unsloth/scripts/int8_linear_probe.py
Daniel Han 36df317293 Trim the comments across the diffusion backend
Comment-only pass over the Python this PR touches: drop what the code already
says, collapse multi-line explanations that still read on one line, and keep
the reasoning that is not recoverable from the code. No code, docstring
semantics or behaviour changes; verified with an AST comparison against the
previous revision, and the backend suite is unchanged (same 37 environment
failures as before: the API integration tests that need a live keyed server,
the flash-attn install hooks, and the GPU memory fields).
2026-07-26 20:31:19 +00:00

88 lines
3.5 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
"""Examine which Linear layers the int8 dense-quant filter would select, to find the large M=1
modulation/embedder projections that crash torch._int_mm (M>16). Loads each transformer on the
META device (no weights, no GPU) from its base-repo config, lists nn.Linear fqn/in/out, and marks
those that pass min_features=512. CPU-only, fast."""
from __future__ import annotations
import os
import sys
from pathlib import Path
sys.path.insert(0, str(Path(__file__).resolve().parent.parent / "studio" / "backend"))
# (label, transformer_class, base_repo)
MODELS = [
("flux.1-dev", "FluxTransformer2DModel", "black-forest-labs/FLUX.1-dev"),
("qwen-image", "QwenImageTransformer2DModel", "Qwen/Qwen-Image"),
("z-image", "ZImageTransformer2DModel", "Tongyi-MAI/Z-Image-Turbo"),
("flux.2-klein-4b", "Flux2Transformer2DModel", "black-forest-labs/FLUX.2-klein-4B"),
]
MIN = 512
def main() -> int:
import diffusers
import torch
from accelerate import init_empty_weights
tok = os.environ.get("HF_TOKEN")
for label, cls_name, base in MODELS:
cls = getattr(diffusers, cls_name, None)
if cls is None:
print(f"\n### {label}: {cls_name} NOT in diffusers")
continue
try:
cfg = cls.load_config(base, subfolder = "transformer", token = tok)
with init_empty_weights():
model = cls.from_config(cfg)
except Exception as e: # noqa: BLE001
print(f"\n### {label}: load failed {type(e).__name__}: {e}")
continue
lins = [(n, m) for n, m in model.named_modules() if isinstance(m, torch.nn.Linear)]
selected = [(n, m) for n, m in lins if m.in_features >= MIN and m.out_features >= MIN]
print(f"\n### {label}: {len(lins)} Linear, {len(selected)} pass min_features={MIN}")
# A modulation/embedder Linear sits outside the repeated blocks (no numeric index in its fqn),
# or has an AdaLN out==k*in (k>=3) shape.
sus = []
for n, m in selected:
depth_idx = any(p.isdigit() for p in n.split("."))
ratio = m.out_features / m.in_features if m.in_features else 0
tag = []
if not depth_idx:
tag.append("NO-BLOCK-IDX")
if ratio >= 3:
tag.append(f"out={ratio:.0f}xin")
if any(
t in n.lower()
for t in ("norm", "embed", "time", "guidance", "modulation", "adaln", "cond")
):
tag.append("NAME")
if tag:
sus.append((n, m.in_features, m.out_features, ",".join(tag)))
# Print the distinct fqn shapes (collapse block indices to {i})
import re
seen = {}
for n, i, o, tag in sus:
key = re.sub(r"\.\d+\.", ".{i}.", n)
seen.setdefault((key, i, o, tag), 0)
seen[(key, i, o, tag)] += 1
print(f" SUSPECT (M=1 risk) distinct patterns:")
for (key, i, o, tag), cnt in sorted(seen.items()):
print(f" [{cnt:>3}x] {key:55s} {i:>6}->{o:<6} [{tag}]")
# Also show a few non-suspect selected names for contrast (the real FLOP linears)
good = [
n
for n, m in selected
if (n, m.in_features, m.out_features) not in {(s[0], s[1], s[2]) for s in sus}
][:6]
print(f" kept-for-int8 examples: {good}")
return 0
if __name__ == "__main__":
raise SystemExit(main())