ComfyUI/comfy/ops.py
rattus 783782d5d7
Implement block prefetch + Lora Async load + and adopt in LTX (Speedup!) (CORE-111) (#13618)
* mm: Use Aimdo raw allocator for cast buffers

pytorch manages allocation of growing buffers on streams poorly. Pyt
has no windows support for the expandable segments allocator (which is
the right tool for this job), while also segmenting the memory by
stream such that it can be generally re-used. So kick the problem to
aimdo which can just grow a virtual region thats freed per stream.

* plan

* ops: move cpu handler up to the caller

* ops: split up prefetch from weight prep block prefetching API

Split up the casting and weight formating/lora stuff in prep for
arbitrary prefetch support.

* ops: implement block prefetching API

allow a model to construct a prefetch list and operate it for increased
async offload.

* ltxv2: Implement block prefetching

* Implement lora async offload

Implement async offload of loras.
2026-05-02 19:23:24 -04:00

1288 lines
55 KiB
Python

"""
This file is part of ComfyUI.
Copyright (C) 2024 Stability AI
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
"""
import torch
import logging
import comfy.model_management
from comfy.cli_args import args, PerformanceFeature
import comfy.float
import json
import comfy.memory_management
import comfy.pinned_memory
import comfy.utils
import comfy_aimdo.model_vbar
import comfy_aimdo.torch
def run_every_op():
if torch.compiler.is_compiling():
return
comfy.model_management.throw_exception_if_processing_interrupted()
def scaled_dot_product_attention(q, k, v, *args, **kwargs):
return torch.nn.functional.scaled_dot_product_attention(q, k, v, *args, **kwargs)
try:
if torch.cuda.is_available() and comfy.model_management.WINDOWS:
from torch.nn.attention import SDPBackend, sdpa_kernel
import inspect
if "set_priority" in inspect.signature(sdpa_kernel).parameters:
SDPA_BACKEND_PRIORITY = [
SDPBackend.FLASH_ATTENTION,
SDPBackend.EFFICIENT_ATTENTION,
SDPBackend.MATH,
]
SDPA_BACKEND_PRIORITY.insert(0, SDPBackend.CUDNN_ATTENTION)
def scaled_dot_product_attention(q, k, v, *args, **kwargs):
if q.nelement() < 1024 * 128: # arbitrary number, for small inputs cudnn attention seems slower
return torch.nn.functional.scaled_dot_product_attention(q, k, v, *args, **kwargs)
with sdpa_kernel(SDPA_BACKEND_PRIORITY, set_priority=True):
return torch.nn.functional.scaled_dot_product_attention(q, k, v, *args, **kwargs)
else:
logging.warning("Torch version too old to set sdpa backend priority.")
except (ModuleNotFoundError, TypeError):
logging.warning("Could not set sdpa backend priority.")
NVIDIA_MEMORY_CONV_BUG_WORKAROUND = False
try:
if comfy.model_management.is_nvidia():
cudnn_version = torch.backends.cudnn.version()
if (cudnn_version >= 91002 and cudnn_version < 91500) and comfy.model_management.torch_version_numeric >= (2, 9) and comfy.model_management.torch_version_numeric <= (2, 10):
#TODO: change upper bound version once it's fixed'
NVIDIA_MEMORY_CONV_BUG_WORKAROUND = True
logging.info("working around nvidia conv3d memory bug.")
except:
pass
cast_to = comfy.model_management.cast_to #TODO: remove once no more references
def cast_to_input(weight, input, non_blocking=False, copy=True):
return comfy.model_management.cast_to(weight, input.dtype, input.device, non_blocking=non_blocking, copy=copy)
def materialize_meta_param(s, param_keys):
for param_key in param_keys:
param = getattr(s, param_key, None)
if param is not None and getattr(param, "is_meta", False):
setattr(s, param_key, torch.nn.Parameter(torch.zeros(param.shape, dtype=param.dtype), requires_grad=param.requires_grad))
# FIXME: add n=1 cache hit fast path
def cast_modules_with_vbar(comfy_modules, dtype, device, bias_dtype, non_blocking):
offload_stream = None
cast_buffer = None
cast_buffer_offset = 0
def ensure_offload_stream(module, required_size, check_largest):
nonlocal offload_stream
nonlocal cast_buffer
if offload_stream is None:
offload_stream = comfy.model_management.get_offload_stream(device)
if offload_stream is None or not check_largest or len(comfy_modules) != 1:
return
current_size = 0 if cast_buffer is None else cast_buffer.size()
if current_size < required_size and module is comfy.model_management.LARGEST_AIMDO_CASTED_WEIGHT[0]:
offload_stream = comfy.model_management.get_offload_stream(device)
cast_buffer = None
if required_size > comfy.model_management.LARGEST_AIMDO_CASTED_WEIGHT[1]:
comfy.model_management.LARGEST_AIMDO_CASTED_WEIGHT = (module, required_size)
def get_cast_buffer(buffer_size):
nonlocal offload_stream
nonlocal cast_buffer
nonlocal cast_buffer_offset
if buffer_size == 0:
return None
if offload_stream is None:
return torch.empty((buffer_size,), dtype=torch.uint8, device=device)
cast_buffer = comfy.model_management.get_aimdo_cast_buffer(offload_stream, device)
buffer = comfy_aimdo.torch.aimdo_to_tensor(cast_buffer.get(buffer_size, cast_buffer_offset), device)
cast_buffer_offset += buffer_size
return buffer
for s in comfy_modules:
signature = comfy_aimdo.model_vbar.vbar_fault(s._v)
resident = comfy_aimdo.model_vbar.vbar_signature_compare(signature, s._v_signature)
