vllm/examples/offline_inference/spec_decode.py

138 lines
5.0 KiB
Python

# SPDX-License-Identifier: Apache-2.0
from transformers import AutoTokenizer
from vllm import LLM, SamplingParams
from vllm.benchmarks.datasets import add_dataset_parser, get_samples
from vllm.v1.metrics.reader import Counter, Vector
try:
from vllm.utils import FlexibleArgumentParser
except ImportError:
from argparse import ArgumentParser as FlexibleArgumentParser
def parse_args():
parser = FlexibleArgumentParser()
add_dataset_parser(parser)
parser.add_argument(
"--dataset",
type=str,
default="./examples/data/gsm8k.jsonl",
help="downloaded from the eagle repo "
"https://github.com/SafeAILab/EAGLE/blob/main/eagle/data/",
)
parser.add_argument(
"--method", type=str, default="eagle", choices=["ngram", "eagle", "eagle3"]
)
parser.add_argument("--max-num-seqs", type=int, default=8)
parser.add_argument("--num-spec-tokens", type=int, default=2)
parser.add_argument("--prompt-lookup-max", type=int, default=5)
parser.add_argument("--prompt-lookup-min", type=int, default=2)
parser.add_argument("--tp", type=int, default=1)
parser.add_argument("--draft-tp", type=int, default=1)
parser.add_argument("--enforce-eager", action="store_true")
parser.add_argument("--enable-chunked-prefill", action="store_true")
parser.add_argument("--max-num-batched-tokens", type=int, default=2048)
parser.add_argument("--temp", type=float, default=0)
parser.add_argument("--top-p", type=float, default=1.0)
parser.add_argument("--top-k", type=int, default=-1)
parser.add_argument("--print-output", action="store_true")
parser.add_argument("--output-len", type=int, default=256)
return parser.parse_args()
def main():
args = parse_args()
args.endpoint_type = "openai-chat"
model_dir = "meta-llama/Llama-3.1-8B-Instruct"
tokenizer = AutoTokenizer.from_pretrained(model_dir)
max_model_len = 2048
prompts = get_samples(args, tokenizer)
# add_special_tokens is False to avoid adding bos twice when using chat templates
prompt_ids = [
tokenizer.encode(prompt.prompt, add_special_tokens=False) for prompt in prompts
]
if args.method == "eagle" or args.method == "eagle3":
if args.method == "eagle":
eagle_dir = "yuhuili/EAGLE-LLaMA3.1-Instruct-8B"
elif args.method == "eagle3":
eagle_dir = "yuhuili/EAGLE3-LLaMA3.1-Instruct-8B"
speculative_config = {
"method": args.method,
"model": eagle_dir,
"num_speculative_tokens": args.num_spec_tokens,
"draft_tensor_parallel_size": args.draft_tp,
"max_model_len": max_model_len,
}
elif args.method == "ngram":
speculative_config = {
"method": "ngram",
"num_speculative_tokens": args.num_spec_tokens,
"prompt_lookup_max": args.prompt_lookup_max,
"prompt_lookup_min": args.prompt_lookup_min,
"max_model_len": max_model_len,
}
else:
raise ValueError(f"unknown method: {args.method}")
llm = LLM(
model=model_dir,
trust_remote_code=True,
tensor_parallel_size=args.tp,
enable_chunked_prefill=args.enable_chunked_prefill,
max_num_batched_tokens=args.max_num_batched_tokens,
enforce_eager=args.enforce_eager,
max_model_len=max_model_len,
max_num_seqs=args.max_num_seqs,
gpu_memory_utilization=0.8,
speculative_config=speculative_config,
disable_log_stats=False,
)
sampling_params = SamplingParams(temperature=args.temp, max_tokens=args.output_len)
outputs = llm.generate(prompt_token_ids=prompt_ids, sampling_params=sampling_params)
# print the generated text
if args.print_output:
for output in outputs:
print("-" * 50)
print(f"prompt: {output.prompt}")
print(f"generated text: {output.outputs[0].text}")
print("-" * 50)
try:
metrics = llm.get_metrics()
except AssertionError:
print("Metrics are not supported in the V0 engine.")
return
num_drafts = num_accepted = 0
acceptance_counts = [0] * args.num_spec_tokens
for metric in metrics:
if metric.name == "vllm:spec_decode_num_drafts":
assert isinstance(metric, Counter)
num_drafts += metric.value
elif metric.name == "vllm:spec_decode_num_accepted_tokens":
assert isinstance(metric, Counter)
num_accepted += metric.value
elif metric.name == "vllm:spec_decode_num_accepted_tokens_per_pos":
assert isinstance(metric, Vector)
for pos in range(len(metric.values)):
acceptance_counts[pos] += metric.values[pos]
print("-" * 50)
print(f"mean acceptance length: {1 + (num_accepted / num_drafts):.2f}")
print("-" * 50)
# print acceptance at each token position
for i in range(len(acceptance_counts)):
print(f"acceptance at token {i}:{acceptance_counts[i] / num_drafts:.2f}")
if __name__ == "__main__":
main()