ComfyUI/comfy/ops.py
loxotron b9f5145f4d Add fast_sampler.py with optimized sampling and VAE decoding, enhance PreviewImage
This commit introduces `fast_sampler.py`, a new module designed to enhance the performance of sampling and VAE decoding in ComfyUI. It replaces or augments functionality previously handled in `model_management.py`, providing better VRAM management, FP16 support, and tiled decoding for low-memory scenarios. Additionally, it improves the `PreviewImage` node in `nodes.py` for faster and more efficient preview generation. These changes improve efficiency, stability, and usability, particularly for GPU-based workflows.

**Key Changes:**
- Implemented `fast_ksampler` for optimized sampling with improved memory management, FP16 support via `torch.amp.autocast`, and `channels_last` memory format for better GPU performance.
- Added `fast_vae_decode` for efficient VAE decoding, incorporating FP16 support, `channels_last`, and selective VRAM clearing to prevent out-of-memory errors.
- Introduced `fast_vae_tiled_decode` for tiled VAE decoding, enabling processing of large latents on GPUs with limited VRAM by using configurable tile sizes and overlaps.
- Added profiling and debugging utilities (`profile_section`, `profile_cuda_sync`) to track execution times and VRAM usage when `--profile` or `--debug` flags are enabled.
- Improved VRAM management with `clear_vram`, ensuring sufficient free memory before loading models or VAE, with configurable thresholds and minimum free memory requirements.
- Implemented `is_fp16_safe` to check GPU compatibility for FP16 operations, disabling them on unsupported hardware (e.g., GTX 1660/Turing).
- Optimized tensor transfers with `optimized_transfer` and `optimized_conditioning` for synchronous device placement and dtype casting.
- Enhanced model preloading with `preload_model`, which unloads VAE before loading U-Net to conserve VRAM and checks for already-loaded VAE to avoid redundant transfers.
- Integrated `cudnn.benchmark` for for tests, disabled by default.
- VRAM should now be managed efficiently.
- Updated `PreviewImage` node in `nodes.py` to support adaptive resizing of preview images to a maximum dimension of ~512 pixels while preserving aspect ratio, using `Image.LANCZOS` for quality. Increased `compress_level` from 1 to 4 for faster PNG compression, optimizing preview generation.

**Impact:**
- Significantly reduces VRAM usage during sampling and VAE decoding, making ComfyUI more stable on GPUs with limited memory.
- Improves performance for large-scale image generation through tiled decoding and FP16 optimizations.
- Enhances debugging capabilities with detailed profiling and logging, aiding development and optimization.

**Dependencies:**
- Relies on `nodes.py` for integration with `KSampler`, `VAEDecode`, `VAEDecodeTiled`, and `PreviewImage` nodes.
- Assumes compatibility with existing `ModelPatcher` functionality for model patching (e.g., in `LoraLoader`).

**Notes:**
- Users should enable `--profile` or `--debug` flags to access detailed performance logs.
- FP16 support requires compatible GPU hardware (compute capability ≥ 8 or > 7).
- Tiled decoding parameters (`tile_size`, `overlap`, etc.) may need tuning for specific workflows.
- Preview images are now smaller and faster to generate, but users can adjust `max_size` in `PreviewImage` if higher resolution previews are needed.

This is a foundational change to improve ComfyUI's performance and scalability, particularly for resource-constrained environments.

