOGGUF)
self.setWindowTitle(WINDOW_TITLE)
@ -107,7 +106,7 @@ def __init__(self, args: List[str]) -> None:
self.update_gpu_offload_slider = partial(
ui_update.update_gpu_offload_slider, self
)
self.update_model_info = partial(ui_update.update_model_info, self.logger, self)
self.update_model_info = partial(ui_update.update_model_info, self.logger)
self.update_system_info = partial(ui_update.update_system_info, self)
self.update_download_progress = partial(
ui_update.update_download_progress, self
@ -792,6 +791,8 @@ def __init__(self, args: List[str]) -> None:
default_theme = f.read()
self.setStyleSheet(default_theme)
self.imported_models = []
# Load models
self.load_models()
@ -1089,7 +1090,7 @@ def restart_task(self, task_item) -> None:
self.quant_threads.append(new_thread)
new_thread.status_signal.connect(task_item.update_status)
new_thread.finished_signal.connect(
lambda: self.task_finished(new_thread)
lambda: self.task_finished(new_thread, task_item)
)
new_thread.error_signal.connect(
lambda err: handle_error(self.logger, err, task_item)
@ -1173,7 +1174,7 @@ def verify_gguf(self, file_path) -> bool:
with open(file_path, "rb") as f:
magic = f.read(4)
return magic == b"GGUF"
except Exception:
except (FileNotFoundError, IOError, OSError):
return False
def load_models(self) -> None:
@ -1454,7 +1455,7 @@ def quantize_model(self) -> None:
def parse_progress(self, line, task_item) -> None:
# Parses the output line for progress information and updates the task item.
match = re.search(r"\[\s*(\d+)\s*/\s*(\d+)\s*\].*", line)
match = re.search(r"\[\s*(\d+)\s*/\s*(\d+)\s*].*", line)
if match:
current = int(match.group(1))
total = int(match.group(2))
@ -1516,8 +1517,6 @@ def import_model(self) -> None:
QMessageBox.StandardButton.No,
)
if reply == QMessageBox.StandardButton.Yes:
if not hasattr(self, "imported_models"):
self.imported_models = []
self.imported_models.append(file_path)
self.load_models()
self.logger.info(MODEL_IMPORTED_SUCCESSFULLY.format(file_name))
@ -1596,7 +1595,9 @@ def generate_imatrix(self) -> None:
self.task_list.setItemWidget(list_item, task_item)
thread.status_signal.connect(task_item.update_status)
thread.finished_signal.connect(lambda: self.task_finished(thread))
thread.finished_signal.connect(
lambda: self.task_finished(thread, task_item)
)
thread.error_signal.connect(
lambda err: handle_error(self.logger, err, task_item)
)

View File

@ -61,7 +61,6 @@ def get_override_string(
"{system.hostname}": lambda: socket.gethostname(),
"{system.platform}": lambda: platform.system(),
"{system.python.version}": lambda: platform.python_version(),
"{system.time.milliseconds}": lambda: str(int(time.time() * 1000)),
"{system.date}": lambda: datetime.now().strftime("%Y-%m-%d"),
"{model.name}": lambda: (
model_name if model_name is not None else "Unknown Model"

View File

@ -419,7 +419,7 @@ def prepare_tensors(self):
shape_str = f"{{{', '.join(str(n) for n in reversed(shape))}}}"
logger.info(
f"{f'%-{max_name_len}s' % f'{new_name},'} {old_dtype} --> {data_qtype.name}, shape = {shape_str}"
f"{f'%s-{max_name_len}s' % f'{new_name},'} {old_dtype} --> {data_qtype.name}, shape = {shape_str}"
)
self.gguf_writer.add_tensor(new_name, data, raw_dtype=data_qtype)
@ -1132,7 +1132,6 @@ def set_vocab(self):
try:
self._set_vocab_gpt2()
except Exception:
self._set_vocab_sentencepiece()
self.gguf_writer.add_add_bos_token(False)
self.gguf_writer.add_pad_token_id(3)
@ -4125,7 +4124,7 @@ def set_vocab(self):
if len(token) == 1:
continue
merged = ChatGLMModel.bpe(mergeable_ranks, token, max_rank=rank)
assert len(merged) >= 2 and len(merged) <= 7
assert 2 <= len(merged) <= 7
merges.append(" ".join(map(ChatGLMModel.token_bytes_to_string, merged)))
added_vocab = tokenizer.get_added_vocab()

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@ -12,7 +12,7 @@ def toggle_gpu_offload_auto(self, state) -> None:
self.gpu_offload_spinbox.setEnabled(not is_auto)
def update_model_info(logger, self, model_info) -> None:
def update_model_info(logger, model_info) -> None:
logger.debug(UPDATING_MODEL_INFO.format(model_info))
pass