copy model from a meta device template

- temporarily disable vram cache
This commit is contained in:
Lincoln Stein 2024-06-24 10:55:15 -04:00
parent 6932f27b43
commit 2219e3643a
4 changed files with 40 additions and 122 deletions

View File

@ -52,11 +52,10 @@ class CacheRecord(Generic[T]):
Elements of the cache:
key: Unique key for each model, same as used in the models database.
model: Model in memory.
model: Read-only copy of the model *without weights* residing in the "meta device"
state_dict: A read-only copy of the model's state dict in RAM. It will be
used as a template for creating a copy in the VRAM.
size: Size of the model
loaded: True if the model's state dict is currently in VRAM
Before a model is executed, the state_dict template is copied into VRAM,
and then injected into the model. When the model is finished, the VRAM
@ -72,25 +71,7 @@ class CacheRecord(Generic[T]):
key: str
size: int
model: T
device: torch.device
state_dict: Optional[Dict[str, torch.Tensor]]
size: int
loaded: bool = False
_locks: int = 0
def lock(self) -> None:
"""Lock this record."""
self._locks += 1
def unlock(self) -> None:
"""Unlock this record."""
self._locks -= 1
assert self._locks >= 0
@property
def locked(self) -> bool:
"""Return true if record is locked."""
return self._locks > 0
@dataclass

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@ -36,6 +36,7 @@ from invokeai.backend.model_manager.load.model_util import calc_model_size_by_da
from invokeai.backend.util.devices import TorchDevice
from invokeai.backend.util.logging import InvokeAILogger
from ..optimizations import skip_torch_weight_init
from .model_cache_base import CacheRecord, CacheStats, ModelCacheBase, ModelLockerBase
from .model_locker import ModelLocker
@ -221,8 +222,12 @@ class ModelCache(ModelCacheBase[AnyModel]):
size = calc_model_size_by_data(model)
self.make_room(size)
state_dict = model.state_dict() if isinstance(model, torch.nn.Module) else None
cache_record = CacheRecord(key=key, model=model, device=self.storage_device, state_dict=state_dict, size=size)
if isinstance(model, torch.nn.Module):
state_dict = model.state_dict() # keep a master copy of the state dict
model = model.to(device="meta") # and keep a template in the meta device
else:
state_dict = None
cache_record = CacheRecord(key=key, model=model, state_dict=state_dict, size=size)
self._cached_models[key] = cache_record
self._cache_stack.append(key)
@ -284,48 +289,20 @@ class ModelCache(ModelCacheBase[AnyModel]):
else:
return model_key
def offload_unlocked_models(self, size_required: int) -> None:
"""Move any unused models from VRAM."""
device = self.get_execution_device()
reserved = self._max_vram_cache_size * GIG
vram_in_use = torch.cuda.memory_allocated(device) + size_required
self.logger.debug(f"{(vram_in_use/GIG):.2f}GB VRAM needed for models; max allowed={(reserved/GIG):.2f}GB")
for _, cache_entry in sorted(self._cached_models.items(), key=lambda x: x[1].size):
if vram_in_use <= reserved:
break
if not cache_entry.loaded:
continue
if cache_entry.device is not device:
continue
if not cache_entry.locked:
self.move_model_to_device(cache_entry, self.storage_device)
cache_entry.loaded = False
vram_in_use = torch.cuda.memory_allocated() + size_required
self.logger.debug(
f"Removing {cache_entry.key} from VRAM to free {(cache_entry.size/GIG):.2f}GB; vram free = {(torch.cuda.memory_allocated()/GIG):.2f}GB"
)
TorchDevice.empty_cache()
def move_model_to_device(self, cache_entry: CacheRecord[AnyModel], target_device: torch.device) -> None:
"""Move model into the indicated device.
def model_to_device(self, cache_entry: CacheRecord[AnyModel], target_device: torch.device) -> AnyModel:
"""Move a copy of the model into the indicated device and return it.
:param cache_entry: The CacheRecord for the model
:param target_device: The torch.device to move the model into
May raise a torch.cuda.OutOfMemoryError
"""
self.logger.debug(f"Called to move {cache_entry.key} to {target_device}")
source_device = cache_entry.device
self.logger.info(f"Called to move {cache_entry.key} to {target_device}")
# Note: We compare device types only so that 'cuda' == 'cuda:0'.
# This would need to be revised to support multi-GPU.
if torch.device(source_device).type == torch.device(target_device).type:
return
# Some models don't have a `to` method, in which case they run in RAM/CPU.
if not hasattr(cache_entry.model, "to"):
return
# Some models don't have a state dictionary, in which case the
# stored model will still reside in CPU
if cache_entry.state_dict is None:
return cache_entry.model
# This roundabout method for moving the model around is done to avoid
# the cost of moving the model from RAM to VRAM and then back from VRAM to RAM.
@ -338,27 +315,25 @@ class ModelCache(ModelCacheBase[AnyModel]):
# in RAM into the model. So this operation is very fast.
start_model_to_time = time.time()
snapshot_before = self._capture_memory_snapshot()
try:
if cache_entry.state_dict is not None:
assert hasattr(cache_entry.model, "load_state_dict")
if target_device == self.storage_device:
cache_entry.model.load_state_dict(cache_entry.state_dict, assign=True)
assert isinstance(cache_entry.model, torch.nn.Module)
template = cache_entry.model
cls = template.__class__
with skip_torch_weight_init():
if hasattr(cls, "from_config"):
working_model = template.__class__.from_config(template.config) # diffusers style
else:
new_dict: Dict[str, torch.Tensor] = {}
for k, v in cache_entry.state_dict.items():
new_dict[k] = v.to(torch.device(target_device), copy=True, non_blocking=True)
cache_entry.model.load_state_dict(new_dict, assign=True)
cache_entry.model.to(target_device, non_blocking=True)
cache_entry.device = target_device
working_model = template.__class__(config=template.config) # transformers style (sigh)
working_model.to(device=target_device, dtype=self._precision)
working_model.load_state_dict(cache_entry.state_dict)
except Exception as e: # blow away cache entry
self._delete_cache_entry(cache_entry)
raise e
snapshot_after = self._capture_memory_snapshot()
end_model_to_time = time.time()
self.logger.debug(
f"Moved model '{cache_entry.key}' from {source_device} to"
self.logger.info(
f"Moved model '{cache_entry.key}' to"
f" {target_device} in {(end_model_to_time-start_model_to_time):.2f}s."
f"Estimated model size: {(cache_entry.size/GIG):.3f} GB."
f"{get_pretty_snapshot_diff(snapshot_before, snapshot_after)}"
@ -380,34 +355,21 @@ class ModelCache(ModelCacheBase[AnyModel]):
abs_tol=10 * MB,
):
self.logger.debug(
f"Moving model '{cache_entry.key}' from {source_device} to"
f"Moving model '{cache_entry.key}' from to"
f" {target_device} caused an unexpected change in VRAM usage. The model's"
" estimated size may be incorrect. Estimated model size:"
f" {(cache_entry.size/GIG):.3f} GB.\n"
f"{get_pretty_snapshot_diff(snapshot_before, snapshot_after)}"
)
return working_model
def print_cuda_stats(self) -> None:
"""Log CUDA diagnostics."""
vram = "%4.2fG" % (torch.cuda.memory_allocated() / GIG)
ram = "%4.2fG" % (self.cache_size() / GIG)
in_ram_models = 0
in_vram_models = 0
locked_in_vram_models = 0
for cache_record in self._cached_models.values():
if hasattr(cache_record.model, "device"):
if cache_record.model.device == self.storage_device:
in_ram_models += 1
else:
in_vram_models += 1
if cache_record.locked:
locked_in_vram_models += 1
self.logger.debug(
f"Current VRAM/RAM usage: {vram}/{ram}; models_in_ram/models_in_vram(locked) ="
f" {in_ram_models}/{in_vram_models}({locked_in_vram_models})"
)
in_ram_models = len(self._cached_models)
self.logger.debug(f"Current VRAM/RAM usage for {in_ram_models} models: {vram}/{ram}")
def make_room(self, size: int) -> None:
"""Make enough room in the cache to accommodate a new model of indicated size."""
@ -433,29 +395,6 @@ class ModelCache(ModelCacheBase[AnyModel]):
refs = sys.getrefcount(cache_entry.model)
# HACK: This is a workaround for a memory-management issue that we haven't tracked down yet. We are directly
# going against the advice in the Python docs by using `gc.get_referrers(...)` in this way:
# https://docs.python.org/3/library/gc.html#gc.get_referrers
# manualy clear local variable references of just finished function calls
# for some reason python don't want to collect it even by gc.collect() immidiately
if refs > 2:
while True:
cleared = False
for referrer in gc.get_referrers(cache_entry.model):
if type(referrer).__name__ == "frame":
# RuntimeError: cannot clear an executing frame
with suppress(RuntimeError):
referrer.clear()
cleared = True
# break
# repeat if referrers changes(due to frame clear), else exit loop
if cleared:
gc.collect()
else:
break
device = cache_entry.model.device if hasattr(cache_entry.model, "device") else None
self.logger.debug(
f"Model: {model_key}, locks: {cache_entry._locks}, device: {device}, loaded: {cache_entry.loaded},"