prefetch = {
"signature": signature,
"resident": resident,
}
if resident:
s._prefetch = prefetch
continue
materialize_meta_param(s, ["weight", "bias"])
xfer_dest = comfy_aimdo.torch.aimdo_to_tensor(s._v, device) if signature is not None else None
cast_geometry = comfy.memory_management.tensors_to_geometries([ s.weight, s.bias ])
cast_dest = None
needs_cast = False
xfer_source = [ s.weight, s.bias ]
pin = comfy.pinned_memory.get_pin(s)
if pin is not None:
xfer_source = [ pin ]
for data, geometry in zip([ s.weight, s.bias ], cast_geometry):
if data is None:
continue
if data.dtype != geometry.dtype:
needs_cast = True
cast_dest = xfer_dest
xfer_dest = None
break
dest_size = comfy.memory_management.vram_aligned_size(xfer_source)
ensure_offload_stream(s, dest_size if xfer_dest is None else 0, True)
if xfer_dest is None:
xfer_dest = get_cast_buffer(dest_size)
if signature is None and pin is None:
comfy.pinned_memory.pin_memory(s)
pin = comfy.pinned_memory.get_pin(s)
else:
pin = None
if pin is not None:
comfy.model_management.cast_to_gathered(xfer_source, pin)
xfer_source = [ pin ]
#send it over
comfy.model_management.cast_to_gathered(xfer_source, xfer_dest, non_blocking=non_blocking, stream=offload_stream)
for param_key in ("weight", "bias"):
lowvram_fn = getattr(s, param_key + "_lowvram_function", None)
if lowvram_fn is not None:
ensure_offload_stream(s, cast_buffer_offset, False)
lowvram_fn.prepare(lambda size: get_cast_buffer(size), offload_stream)
prefetch["xfer_dest"] = xfer_dest
prefetch["cast_dest"] = cast_dest
prefetch["cast_geometry"] = cast_geometry
prefetch["needs_cast"] = needs_cast
s._prefetch = prefetch
return offload_stream
def resolve_cast_module_with_vbar(s, dtype, device, bias_dtype, compute_dtype, want_requant):
prefetch = getattr(s, "_prefetch", None)
if prefetch["resident"]:
weight = s._v_weight
bias = s._v_bias
else:
xfer_dest = prefetch["xfer_dest"]
if prefetch["needs_cast"]:
cast_dest = prefetch["cast_dest"] if prefetch["cast_dest"] is not None else torch.empty((comfy.memory_management.vram_aligned_size(prefetch["cast_geometry"]),), dtype=torch.uint8, device=device)
for pre_cast, post_cast in zip(comfy.memory_management.interpret_gathered_like([s.weight, s.bias ], xfer_dest),
comfy.memory_management.interpret_gathered_like(prefetch["cast_geometry"], cast_dest)):
if post_cast is not None:
post_cast.copy_(pre_cast)
xfer_dest = cast_dest
params = comfy.memory_management.interpret_gathered_like(prefetch["cast_geometry"], xfer_dest)
weight = params[0]
bias = params[1]
if prefetch["signature"] is not None:
s._v_weight = weight
s._v_bias = bias
s._v_signature = prefetch["signature"]
def post_cast(s, param_key, x, dtype, resident, update_weight):
lowvram_fn = getattr(s, param_key + "_lowvram_function", None)
fns = getattr(s, param_key + "_function", [])
if x is None:
return None
orig = x
def to_dequant(tensor, dtype):
tensor = tensor.to(dtype=dtype)
if isinstance(tensor, QuantizedTensor):
tensor = tensor.dequantize()
return tensor
if orig.dtype != dtype or len(fns) > 0:
x = to_dequant(x, dtype)
if not resident and lowvram_fn is not None:
x = to_dequant(x, dtype if compute_dtype is None else compute_dtype)
x = lowvram_fn(x)
if (want_requant and len(fns) == 0 or update_weight):
seed = comfy.utils.string_to_seed(s.seed_key)
if isinstance(orig, QuantizedTensor):
y = QuantizedTensor.from_float(x, s.layout_type, scale="recalculate", stochastic_rounding=seed)
else:
y = comfy.float.stochastic_rounding(x, orig.dtype, seed=seed)
if want_requant and len(fns) == 0:
x = y
if update_weight:
orig.copy_(y)
for f in fns:
x = f(x)
return x
update_weight = prefetch["signature"] is not None
weight = post_cast(s, "weight", weight, dtype, prefetch["resident"], update_weight)
if bias is not None:
bias = post_cast(s, "bias", bias, bias_dtype, prefetch["resident"], update_weight)
return weight, bias
def cast_bias_weight(s, input=None, dtype=None, device=None, bias_dtype=None, offloadable=False, compute_dtype=None, want_requant=False):
# NOTE: offloadable=False is a a legacy and if you are a custom node author reading this please pass
# offloadable=True and call uncast_bias_weight() after your last usage of the weight/bias. This
# will add async-offload support to your cast and improve performance.
if input is not None:
if dtype is None:
if isinstance(input, QuantizedTensor):
dtype = input.params.orig_dtype
else:
dtype = input.dtype
if bias_dtype is None:
bias_dtype = dtype
if device is None:
device = input.device
def format_return(result, offloadable):
weight, bias, offload_stream = result
return (weight, bias, offload_stream) if offloadable else (weight, bias)
non_blocking = comfy.model_management.device_supports_non_blocking(device)
if hasattr(s, "_v"):
#vbar doesn't support CPU weights, but some custom nodes have weird paths
#that might switch the layer to the CPU and expect it to work. We have to take
#a clone conservatively as we are mmapped and some SFT files are packed misaligned
#If you are a custom node author reading this, please move your layer to the GPU
#or declare your ModelPatcher as CPU in the first place.