Thanks to Grok @ xAI for help.
2025-05-15 06:54:33 +03:00

439 lines
17 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
from comfy.cli_args import args, PerformanceFeature
import comfy.float
import comfy.rmsnorm
import contextlib
from comfy.utils import cast_to
cast_to = cast_to # Maintain compatibility with code expecting comfy.ops.cast_to
def cast_to_input(weight, input, non_blocking=False, copy=True):
return cast_to(weight, input.dtype, input.device, non_blocking=non_blocking, copy=copy)
def cast_bias_weight(s, input=None, dtype=None, device=None, bias_dtype=None):
if input is not None:
if dtype is None:
dtype = input.dtype
if bias_dtype is None:
bias_dtype = dtype
if device is None:
device = input.device
offload_stream = comfy.model_management.get_offload_stream(device)
if offload_stream is not None:
wf_context = offload_stream
else:
wf_context = contextlib.nullcontext()
bias = None
non_blocking = comfy.model_management.device_supports_non_blocking(device)
if s.bias is not None:
has_function = len(s.bias_function) > 0
bias = cast_to(s.bias, bias_dtype, device, non_blocking=non_blocking, copy=has_function, stream=offload_stream)
if has_function:
with wf_context:
for f in s.bias_function:
bias = f(bias)
has_function = len(s.weight_function) > 0
weight = cast_to(s.weight, dtype, device, non_blocking=non_blocking, copy=has_function, stream=offload_stream)
if has_function:
with wf_context:
for f in s.weight_function:
weight = f(weight)
comfy.model_management.sync_stream(device, offload_stream)
return weight, bias
class CastWeightBiasOp:
comfy_cast_weights = False
weight_function = []
bias_function = []
class disable_weight_init:
class Linear(torch.nn.Linear, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias = cast_bias_weight(self, input)
return torch.nn.functional.linear(input, weight, bias)
def forward(self, *args, **kwargs):
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 = cast_bias_weight(self, input)
return self._conv_forward(input, weight, bias)
def forward(self, *args, **kwargs):
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 = cast_bias_weight(self, input)
return self._conv_forward(input, weight, bias)
def forward(self, *args, **kwargs):
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 forward_comfy_cast_weights(self, input):
weight, bias = cast_bias_weight(self, input)
return self._conv_forward(input, weight, bias)
def forward(self, *args, **kwargs):
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 GroupNorm(torch.nn.GroupNorm, CastWeightBiasOp):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
weight, bias = cast_bias_weight(self, input)
return torch.nn.functional.group_norm(input, self.num_groups, weight, bias, self.eps)
def forward(self, *args, **kwargs):
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 = cast_bias_weight(self, input)
else:
weight = None
bias = None
return torch.nn.functional.layer_norm(input, self.normalized_shape, weight, bias, self.eps)
def forward(self, *args, **kwargs):
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(comfy.rmsnorm.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 = cast_bias_weight(self, input)
else:
weight = None
return comfy.rmsnorm.rms_norm(input, weight, self.eps) # TODO: switch to commented out line when old torch is deprecated
# return torch.nn.functional.rms_norm(input, self.normalized_shape, weight, self.eps)
def forward(self, *args, **kwargs):
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 = cast_bias_weight(self, input)
return torch.nn.functional.conv_transpose2d(
input, weight, bias, self.stride, self.padding,
output_padding, self.groups, self.dilation)
def forward(self, *args, **kwargs):
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 = cast_bias_weight(self, input)
return torch.nn.functional.conv_transpose1d(
input, weight, bias, self.stride, self.padding,
output_padding, self.groups, self.dilation)
def forward(self, *args, **kwargs):
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 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 = cast_bias_weight(self, device=input.device, dtype=out_dtype)
return 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)
def forward(self, *args, **kwargs):
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):