View File

@ -37,25 +37,22 @@ class ModelLocker(ModelLockerBase):
def lock(self) -> AnyModel:
"""Move the model into the execution device (GPU) and lock it."""
self._cache_entry.lock()
try:
device = self._cache.get_execution_device()
self._cache.offload_unlocked_models(self._cache_entry.size)
self._cache.move_model_to_device(self._cache_entry, device)
self._cache_entry.loaded = True
self._cache.logger.debug(f"Locking {self._cache_entry.key} in {device}")
model_on_device = self._cache.model_to_device(self._cache_entry, device)
self._cache.logger.debug(f"Moved {self._cache_entry.key} to {device}")
self._cache.print_cuda_stats()
except torch.cuda.OutOfMemoryError:
self._cache.logger.warning("Insufficient GPU memory to load model. Aborting")
self._cache_entry.unlock()
raise
except Exception:
self._cache_entry.unlock()
raise
return self.model
return model_on_device
# It is no longer necessary to move the model out of VRAM
# because it will be removed when it goes out of scope
# in the caller's context
def unlock(self) -> None:
"""Call upon exit from context."""
self._cache_entry.unlock()
self._cache.print_cuda_stats()

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@ -129,9 +129,7 @@ class ModelPatcher:
dtype = module.weight.dtype
if module_key not in original_weights:
if model_state_dict is not None: # we were provided with the CPU copy of the state dict
original_weights[module_key] = model_state_dict[module_key + ".weight"]
else:
if model_state_dict is None: # no CPU copy of the state dict was provided
original_weights[module_key] = module.weight.detach().to(device="cpu", copy=True)
layer_scale = layer.alpha / layer.rank if (layer.alpha and layer.rank) else 1.0
@ -158,6 +156,9 @@ class ModelPatcher:
yield # wait for context manager exit
finally:
# LS check: for now, we are not reusing models in VRAM but re-copying them each time they are needed.
# Therefore it should not be necessary to copy the original model weights back.
# This needs to be fixed before resurrecting the VRAM cache.
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():