if comfy.model_management.is_device_cpu(device):
materialize_meta_param(s, ["weight", "bias"])
weight = s.weight.to(dtype=dtype, copy=True)
if isinstance(weight, QuantizedTensor):
weight = weight.dequantize()
bias = s.bias.to(dtype=bias_dtype, copy=True) if s.bias is not None else None
return format_return((weight, bias, (None, None, None)), offloadable)
prefetched = hasattr(s, "_prefetch")
offload_stream = None
offload_device = None
if not prefetched:
offload_stream = cast_modules_with_vbar([s], dtype, device, bias_dtype, non_blocking)
comfy.model_management.sync_stream(device, offload_stream)
weight, bias = resolve_cast_module_with_vbar(s, dtype, device, bias_dtype, compute_dtype, want_requant)
if not prefetched:
if getattr(s, "_prefetch")["signature"] is not None:
offload_device = device
for param_key in ("weight", "bias"):
lowvram_fn = getattr(s, param_key + "_lowvram_function", None)
if lowvram_fn is not None:
lowvram_fn.clear_prepared()
delattr(s, "_prefetch")
return format_return((weight, bias, (offload_stream, offload_device, None)), offloadable)
if offloadable and (device != s.weight.device or
(s.bias is not None and device != s.bias.device)):
offload_stream = comfy.model_management.get_offload_stream(device)
else:
offload_stream = None
bias = None
weight = None
if offload_stream is not None and not args.cuda_malloc:
cast_buffer_size = comfy.memory_management.vram_aligned_size([ s.weight, s.bias ])
cast_buffer = comfy.model_management.get_cast_buffer(offload_stream, device, cast_buffer_size, s)
#The streams can be uneven in buffer capability and reject us. Retry to get the other stream
if cast_buffer is None:
offload_stream = comfy.model_management.get_offload_stream(device)
cast_buffer = comfy.model_management.get_cast_buffer(offload_stream, device, cast_buffer_size, s)
params = comfy.memory_management.interpret_gathered_like([ s.weight, s.bias ], cast_buffer)
weight = params[0]
bias = params[1]
weight_has_function = len(s.weight_function) > 0
bias_has_function = len(s.bias_function) > 0
weight = comfy.model_management.cast_to(s.weight, None, device, non_blocking=non_blocking, copy=weight_has_function, stream=offload_stream, r=weight)
if s.bias is not None:
bias = comfy.model_management.cast_to(s.bias, None, device, non_blocking=non_blocking, copy=bias_has_function, stream=offload_stream, r=bias)
comfy.model_management.sync_stream(device, offload_stream)
bias_a = bias
weight_a = weight
if s.bias is not None:
bias = bias.to(dtype=bias_dtype)
for f in s.bias_function:
bias = f(bias)
if weight_has_function or weight.dtype != dtype:
weight = weight.to(dtype=dtype)
if isinstance(weight, QuantizedTensor):
weight = weight.dequantize()
for f in s.weight_function:
weight = f(weight)
return format_return((weight, bias, (offload_stream, weight_a, bias_a)), offloadable)
def uncast_bias_weight(s, weight, bias, offload_stream):
if offload_stream is None:
return
os, weight_a, bias_a = offload_stream
device=None
#FIXME: This is really bad RTTI
if weight_a is not None and not isinstance(weight_a, torch.Tensor):
comfy_aimdo.model_vbar.vbar_unpin(s._v)
device = weight_a
if os is None:
return
if device is None:
if weight_a is not None:
device = weight_a.device
else:
if bias_a is None:
return
device = bias_a.device
os.wait_stream(comfy.model_management.current_stream(device))
class CastWeightBiasOp:
comfy_cast_weights = False
weight_function = []
bias_function = []
class disable_weight_init:
@staticmethod
def _zero_init_parameter(module, name):
param = getattr(module, name)
device = None if getattr(param, "is_meta", False) else param.device
setattr(module, name, torch.nn.Parameter(torch.zeros(param.shape, device=device, dtype=param.dtype), requires_grad=False))
@staticmethod
def _lazy_load_from_state_dict(module, state_dict, prefix, local_metadata,
missing_keys, unexpected_keys, weight_shape,
bias_shape=None):
assign_to_params_buffers = local_metadata.get("assign_to_params_buffers", False)
prefix_len = len(prefix)
for k, v in state_dict.items():
key = k[prefix_len:]
if key == "weight":
if not assign_to_params_buffers:
v = v.clone()
module.weight = torch.nn.Parameter(v, requires_grad=False)
elif bias_shape is not None and key == "bias" and v is not None:
if not assign_to_params_buffers:
v = v.clone()
module.bias = torch.nn.Parameter(v, requires_grad=False)
else:
unexpected_keys.append(k)
if module.weight is None:
module.weight = torch.nn.Parameter(torch.zeros(weight_shape), requires_grad=False)
missing_keys.append(prefix + "weight")
if bias_shape is not None and module.bias is None and getattr(module, "comfy_need_lazy_init_bias", False):
module.bias = torch.nn.Parameter(torch.zeros(bias_shape), requires_grad=False)
missing_keys.append(prefix + "bias")
class Linear(torch.nn.Linear, CastWeightBiasOp):
def __init__(self, in_features, out_features, bias=True, device=None, dtype=None):
# don't trust subclasses that BYO state dict loader to call us.
if (not comfy.model_management.WINDOWS
or not comfy.memory_management.aimdo_enabled
or type(self)._load_from_state_dict is not disable_weight_init.Linear._load_from_state_dict):
super().__init__(in_features, out_features, bias, device, dtype)