dtype = self.weight.dtype
if dtype not in [torch.float8_e4m3fn]:
return None
tensor_2d = False
if len(input.shape) == 2:
tensor_2d = True
input = input.unsqueeze(1)
input_shape = input.shape
input_dtype = input.dtype
if len(input.shape) == 3:
w, bias = cast_bias_weight(self, input, dtype=dtype, bias_dtype=input_dtype)
w = w.t()
scale_weight = self.scale_weight
scale_input = self.scale_input
if scale_weight is None:
scale_weight = torch.ones((), device=input.device, dtype=torch.float32)
else:
scale_weight = scale_weight.to(input.device)
if scale_input is None:
scale_input = torch.ones((), device=input.device, dtype=torch.float32)
input = torch.clamp(input, min=-448, max=448, out=input)
input = input.reshape(-1, input_shape[2]).to(dtype)
else:
scale_input = scale_input.to(input.device)
input = (input * (1.0 / scale_input).to(input_dtype)).reshape(-1, input_shape[2]).to(dtype)
if bias is not None:
o = torch._scaled_mm(input, w, out_dtype=input_dtype, bias=bias, scale_a=scale_input, scale_b=scale_weight)
else:
o = torch._scaled_mm(input, w, out_dtype=input_dtype, scale_a=scale_input, scale_b=scale_weight)
if isinstance(o, tuple):
o = o[0]
if tensor_2d:
return o.reshape(input_shape[0], -1)
return o.reshape((-1, input_shape[1], self.weight.shape[0]))
return None
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):
out = fp8_linear(self, input)
if out is not None:
return out
weight, bias = cast_bias_weight(self, input)
return torch.nn.functional.linear(input, weight, bias)
def scaled_fp8_ops(fp8_matrix_mult=False, scale_input=False, override_dtype=None):
logging.info("Using scaled fp8: fp8 matrix mult: {}, scale input: {}".format(fp8_matrix_mult, scale_input))
class scaled_fp8_op(manual_cast):
class Linear(manual_cast.Linear):
def __init__(self, *args, **kwargs):
if override_dtype is not None:
kwargs['dtype'] = override_dtype
super().__init__(*args, **kwargs)
def reset_parameters(self):
if not hasattr(self, 'scale_weight'):
self.scale_weight = torch.nn.parameter.Parameter(data=torch.ones((), device=self.weight.device, dtype=torch.float32), requires_grad=False)
if not scale_input:
self.scale_input = None
if not hasattr(self, 'scale_input'):
self.scale_input = torch.nn.parameter.Parameter(data=torch.ones((), device=self.weight.device, dtype=torch.float32), requires_grad=False)
return None
def forward_comfy_cast_weights(self, input):
if fp8_matrix_mult:
out = fp8_linear(self, input)
if out is not None:
return out
weight, bias = cast_bias_weight(self, input)
if weight.numel() < input.numel(): #TODO: optimize
return torch.nn.functional.linear(input, weight * self.scale_weight.to(device=weight.device, dtype=weight.dtype), bias)
else:
return torch.nn.functional.linear(input * self.scale_weight.to(device=weight.device, dtype=weight.dtype), weight, bias)
def convert_weight(self, weight, inplace=False, **kwargs):
if inplace:
weight *= self.scale_weight.to(device=weight.device, dtype=weight.dtype)
return weight
else:
return weight * self.scale_weight.to(device=weight.device, dtype=weight.dtype)
def set_weight(self, weight, inplace_update=False, seed=None, **kwargs):
weight = comfy.float.stochastic_rounding(weight / self.scale_weight.to(device=weight.device, dtype=weight.dtype), self.weight.dtype, seed=seed)
if inplace_update:
self.weight.data.copy_(weight)
else:
self.weight = torch.nn.Parameter(weight, requires_grad=False)
return scaled_fp8_op
CUBLAS_IS_AVAILABLE = False
try:
from cublas_ops import CublasLinear
CUBLAS_IS_AVAILABLE = True
except ImportError:
pass
if CUBLAS_IS_AVAILABLE:
class cublas_ops(disable_weight_init):
class Linear(CublasLinear, disable_weight_init.Linear):
def reset_parameters(self):
return None
def forward_comfy_cast_weights(self, input):
return super().forward(input)
def forward(self, *args, **kwargs):
return super().forward(*args, **kwargs)
def pick_operations(weight_dtype, compute_dtype, load_device=None, disable_fast_fp8=False, fp8_optimizations=False, scaled_fp8=None):
fp8_compute = comfy.model_management.supports_fp8_compute(load_device)
if scaled_fp8 is not None:
return scaled_fp8_ops(fp8_matrix_mult=fp8_compute and fp8_optimizations, scale_input=fp8_optimizations, override_dtype=scaled_fp8)
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