Improve RAM<->VRAM memory copy performance in LoRA patching and elsewhere (#6490)

* allow model patcher to optimize away the unpatching step when feasible

* remove lazy_offloading functionality

* allow model patcher to optimize away the unpatching step when feasible

* remove lazy_offloading functionality

* do not save original weights if there is a CPU copy of state dict

* Update invokeai/backend/model_manager/load/load_base.py

Co-authored-by: Ryan Dick <ryanjdick3@gmail.com>

* documentation fixes requested during penultimate review

* add non-blocking=True parameters to several torch.nn.Module.to() calls, for slight performance increases

* fix ruff errors

* prevent crash on non-cuda-enabled systems

---------

Co-authored-by: Lincoln Stein <lstein@gmail.com>
Co-authored-by: Kent Keirsey <31807370+hipsterusername@users.noreply.github.com>
Co-authored-by: Ryan Dick <ryanjdick3@gmail.com>
This commit is contained in:
Lincoln Stein
2024-06-13 13:10:03 -04:00
committed by GitHub
parent 568a4844f7
commit a3cb5da130
7 changed files with 84 additions and 38 deletions

View File

@ -67,7 +67,7 @@ class ModelPatcher:
unet: UNet2DConditionModel,
loras: Iterator[Tuple[LoRAModelRaw, float]],
model_state_dict: Optional[Dict[str, torch.Tensor]] = None,
) -> None:
) -> Generator[None, None, None]:
with cls.apply_lora(
unet,
loras=loras,
@ -83,7 +83,7 @@ class ModelPatcher:
text_encoder: CLIPTextModel,
loras: Iterator[Tuple[LoRAModelRaw, float]],
model_state_dict: Optional[Dict[str, torch.Tensor]] = None,
) -> None:
) -> Generator[None, None, None]:
with cls.apply_lora(text_encoder, loras=loras, prefix="lora_te_", model_state_dict=model_state_dict):
yield
@ -95,7 +95,7 @@ class ModelPatcher:
loras: Iterator[Tuple[LoRAModelRaw, float]],
prefix: str,
model_state_dict: Optional[Dict[str, torch.Tensor]] = None,
) -> Generator[Any, None, None]:
) -> Generator[None, None, None]:
"""
Apply one or more LoRAs to a model.
@ -139,12 +139,12 @@ class ModelPatcher:
# We intentionally move to the target device first, then cast. Experimentally, this was found to
# be significantly faster for 16-bit CPU tensors being moved to a CUDA device than doing the
# same thing in a single call to '.to(...)'.
layer.to(device=device)
layer.to(dtype=torch.float32)
layer.to(device=device, non_blocking=True)
layer.to(dtype=torch.float32, non_blocking=True)
# TODO(ryand): Using torch.autocast(...) over explicit casting may offer a speed benefit on CUDA
# devices here. Experimentally, it was found to be very slow on CPU. More investigation needed.
layer_weight = layer.get_weight(module.weight) * (lora_weight * layer_scale)
layer.to(device=torch.device("cpu"))
layer.to(device=torch.device("cpu"), non_blocking=True)
assert isinstance(layer_weight, torch.Tensor) # mypy thinks layer_weight is a float|Any ??!
if module.weight.shape != layer_weight.shape:
@ -153,7 +153,7 @@ class ModelPatcher:
layer_weight = layer_weight.reshape(module.weight.shape)
assert isinstance(layer_weight, torch.Tensor) # mypy thinks layer_weight is a float|Any ??!
module.weight += layer_weight.to(dtype=dtype)
module.weight += layer_weight.to(dtype=dtype, non_blocking=True)
yield # wait for context manager exit
@ -161,7 +161,7 @@ class ModelPatcher:
assert hasattr(model, "get_submodule") # mypy not picking up fact that torch.nn.Module has get_submodule()
with torch.no_grad():
for module_key, weight in original_weights.items():
model.get_submodule(module_key).weight.copy_(weight)
model.get_submodule(module_key).weight.copy_(weight, non_blocking=True)
@classmethod
@contextmanager