return
# Issue is with `torch.empty` still reserving the full memory for the layer.
# Windows doesn't over-commit memory so without this, We are momentarily commit
# charged for the weight even though we might zero-copy it when we load the
# state dict. If the commit charge exceeds the ceiling we can destabilize the
# system.
torch.nn.Module.__init__(self)
self.in_features = in_features
self.out_features = out_features
self.weight = None
self.bias = None
self.comfy_need_lazy_init_bias=bias
self.weight_comfy_model_dtype = dtype
self.bias_comfy_model_dtype = dtype
def _load_from_state_dict(self, state_dict, prefix, local_metadata,
strict, missing_keys, unexpected_keys, error_msgs):
if (not comfy.model_management.WINDOWS
or not comfy.memory_management.aimdo_enabled
or type(self)._load_from_state_dict is not disable_weight_init.Linear._load_from_state_dict):
return super()._load_from_state_dict(state_dict, prefix, local_metadata, strict,
missing_keys, unexpected_keys, error_msgs)
disable_weight_init._lazy_load_from_state_dict(
self,
state_dict,
prefix,
local_metadata,
missing_keys,
unexpected_keys,
weight_shape=(self.in_features, self.out_features),
bias_shape=(self.out_features,),
)
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = torch.nn.functional.linear(input, weight, bias)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class Conv1d(torch.nn.Conv1d, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = self._conv_forward(input, weight, bias)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class Conv2d(torch.nn.Conv2d, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = self._conv_forward(input, weight, bias)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class Conv3d(torch.nn.Conv3d, CastWeightBiasOp):
def reset_parameters(self):
return None
def _conv_forward(self, input, weight, bias, autopad=None, *args, **kwargs):
if autopad == "causal_zero":
weight = weight[:, :, -input.shape[2]:, :, :]
if NVIDIA_MEMORY_CONV_BUG_WORKAROUND and weight.dtype in (torch.float16, torch.bfloat16):
out = torch.cudnn_convolution(input, weight, self.padding, self.stride, self.dilation, self.groups, benchmark=False, deterministic=False, allow_tf32=True)
if bias is not None:
out += bias.reshape((1, -1) + (1,) * (out.ndim - 2))
return out
else:
return super()._conv_forward(input, weight, bias, *args, **kwargs)
def forward_comfy_cast_weights(self, input, autopad=None):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = self._conv_forward(input, weight, bias, autopad=autopad)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0 or "autopad" in kwargs:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class GroupNorm(torch.nn.GroupNorm, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = torch.nn.functional.group_norm(input, self.num_groups, weight, bias, self.eps)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class LayerNorm(torch.nn.LayerNorm, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
if self.weight is not None:
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
else:
weight = None
bias = None
offload_stream = None
x = torch.nn.functional.layer_norm(input, self.normalized_shape, weight, bias, self.eps)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class RMSNorm(torch.nn.RMSNorm, CastWeightBiasOp):
def reset_parameters(self):
self.bias = None
return None
def forward_comfy_cast_weights(self, input):
if self.weight is not None:
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
else:
weight = None
bias = None
offload_stream = None
x = torch.nn.functional.rms_norm(input, self.normalized_shape, weight, self.eps)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class ConvTranspose2d(torch.nn.ConvTranspose2d, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input, output_size=None):
num_spatial_dims = 2
output_padding = self._output_padding(
input, output_size, self.stride, self.padding, self.kernel_size,
num_spatial_dims, self.dilation)
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = torch.nn.functional.conv_transpose2d(
input, weight, bias, self.stride, self.padding,
output_padding, self.groups, self.dilation)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class ConvTranspose1d(torch.nn.ConvTranspose1d, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input, output_size=None):
num_spatial_dims = 1
output_padding = self._output_padding(
input, output_size, self.stride, self.padding, self.kernel_size,
num_spatial_dims, self.dilation)
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = torch.nn.functional.conv_transpose1d(
input, weight, bias, self.stride, self.padding,
output_padding, self.groups, self.dilation)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
class Embedding(torch.nn.Embedding, CastWeightBiasOp):
def __init__(self, num_embeddings, embedding_dim, padding_idx=None, max_norm=None,
norm_type=2.0, scale_grad_by_freq=False, sparse=False, _weight=None,
_freeze=False, device=None, dtype=None):
# don't trust subclasses that BYO state dict loader to call us.
if (not comfy.model_management.WINDOWS
or not comfy.memory_management.aimdo_enabled
or type(self)._load_from_state_dict is not disable_weight_init.Embedding._load_from_state_dict):
super().__init__(num_embeddings, embedding_dim, padding_idx, max_norm,
norm_type, scale_grad_by_freq, sparse, _weight,
_freeze, device, dtype)
return
torch.nn.Module.__init__(self)
