fix: handle 2GB protobuf limit, add validation, fix input feeds

- Use no_post_process=True for ONNX export to avoid protobuf serialize error
- Add --validate and --validate-only flags for inference verification
- Fix position_ids in validation feed (required by Qwen3 ONNX export)
- Use optimum-cli for quantization to handle external data format
- Fix optimum dependency to optimum[onnxruntime]

Tested: export + validation passes on CPU, KV cache present (56 tensors).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Shreyas Karnik 2026-03-13 12:30:26 -07:00
parent 2df95ac9ba
commit e1ce37c989
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@ -10,7 +10,7 @@
# "sentencepiece>=0.1.99",
# "protobuf>=3.20.0",
# "numpy",
# "optimum>=1.17.0",
# "optimum[onnxruntime]",
# "onnx>=1.15.0",
# "onnxruntime>=1.17.0",
# ]
@ -68,7 +68,7 @@ def merge_adapters(base_model: str, sft_model: str, grpo_model: str) -> tuple:
"""Load base model, merge SFT + GRPO adapters, return (model, tokenizer)."""
print(f"\nStep 1: Loading base model {base_model}...")
model = AutoModelForCausalLM.from_pretrained(
base_model, torch_dtype=torch.float32, trust_remote_code=True,
base_model, dtype=torch.float32, trust_remote_code=True,
)
print(f"Step 2: Merging SFT adapter {sft_model}...")
@ -94,98 +94,193 @@ def export_onnx(model, tokenizer, output_dir: str):
tokenizer.save_pretrained(merged_dir)
print(f"\nStep 5: Exporting to ONNX at {output_dir}...")
# no_post_process=True avoids the 2GB protobuf serialization limit
# that occurs during tied-weight deduplication on large FP32 models.
# The exported model still works correctly — the tied weights just
# aren't deduplicated in the graph, which is fine since we quantize next.
main_export(
model_name_or_path=merged_dir,
output=output_dir,
task="text-generation-with-past",
device="cpu",
fp16=False,
no_post_process=True,
)
# Clean up temp merged dir
shutil.rmtree(merged_dir, ignore_errors=True)
def _find_onnx_model(onnx_dir: str) -> Path:
"""Find the main ONNX model file in the output directory."""
model_path = Path(onnx_dir) / "model.onnx"
if model_path.exists():
return model_path
candidates = list(Path(onnx_dir).glob("*.onnx"))
if not candidates:
raise FileNotFoundError(f"No .onnx files found in {onnx_dir}")
return candidates[0]
def quantize_onnx(onnx_dir: str, quantize_type: str):
"""Quantize the exported ONNX model."""
"""Quantize the exported ONNX model using optimum-cli for memory safety."""
if quantize_type == "none":
print("\nSkipping quantization (FP32).")
return
model_path = Path(onnx_dir) / "model.onnx"
if not model_path.exists():
# Optimum may produce decoder_model.onnx for text-generation-with-past
candidates = list(Path(onnx_dir).glob("*.onnx"))
if not candidates:
print(" WARNING: No .onnx files found to quantize.")
return
model_path = candidates[0]
model_path = _find_onnx_model(onnx_dir)
print(f"\nStep 6: Quantizing {model_path.name} ({quantize_type})...")
q_dir = Path(onnx_dir) / f"quantized_{quantize_type}"
q_dir.mkdir(exist_ok=True)
if quantize_type == "q4":
try:
from onnxruntime.quantization import matmul_nbits_quantizer
quant = matmul_nbits_quantizer.MatMulNBitsQuantizer(
model=str(model_path),
block_size=32,
is_symmetric=True,
bits=4,
)
quant.process()
q_path = model_path.with_name(
model_path.stem + "_q4" + model_path.suffix,
)
quant.model.save(str(q_path))
size_mb = q_path.stat().st_size / (1024 * 1024)
print(f" Q4: {size_mb:.1f} MB -> {q_path.name}")
except ImportError:
print(" WARNING: onnxruntime quantization not available, trying alternative...")
