send weights to target device instead of CPU memory

This commit is contained in:
AUTOMATIC1111 2023-08-16 12:11:01 +03:00
parent 57e59c14c8
commit eaba3d7349
2 changed files with 31 additions and 10 deletions

View File

@ -155,10 +155,16 @@ class LoadStateDictOnMeta(ReplaceHelper):
```
"""
def __init__(self, state_dict, device):
def __init__(self, state_dict, device, weight_dtype_conversion=None):
super().__init__()
self.state_dict = state_dict
self.device = device
self.weight_dtype_conversion = weight_dtype_conversion or {}
self.default_dtype = self.weight_dtype_conversion.get('')
def get_weight_dtype(self, key):
key_first_term, _ = key.split('.', 1)
return self.weight_dtype_conversion.get(key_first_term, self.default_dtype)
def __enter__(self):
if shared.cmd_opts.disable_model_loading_ram_optimization:
@ -167,24 +173,24 @@ class LoadStateDictOnMeta(ReplaceHelper):
sd = self.state_dict
device = self.device
def load_from_state_dict(original, self, state_dict, prefix, *args, **kwargs):
def load_from_state_dict(original, module, state_dict, prefix, *args, **kwargs):
used_param_keys = []
for name, param in self._parameters.items():
for name, param in module._parameters.items():
if param is None:
continue
key = prefix + name
sd_param = sd.pop(key, None)
if sd_param is not None:
state_dict[key] = sd_param
state_dict[key] = sd_param.to(dtype=self.get_weight_dtype(key))
used_param_keys.append(key)
if param.is_meta:
dtype = sd_param.dtype if sd_param is not None else param.dtype
self._parameters[name] = torch.nn.parameter.Parameter(torch.zeros_like(param, device=device, dtype=dtype), requires_grad=param.requires_grad)
module._parameters[name] = torch.nn.parameter.Parameter(torch.zeros_like(param, device=device, dtype=dtype), requires_grad=param.requires_grad)
for name in self._buffers:
for name in module._buffers:
key = prefix + name
sd_param = sd.pop(key, None)
@ -192,12 +198,12 @@ class LoadStateDictOnMeta(ReplaceHelper):
state_dict[key] = sd_param
used_param_keys.append(key)
original(self, state_dict, prefix, *args, **kwargs)
original(module, state_dict, prefix, *args, **kwargs)
for key in used_param_keys:
state_dict.pop(key, None)
def load_state_dict(original, self, state_dict, strict=True):
def load_state_dict(original, module, state_dict, strict=True):
"""torch makes a lot of copies of the dictionary with weights, so just deleting entries from state_dict does not help
because the same values are stored in multiple copies of the dict. The trick used here is to give torch a dict with
all weights on meta device, i.e. deleted, and then it doesn't matter how many copies torch makes.
@ -212,7 +218,7 @@ class LoadStateDictOnMeta(ReplaceHelper):
if state_dict == sd:
state_dict = {k: v.to(device="meta", dtype=v.dtype) for k, v in state_dict.items()}
original(self, state_dict, strict=strict)
original(module, state_dict, strict=strict)
module_load_state_dict = self.replace(torch.nn.Module, 'load_state_dict', lambda *args, **kwargs: load_state_dict(module_load_state_dict, *args, **kwargs))
module_load_from_state_dict = self.replace(torch.nn.Module, '_load_from_state_dict', lambda *args, **kwargs: load_from_state_dict(module_load_from_state_dict, *args, **kwargs))

View File

@ -518,6 +518,13 @@ def send_model_to_cpu(m):
devices.torch_gc()
def model_target_device():
if shared.cmd_opts.lowvram or shared.cmd_opts.medvram:
return devices.cpu
else:
return devices.device
def send_model_to_device(m):
if shared.cmd_opts.lowvram or shared.cmd_opts.medvram:
lowvram.setup_for_low_vram(m, shared.cmd_opts.medvram)
@ -579,7 +586,15 @@ def load_model(checkpoint_info=None, already_loaded_state_dict=None):
timer.record("create model")
with sd_disable_initialization.LoadStateDictOnMeta(state_dict, devices.cpu):
if shared.cmd_opts.no_half:
weight_dtype_conversion = None
else:
weight_dtype_conversion = {
'first_stage_model': None,
'': torch.float16,
}
with sd_disable_initialization.LoadStateDictOnMeta(state_dict, device=model_target_device(), weight_dtype_conversion=weight_dtype_conversion):
load_model_weights(sd_model, checkpoint_info, state_dict, timer)
timer.record("load weights from state dict")