self.num_embeddings = num_embeddings
self.embedding_dim = embedding_dim
self.padding_idx = padding_idx
self.max_norm = max_norm
self.norm_type = norm_type
self.scale_grad_by_freq = scale_grad_by_freq
self.sparse = sparse
# Keep shape/dtype visible for module introspection without reserving storage.
embedding_dtype = dtype if dtype is not None else torch.get_default_dtype()
self.weight = torch.nn.Parameter(
torch.empty((num_embeddings, embedding_dim), device="meta", dtype=embedding_dtype),
requires_grad=False,
)
self.bias = None
self.weight_comfy_model_dtype = dtype
def _load_from_state_dict(self, state_dict, prefix, local_metadata,
strict, missing_keys, unexpected_keys, error_msgs):
if (not comfy.model_management.WINDOWS
or not comfy.memory_management.aimdo_enabled
or type(self)._load_from_state_dict is not disable_weight_init.Embedding._load_from_state_dict):
return super()._load_from_state_dict(state_dict, prefix, local_metadata, strict,
missing_keys, unexpected_keys, error_msgs)
disable_weight_init._lazy_load_from_state_dict(
self,
state_dict,
prefix,
local_metadata,
missing_keys,
unexpected_keys,
weight_shape=(self.num_embeddings, self.embedding_dim),
)
def reset_parameters(self):
self.bias = None
return None
def forward_comfy_cast_weights(self, input, out_dtype=None):
output_dtype = out_dtype
if self.weight.dtype == torch.float16 or self.weight.dtype == torch.bfloat16:
out_dtype = None
weight, bias, offload_stream = cast_bias_weight(self, device=input.device, dtype=out_dtype, offloadable=True)
x = torch.nn.functional.embedding(input, weight, self.padding_idx, self.max_norm, self.norm_type, self.scale_grad_by_freq, self.sparse).to(dtype=output_dtype)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
if "out_dtype" in kwargs:
kwargs.pop("out_dtype")
return super().forward(*args, **kwargs)
@classmethod
def conv_nd(s, dims, *args, **kwargs):
if dims == 2:
return s.Conv2d(*args, **kwargs)
elif dims == 3:
return s.Conv3d(*args, **kwargs)
else:
raise ValueError(f"unsupported dimensions: {dims}")
class manual_cast(disable_weight_init):
class Linear(disable_weight_init.Linear):
comfy_cast_weights = True
class Conv1d(disable_weight_init.Conv1d):
comfy_cast_weights = True
class Conv2d(disable_weight_init.Conv2d):
comfy_cast_weights = True
class Conv3d(disable_weight_init.Conv3d):
comfy_cast_weights = True
class GroupNorm(disable_weight_init.GroupNorm):
comfy_cast_weights = True
class LayerNorm(disable_weight_init.LayerNorm):
comfy_cast_weights = True
class ConvTranspose2d(disable_weight_init.ConvTranspose2d):
comfy_cast_weights = True
class ConvTranspose1d(disable_weight_init.ConvTranspose1d):
comfy_cast_weights = True
class RMSNorm(disable_weight_init.RMSNorm):
comfy_cast_weights = True
class Embedding(disable_weight_init.Embedding):
comfy_cast_weights = True
def fp8_linear(self, input):
"""
Legacy FP8 linear function for backward compatibility.
Uses QuantizedTensor subclass for dispatch.
"""
dtype = self.weight.dtype
if dtype not in [torch.float8_e4m3fn]:
return None
input_dtype = input.dtype
input_shape = input.shape
tensor_3d = input.ndim == 3
if tensor_3d:
input = input.reshape(-1, input_shape[2])
if input.ndim != 2:
return None
lora_compute_dtype=comfy.model_management.lora_compute_dtype(input.device)
w, bias, offload_stream = cast_bias_weight(self, input, dtype=dtype, bias_dtype=input_dtype, offloadable=True, compute_dtype=lora_compute_dtype, want_requant=True)
scale_weight = torch.ones((), device=input.device, dtype=torch.float32)
scale_input = torch.ones((), device=input.device, dtype=torch.float32)
input = torch.clamp(input, min=-448, max=448, out=input)
input_fp8 = input.to(dtype).contiguous()
layout_params_input = TensorCoreFP8Layout.Params(scale=scale_input, orig_dtype=input_dtype, orig_shape=tuple(input_fp8.shape))
quantized_input = QuantizedTensor(input_fp8, "TensorCoreFP8Layout", layout_params_input)