_quantize_dynamic(model_path, quantize_type)
# Use optimum-cli which handles external data format and memory properly.
# Direct MatMulNBitsQuantizer can OOM on large FP32 models.
cmd = [
sys.executable, "-m", "optimum.commands.optimum_cli",
"onnxruntime", "quantize",
"--onnx_model", onnx_dir,
"--o", str(q_dir),
"--avx2",
]
print(f" Running: optimum-cli onnxruntime quantize ...")
result = subprocess.run(cmd, capture_output=True, text=True)
if result.returncode != 0:
print(f" optimum-cli failed, falling back to MatMulNBitsQuantizer...")
_quantize_q4_direct(model_path, q_dir)
elif quantize_type == "q8":
_quantize_dynamic(model_path, quantize_type)
cmd = [
sys.executable, "-m", "optimum.commands.optimum_cli",
"onnxruntime", "quantize",
"--onnx_model", onnx_dir,
"--o", str(q_dir),
"--avx2",
]
result = subprocess.run(cmd, capture_output=True, text=True)
if result.returncode != 0:
print(f" optimum-cli quantize failed: {result.stderr[:300]}")
elif quantize_type == "fp16":
_convert_fp16(model_path)
_convert_fp16_external(model_path, q_dir)
# Report sizes
for f in sorted(q_dir.glob("*.onnx*")):
size_mb = f.stat().st_size / (1024 * 1024)
if size_mb > 1:
print(f" {f.name}: {size_mb:.1f} MB")
# Move quantized files back into main dir, replacing originals
for f in q_dir.iterdir():
dest = Path(onnx_dir) / f.name
if dest.exists():
dest.unlink()
shutil.move(str(f), str(dest))
q_dir.rmdir()
def _quantize_dynamic(model_path: Path, qtype: str):
"""Dynamic quantization fallback."""
from onnxruntime.quantization import quantize_dynamic, QuantType
weight_type = QuantType.QUInt8 if qtype == "q8" else QuantType.QInt8
q_path = model_path.with_name(
model_path.stem + f"_{qtype}" + model_path.suffix,
def _quantize_q4_direct(model_path: Path, output_dir: Path):
"""Direct Q4 quantization fallback (may need significant RAM)."""
from onnxruntime.quantization import matmul_nbits_quantizer
quant = matmul_nbits_quantizer.MatMulNBitsQuantizer(
model=str(model_path),
block_size=32,
is_symmetric=True,
bits=4,
)
quantize_dynamic(
model_input=str(model_path),
model_output=str(q_path),
weight_type=weight_type,
quant.process()
q_path = output_dir / model_path.name
quant.model.save(str(q_path))
def _convert_fp16_external(model_path: Path, output_dir: Path):
"""Convert ONNX model to FP16 using onnxconverter-common (handles external data)."""
print(" Converting to FP16 (external data format)...")
try:
from onnxconverter_common import float16
import onnx
model = onnx.load(str(model_path), load_external_data=True)
model_fp16 = float16.convert_float_to_float16(model, keep_io_types=True)
fp16_path = output_dir / model_path.name
onnx.save(model_fp16, str(fp16_path))
except ImportError:
print(" onnxconverter-common not available; skipping FP16 conversion.")
def validate_onnx(onnx_dir: str, base_model: str):
"""Run a sample inference through the ONNX model to verify it works."""
import onnxruntime as ort
import numpy as np
model_path = _find_onnx_model(onnx_dir)
print(f"\nValidation: loading {model_path.name}...")
tokenizer = AutoTokenizer.from_pretrained(onnx_dir, trust_remote_code=True)
session = ort.InferenceSession(
str(model_path),
providers=["CPUExecutionProvider"],
)
size_mb = q_path.stat().st_size / (1024 * 1024)
print(f" {qtype.upper()}: {size_mb:.1f} MB -> {q_path.name}")
def _convert_fp16(model_path: Path):
"""Convert ONNX model to FP16."""
import onnx
from onnx import numpy_helper
print(" Converting to FP16...")
