[inference] update examples and engine (#5073)

* update examples and engine

* fix choices

* update example

examples/inference/build_smoothquant_weight.py

@@ -0,0 +1,68 @@
+import argparse
+import os
+
+import torch
+from datasets import load_dataset
+from transformers import LlamaTokenizer
+
+from colossalai.inference.quant.smoothquant.models.llama import SmoothLlamaForCausalLM
+
+
+def build_model_and_tokenizer(model_name):
+    tokenizer = LlamaTokenizer.from_pretrained(model_name, model_max_length=512)
+    kwargs = {"torch_dtype": torch.float16, "device_map": "sequential"}
+    model = SmoothLlamaForCausalLM.from_pretrained(model_name, **kwargs)
+    model = model.to(torch.float32)
+    return model, tokenizer
+
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--model-name", type=str, help="model name")
+    parser.add_argument(
+        "--output-path",
+        type=str,
+        help="where to save the checkpoint",
+    )
+    parser.add_argument(
+        "--dataset-path",
+        type=str,
+        help="location of the calibration dataset",
+    )
+    parser.add_argument("--num-samples", type=int, default=10)
+    parser.add_argument("--seq-len", type=int, default=512)
+    args = parser.parse_args()
+    return args
+
+
+@torch.no_grad()
+def main():
+    args = parse_args()
+    model_path = args.model_name
+    dataset_path = args.dataset_path
+    output_path = args.output_path
+    num_samples = args.num_samples
+    seq_len = args.seq_len
+
+    model, tokenizer = build_model_and_tokenizer(model_path)
+    if not os.path.exists(dataset_path):
+        raise FileNotFoundError(f"Cannot find the dataset at {args.dataset_path}")
+    dataset = load_dataset("json", data_files=dataset_path, split="train")
+
+    model.quantized(tokenizer, dataset, num_samples=num_samples, seq_len=seq_len)
+    model = model.cuda()
+
+    model.save_quantized(output_path, model_basename="llama-7b")
+
+    model = SmoothLlamaForCausalLM.from_quantized(output_path, model_basename="llama-7b")
+    model = model.cuda()
+
+    generate_kwargs = dict(max_new_tokens=16, do_sample=False, use_cache=True)
+    input_tokens = tokenizer(["today is "], return_tensors="pt").to("cuda")
+    out = model.generate(**input_tokens, **generate_kwargs)
+    text = tokenizer.batch_decode(out)
+    print("out is:", text)
+
+
+if __name__ == "__main__":
+    main()