# Wrap weight in QuantizedTensor - this enables unified dispatch
# Call F.linear - __torch_dispatch__ routes to fp8_linear handler in quant_ops.py!
layout_params_weight = TensorCoreFP8Layout.Params(scale=scale_weight, orig_dtype=input_dtype, orig_shape=tuple(w.shape))
quantized_weight = QuantizedTensor(w, "TensorCoreFP8Layout", layout_params_weight)
o = torch.nn.functional.linear(quantized_input, quantized_weight, bias)
uncast_bias_weight(self, w, bias, offload_stream)
if tensor_3d:
o = o.reshape((input_shape[0], input_shape[1], w.shape[0]))
return o
class fp8_ops(manual_cast):
class Linear(manual_cast.Linear):
def reset_parameters(self):
self.scale_weight = None
self.scale_input = None
return None
def forward_comfy_cast_weights(self, input):
if len(self.weight_function) == 0 and len(self.bias_function) == 0:
try:
out = fp8_linear(self, input)
if out is not None:
return out
except Exception as e:
logging.info("Exception during fp8 op: {}".format(e))
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = torch.nn.functional.linear(input, weight, bias)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
CUBLAS_IS_AVAILABLE = False
try:
from cublas_ops import CublasLinear, cublas_half_matmul
CUBLAS_IS_AVAILABLE = True
except ImportError:
pass
if CUBLAS_IS_AVAILABLE:
class cublas_ops(manual_cast):
class Linear(CublasLinear, manual_cast.Linear):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True)
x = cublas_half_matmul(input, weight, bias, self._epilogue_str, self.has_bias)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, *args, **kwargs):
run_every_op()
if self.comfy_cast_weights or len(self.weight_function) > 0 or len(self.bias_function) > 0:
return self.forward_comfy_cast_weights(*args, **kwargs)
else:
return super().forward(*args, **kwargs)
# ==============================================================================
# Mixed Precision Operations
# ==============================================================================
from .quant_ops import (
QuantizedTensor,
QUANT_ALGOS,
TensorCoreFP8Layout,
get_layout_class,
)
class QuantLinearFunc(torch.autograd.Function):
"""Custom autograd function for quantized linear: quantized forward, optionally FP8 backward.
When training_fp8_bwd is enabled:
- Forward: quantize input per layout (FP8/NVFP4), use quantized matmul
- Backward: all matmuls use FP8 tensor cores via torch.mm dispatch
- Cached input is FP8 (half the memory of bf16)
When training_fp8_bwd is disabled:
- Forward: quantize input per layout, use quantized matmul
- Backward: dequantize weight to compute_dtype, use standard matmul
"""
@staticmethod
def forward(ctx, input_float, weight, bias, layout_type, input_scale, compute_dtype):
input_shape = input_float.shape
inp = input_float.detach().flatten(0, -2) # zero-cost view to 2D
# Quantize input for forward (same layout as weight)
if layout_type is not None:
q_input = QuantizedTensor.from_float(inp, layout_type, scale=input_scale)
else:
q_input = inp
w = weight.detach() if weight.requires_grad else weight
b = bias.detach() if bias is not None and bias.requires_grad else bias
output = torch.nn.functional.linear(q_input, w, b)
# Unflatten output to match original input shape
if len(input_shape) > 2:
output = output.unflatten(0, input_shape[:-1])
# Save for backward
ctx.input_shape = input_shape
ctx.has_bias = bias is not None
ctx.compute_dtype = compute_dtype
ctx.weight_requires_grad = weight.requires_grad
ctx.fp8_bwd = comfy.model_management.training_fp8_bwd
if ctx.fp8_bwd:
# Cache FP8 quantized input — half the memory of bf16
if isinstance(q_input, QuantizedTensor) and layout_type.startswith('TensorCoreFP8'):
ctx.q_input = q_input # already FP8, reuse
else:
# NVFP4 or other layout — quantize input to FP8 for backward
ctx.q_input = QuantizedTensor.from_float(inp, "TensorCoreFP8E4M3Layout")
ctx.save_for_backward(weight)
else:
ctx.q_input = None
ctx.save_for_backward(input_float, weight)
return output
@staticmethod
@torch.autograd.function.once_differentiable
def backward(ctx, grad_output):
compute_dtype = ctx.compute_dtype
grad_2d = grad_output.flatten(0, -2).to(compute_dtype)
# Value casting — only difference between fp8 and non-fp8 paths
if ctx.fp8_bwd:
weight, = ctx.saved_tensors
# Wrap as FP8 QuantizedTensors → torch.mm dispatches to _scaled_mm
grad_mm = QuantizedTensor.from_float(grad_2d, "TensorCoreFP8E5M2Layout")
if isinstance(weight, QuantizedTensor) and weight._layout_cls.startswith("TensorCoreFP8"):
weight_mm = weight
elif isinstance(weight, QuantizedTensor):
weight_mm = QuantizedTensor.from_float(weight.dequantize().to(compute_dtype), "TensorCoreFP8E4M3Layout")
else:
weight_mm = QuantizedTensor.from_float(weight.to(compute_dtype), "TensorCoreFP8E4M3Layout")
input_mm = ctx.q_input
else:
input_float, weight = ctx.saved_tensors
# Standard tensors → torch.mm does regular matmul
grad_mm = grad_2d
if isinstance(weight, QuantizedTensor):
weight_mm = weight.dequantize().to(compute_dtype)
else:
weight_mm = weight.to(compute_dtype)
input_mm = input_float.flatten(0, -2).to(compute_dtype) if ctx.weight_requires_grad else None
# Computation — same for both paths, dispatch handles the rest
grad_input = torch.mm(grad_mm, weight_mm)
if len(ctx.input_shape) > 2:
grad_input = grad_input.unflatten(0, ctx.input_shape[:-1])
grad_weight = None
if ctx.weight_requires_grad:
grad_weight = torch.mm(grad_mm.t(), input_mm)
grad_bias = None
if ctx.has_bias:
grad_bias = grad_2d.sum(dim=0)
return grad_input, grad_weight, grad_bias, None, None, None
def mixed_precision_ops(quant_config={}, compute_dtype=torch.bfloat16, full_precision_mm=False, disabled=[]):
class MixedPrecisionOps(manual_cast):
_quant_config = quant_config
_compute_dtype = compute_dtype
_full_precision_mm = full_precision_mm
_disabled = disabled
class Linear(torch.nn.Module, CastWeightBiasOp):
def __init__(
self,
in_features: int,
out_features: int,
bias: bool = True,
device=None,
dtype=None,
) -> None:
super().__init__()
self.factory_kwargs = {"device": device, "dtype": MixedPrecisionOps._compute_dtype}
# self.factory_kwargs = {"device": device, "dtype": dtype}
self.in_features = in_features
self.out_features = out_features
if bias:
self.bias = torch.nn.Parameter(torch.empty(out_features, **self.factory_kwargs))
else:
self.register_parameter("bias", None)
self.tensor_class = None
self._full_precision_mm = MixedPrecisionOps._full_precision_mm
self._full_precision_mm_config = False
def reset_parameters(self):
return None
def _load_scale_param(self, state_dict, prefix, param_name, device, manually_loaded_keys, dtype=None):
key = f"{prefix}{param_name}"
value = state_dict.pop(key, None)
if value is not None:
value = value.to(device=device)
if dtype is not None:
value = value.view(dtype=dtype)
manually_loaded_keys.append(key)
return value
def _load_from_state_dict(self, state_dict, prefix, local_metadata,
strict, missing_keys, unexpected_keys, error_msgs):
device = self.factory_kwargs["device"]
layer_name = prefix.rstrip('.')
