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CalamitousFelicitousness 9b37a1535c fix(lora): exact lora application on sdnq-quantized layers
Baking a lora into a quantized weight requantizes it, and on low-bit
formats round-to-nearest erases sub-step deltas (uint4 retains roughly
2/group_size of the signal). Plain lora deltas now ride the sdnq svd
side-channel: factors append to svd_up/svd_down with the down factor
hadamard-rotated, applied by the dequantizer at full precision in every
forward mode. Apply and remove are exact and take no weight backup.

- non-factorable families (dora, lokr, loha, oft, cp mid, dense bias)
  fall back to requantize with a per-pass summary warning
- native fuse now honors the quantized-model guard; fuse requantized in
  place on every network swap and accumulated drift
- layers that fell back on a mixed set restore from backup before
  re-entering the factor path; untargeted quantized layers are no
  longer flagged
- test/test-sdnq-lora-factors.py pins the erasure law, factor-path
  exactness, memory accounting and set transitions
2026-08-25 00:25:22 +01:00

133 lines
4.8 KiB
Python

from modules import shared
force_hashes_diffusers = [ # forced always
# '816d0eed49fd', # flash-sdxl
# 'c2ec22757b46', # flash-sd15
# '22c8339e7666', # spo-sdxl-10ep
# 'aaebf6360f7d', # sd15-lcm
# '3d18b05e4f56', # sdxl-lcm
# 'b71dcb732467', # sdxl-tcd
# '813ea5fb1c67', # sdxl-turbo
# '5a48ac366664', # hyper-sd15-1step
# 'ee0ff23dcc42', # hyper-sd15-2step
# 'e476eb1da5df', # hyper-sd15-4step
# 'ecb844c3f3b0', # hyper-sd15-8step
# '1ab289133ebb', # hyper-sd15-8step-cfg
# '4f494295edb1', # hyper-sdxl-8step
# 'ca14a8c621f8', # hyper-sdxl-8step-cfg
# '1c88f7295856', # hyper-sdxl-4step
# 'fdd5dcd1d88a', # hyper-sdxl-2step
# '8cca3706050b', # hyper-sdxl-1step
]
allow_native = [
'sd',
'sdxl',
'sd3',
'f1',
'f2',
'chroma',
'zimage',
'anima',
'ernieimage',
'krea2',
]
force_classes_diffusers = [ # forced always
'FluxKontextPipeline', 'FluxKontextInpaintPipeline',
]
fuse_ignore = [
'hunyuanvideo',
]
def get_method(shorthash=''):
"""Return ``(method, reason)`` for the active LoRA loading strategy.
``method`` is one of ``'native'``, ``'diffusers'``, ``'nunchaku'``.
``reason`` is a short identifier indicating which condition triggered the
chosen method, useful for distinguishing user-opt-in from automatic
fallback in logs. Reasons:
- ``'nunchaku-transformer'`` / ``'nunchaku-unet'``: a Nunchaku-quantized
component is loaded.
- ``'opt-in'``: ``shared.opts.lora_force_diffusers`` is on (settings).
- ``'class-forced'``: pipeline class is in ``force_classes_diffusers``.
- ``'arch-unsupported'``: ``sd_model_type`` is not in ``allow_native``.
- ``'hash-forced'``: file hash is in ``force_hashes_diffusers``.
- ``'default'``: native path is the active and unforced choice.
"""
nunchaku_dit = hasattr(shared.sd_model, 'transformer') and 'Nunchaku' in shared.sd_model.transformer.__class__.__name__
nunchaku_unet = hasattr(shared.sd_model, 'unet') and 'Nunchaku' in shared.sd_model.unet.__class__.__name__
if nunchaku_dit:
return 'nunchaku', 'nunchaku-transformer'
if nunchaku_unet:
return 'nunchaku', 'nunchaku-unet'
if shared.opts.lora_force_diffusers:
return 'diffusers', 'opt-in'
if shared.sd_model.__class__.__name__ in force_classes_diffusers:
return 'diffusers', 'class-forced'
if shared.sd_model_type not in allow_native:
return 'diffusers', 'arch-unsupported'
if len(shorthash) > 4 and any(x.startswith(shorthash) for x in force_hashes_diffusers):
return 'diffusers', 'hash-forced'
return 'native', 'default'
# Roles a LoRA is fused into; a quantized component in any of them makes fusing unsafe.
fuse_roots = ('transformer', 'unet', 'text_encoder', 'llm_adapter')
def fuse_components(sd_model):
"""Component names a network fuses into, matched by role prefix so numbered and reference siblings are covered."""
names = getattr(sd_model, 'components', None)
if not isinstance(names, dict):
names = vars(sd_model)
return [name for name in names if name.startswith(fuse_roots)]
def is_quantized(module):
"""Return True when ``module`` carries a quantization config.
``config.quantization_config`` is read first: SDNQ sets both it and the plain
attribute when it quantizes in place, but a checkpoint that ships pre-quantized
only reaches the plain attribute through the diffusers ConfigMixin name proxy,
which is deprecated for removal.
"""
if module is None:
return False
config = getattr(module, 'config', None)
if config is not None and getattr(config, 'quantization_config', None) is not None:
return True
return getattr(module, 'quantization_config', None) is not None
def disable_fuse():
"""Return True when fusing a network into model weights is unsafe.
Fusing keeps no pristine copy of the weight, so each apply and restore
round-trips it through its storage format. On quantized weights that is a
dequantize-add-requantize cycle per network swap whose error compounds.
"""
sd_model = getattr(shared.sd_model, 'pipe', shared.sd_model)
if is_quantized(sd_model):
return True
if any(is_quantized(getattr(sd_model, name, None)) for name in fuse_components(sd_model)):
return True
if hasattr(sd_model, '_lora_partial'):
return True
return shared.sd_model_type in fuse_ignore
def fuse_native():
"""Return True when the native apply path may fuse into model weights.
The single source of truth for the native fuse decision: it must agree across
the backup, activate and deactivate passes, since backup mode restores from a
stored tensor while fuse mode restores by subtracting the delta.
"""
return shared.opts.lora_fuse_native and not disable_fuse()