model = onnx.load(str(model_path))
for initializer in model.graph.initializer:
if initializer.data_type == onnx.TensorProto.FLOAT:
np_data = numpy_helper.to_array(initializer)
initializer.CopyFrom(
numpy_helper.from_array(np_data.astype("float16"), initializer.name),
)
fp16_path = model_path.with_name(
model_path.stem + "_fp16" + model_path.suffix,
# Tokenize a test prompt
test_query = "/no_think Expand this search query: distributed consensus"
chat_prompt = tokenizer.apply_chat_template(
[{"role": "user", "content": test_query}],
add_generation_prompt=True,
tokenize=False,
)
onnx.save(model, str(fp16_path))
size_mb = fp16_path.stat().st_size / (1024 * 1024)
print(f" FP16: {size_mb:.1f} MB -> {fp16_path.name}")
inputs = tokenizer(chat_prompt, return_tensors="np")
input_ids = inputs["input_ids"].astype(np.int64)
attention_mask = inputs["attention_mask"].astype(np.int64)
# Build feed dict with all required inputs
seq_len = input_ids.shape[1]
feed = {"input_ids": input_ids, "attention_mask": attention_mask}
# Add position_ids if needed
all_inputs = {inp.name: inp for inp in session.get_inputs()}
if "position_ids" in all_inputs:
feed["position_ids"] = np.arange(seq_len, dtype=np.int64).reshape(1, -1)
# Initialize past_key_values to zeros if the model expects them
for name, inp in sorted(all_inputs.items()):
if name.startswith("past_key_values"):
shape = []
for dim in inp.shape:
shape.append(dim if isinstance(dim, int) else 0)
# batch dim = 1
if shape and shape[0] == 0:
shape[0] = 1
feed[name] = np.zeros(shape, dtype=np.float32)
# Run inference
output_names = [o.name for o in session.get_outputs()]
results = session.run(output_names, feed)
# Check logits shape
logits = results[0]
print(f" Input tokens: {input_ids.shape[1]}")
print(f" Output logits shape: {logits.shape}")
print(f" Logits range: [{logits.min():.2f}, {logits.max():.2f}]")
# Greedy decode next token
next_token_id = int(np.argmax(logits[0, -1, :]))
next_token = tokenizer.decode([next_token_id])
print(f" Next token: {repr(next_token)} (id={next_token_id})")
# Check KV cache outputs exist
kv_outputs = [n for n in output_names if n.startswith("present")]
if kv_outputs:
print(f" KV cache outputs: {len(kv_outputs)} tensors (generation-ready)")
else:
print(" WARNING: No KV cache outputs — model may not support efficient generation")
# Sanity checks
assert logits.shape[0] == 1, "Batch size mismatch"
assert logits.shape[1] == input_ids.shape[1], "Sequence length mismatch"
assert logits.max() > logits.min(), "Logits are constant (broken model)"
assert not np.isnan(logits).any(), "Logits contain NaN"
assert not np.isinf(logits).any(), "Logits contain Inf"
print(" Validation PASSED")
def write_transformers_js_config(onnx_dir: str):
@ -278,8 +373,21 @@ def main():
parser.add_argument(
"--no-upload", action="store_true", help="Don't upload to HF Hub",
)
parser.add_argument(
"--validate", action="store_true",
help="Run inference validation on exported model",
)
parser.add_argument(
"--validate-only", metavar="DIR",
help="Skip export, only validate an existing ONNX dir",
)
args = parser.parse_args()
# Validate-only mode: skip export, just run validation
if args.validate_only:
validate_onnx(args.validate_only, "")
return
# Resolve config
if args.size:
preset = PRESETS[args.size]
@ -321,6 +429,10 @@ def main():
# Write Transformers.js config
write_transformers_js_config(onnx_dir)
# Validate
if args.validate:
validate_onnx(onnx_dir, base_model)
# Upload
if not args.no_upload:
upload_to_hub(onnx_dir, output_repo, base_model, sft_model, grpo_model)