weight_key = f"{prefix}weight"
weight = state_dict.pop(weight_key, None)
if weight is None:
logging.warning(f"Missing weight for layer {layer_name}")
self.weight = None
return
manually_loaded_keys = [weight_key]
layer_conf = state_dict.pop(f"{prefix}comfy_quant", None)
if layer_conf is not None:
layer_conf = json.loads(layer_conf.numpy().tobytes())
if layer_conf is None:
self.weight = torch.nn.Parameter(weight.to(device=device, dtype=MixedPrecisionOps._compute_dtype), requires_grad=False)
else:
self.quant_format = layer_conf.get("format", None)
self._full_precision_mm_config = layer_conf.get("full_precision_matrix_mult", False)
if not self._full_precision_mm:
self._full_precision_mm = self._full_precision_mm_config
if self.quant_format in MixedPrecisionOps._disabled:
self._full_precision_mm = True
if self.quant_format is None:
raise ValueError(f"Unknown quantization format for layer {layer_name}")
qconfig = QUANT_ALGOS[self.quant_format]
self.layout_type = qconfig["comfy_tensor_layout"]
layout_cls = get_layout_class(self.layout_type)
# Load format-specific parameters
if self.quant_format in ["float8_e4m3fn", "float8_e5m2"]:
# FP8: single tensor scale
scale = self._load_scale_param(state_dict, prefix, "weight_scale", device, manually_loaded_keys)
params = layout_cls.Params(
scale=scale,
orig_dtype=MixedPrecisionOps._compute_dtype,
orig_shape=(self.out_features, self.in_features),
)
elif self.quant_format == "mxfp8":
# MXFP8: E8M0 block scales stored as uint8 in safetensors
block_scale = self._load_scale_param(state_dict, prefix, "weight_scale", device, manually_loaded_keys,
dtype=torch.uint8)
if block_scale is None:
raise ValueError(f"Missing MXFP8 block scales for layer {layer_name}")
block_scale = block_scale.view(torch.float8_e8m0fnu)
params = layout_cls.Params(
scale=block_scale,
orig_dtype=MixedPrecisionOps._compute_dtype,
orig_shape=(self.out_features, self.in_features),
)
elif self.quant_format == "nvfp4":
# NVFP4: tensor_scale (weight_scale_2) + block_scale (weight_scale)
tensor_scale = self._load_scale_param(state_dict, prefix, "weight_scale_2", device, manually_loaded_keys)
block_scale = self._load_scale_param(state_dict, prefix, "weight_scale", device, manually_loaded_keys,
dtype=torch.float8_e4m3fn)
if tensor_scale is None or block_scale is None:
raise ValueError(f"Missing NVFP4 scales for layer {layer_name}")
params = layout_cls.Params(
scale=tensor_scale,
block_scale=block_scale,
orig_dtype=MixedPrecisionOps._compute_dtype,
orig_shape=(self.out_features, self.in_features),
)
else:
raise ValueError(f"Unsupported quantization format: {self.quant_format}")
self.weight = torch.nn.Parameter(
QuantizedTensor(weight.to(device=device, dtype=qconfig["storage_t"]), self.layout_type, params),
requires_grad=False
)
for param_name in qconfig["parameters"]:
if param_name in {"weight_scale", "weight_scale_2"}:
continue # Already handled above
param_key = f"{prefix}{param_name}"
_v = state_dict.pop(param_key, None)
if _v is None:
continue
self.register_parameter(param_name, torch.nn.Parameter(_v.to(device=device), requires_grad=False))
manually_loaded_keys.append(param_key)
super()._load_from_state_dict(state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs)
for key in manually_loaded_keys:
if key in missing_keys:
missing_keys.remove(key)
def state_dict(self, *args, destination=None, prefix="", **kwargs):
if destination is not None:
sd = destination
else:
sd = {}
if not hasattr(self, 'weight'):
logging.warning("Warning: state dict on uninitialized op {}".format(prefix))
return sd
if self.bias is not None:
sd["{}bias".format(prefix)] = self.bias
if self.weight is None:
return sd
if isinstance(self.weight, QuantizedTensor):
sd_out = self.weight.state_dict("{}weight".format(prefix))
for k in sd_out:
sd[k] = sd_out[k]
quant_conf = {"format": self.quant_format}
if self._full_precision_mm_config:
quant_conf["full_precision_matrix_mult"] = True
sd["{}comfy_quant".format(prefix)] = torch.tensor(list(json.dumps(quant_conf).encode('utf-8')), dtype=torch.uint8)
input_scale = getattr(self, 'input_scale', None)
if input_scale is not None:
sd["{}input_scale".format(prefix)] = input_scale
else:
sd["{}weight".format(prefix)] = self.weight
return sd
def _forward(self, input, weight, bias):
return torch.nn.functional.linear(input, weight, bias)
def forward_comfy_cast_weights(self, input, compute_dtype=None, want_requant=False):
weight, bias, offload_stream = cast_bias_weight(self, input, offloadable=True, compute_dtype=compute_dtype, want_requant=want_requant)
x = self._forward(input, weight, bias)
uncast_bias_weight(self, weight, bias, offload_stream)
return x
def forward(self, input, *args, **kwargs):
run_every_op()
input_shape = input.shape
reshaped_3d = False
#If cast needs to apply lora, it should be done in the compute dtype
compute_dtype = input.dtype
_use_quantized = (
getattr(self, 'layout_type', None) is not None and
not isinstance(input, QuantizedTensor) and not self._full_precision_mm and
not getattr(self, 'comfy_force_cast_weights', False) and
len(self.weight_function) == 0 and len(self.bias_function) == 0
)
# Training path: quantized forward with compute_dtype backward via autograd function
if (input.requires_grad and _use_quantized):
weight, bias, offload_stream = cast_bias_weight(
self,
input,
offloadable=True,
compute_dtype=compute_dtype,
want_requant=True
)
scale = getattr(self, 'input_scale', None)
if scale is not None:
scale = comfy.model_management.cast_to_device(scale, input.device, None)
output = QuantLinearFunc.apply(
input, weight, bias, self.layout_type, scale, compute_dtype
)
uncast_bias_weight(self, weight, bias, offload_stream)
return output
# Inference path (unchanged)
if _use_quantized:
# Reshape 3D tensors to 2D for quantization (needed for NVFP4 and others)
input_reshaped = input.reshape(-1, input_shape[2]) if input.ndim == 3 else input
# Fall back to non-quantized for non-2D tensors
if input_reshaped.ndim == 2:
reshaped_3d = input.ndim == 3
# dtype is now implicit in the layout class
scale = getattr(self, 'input_scale', None)
if scale is not None:
scale = comfy.model_management.cast_to_device(scale, input.device, None)
input = QuantizedTensor.from_float(input_reshaped, self.layout_type, scale=scale)
output = self.forward_comfy_cast_weights(input, compute_dtype, want_requant=isinstance(input, QuantizedTensor))
# Reshape output back to 3D if input was 3D
if reshaped_3d:
output = output.reshape((input_shape[0], input_shape[1], self.weight.shape[0]))
return output
def convert_weight(self, weight, inplace=False, **kwargs):
if isinstance(weight, QuantizedTensor):
return weight.dequantize()
else:
return weight
def set_weight(self, weight, inplace_update=False, seed=None, return_weight=False, **kwargs):
if getattr(self, 'layout_type', None) is not None:
# dtype is now implicit in the layout class
weight = QuantizedTensor.from_float(weight, self.layout_type, scale="recalculate", stochastic_rounding=seed, inplace_ops=True).to(self.weight.dtype)
else:
weight = weight.to(self.weight.dtype)
if return_weight:
return weight
assert inplace_update is False # TODO: eventually remove the inplace_update stuff
self.weight = torch.nn.Parameter(weight, requires_grad=False)
def _apply(self, fn, recurse=True): # This is to get torch.compile + moving weights to another device working
if recurse:
for module in self.children():
module._apply(fn)
for key, param in self._parameters.items():
if param is None:
continue
p = fn(param)
if (not torch.is_inference_mode_enabled()) and p.is_inference():
p = p.clone()
self.register_parameter(key, torch.nn.Parameter(p, requires_grad=False))
for key, buf in self._buffers.items():
if buf is not None:
self._buffers[key] = fn(buf)
return self
return MixedPrecisionOps
def pick_operations(weight_dtype, compute_dtype, load_device=None, disable_fast_fp8=False, fp8_optimizations=False, model_config=None):
fp8_compute = comfy.model_management.supports_fp8_compute(load_device) # TODO: if we support more ops this needs to be more granular
nvfp4_compute = comfy.model_management.supports_nvfp4_compute(load_device)
mxfp8_compute = comfy.model_management.supports_mxfp8_compute(load_device)
if model_config and hasattr(model_config, 'quant_config') and model_config.quant_config:
logging.info("Using mixed precision operations")
disabled = set()
if not nvfp4_compute:
disabled.add("nvfp4")
if not mxfp8_compute:
disabled.add("mxfp8")
if not fp8_compute:
disabled.add("float8_e4m3fn")
disabled.add("float8_e5m2")
return mixed_precision_ops(model_config.quant_config, compute_dtype, disabled=disabled)
if (
fp8_compute and
(fp8_optimizations or PerformanceFeature.Fp8MatrixMultiplication in args.fast) and
not disable_fast_fp8
):
return fp8_ops
if (
PerformanceFeature.CublasOps in args.fast and
CUBLAS_IS_AVAILABLE and
weight_dtype == torch.float16 and
(compute_dtype == torch.float16 or compute_dtype is None)
):
logging.info("Using cublas ops")
return cublas_ops
if compute_dtype is None or weight_dtype == compute_dtype:
return disable_weight_init
return manual_cast