[Spec Decode] Clean up spec decode example (#20240)

Signed-off-by: Woosuk Kwon <woosuk.kwon@berkeley.edu>
This commit is contained in:
Woosuk Kwon
2025-06-30 08:28:13 -07:00
committed by GitHub
parent 2062c0723d
commit 2965c99c86
2 changed files with 21 additions and 163 deletions

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@ -1,144 +0,0 @@
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import argparse
import json
import os
from transformers import AutoTokenizer
from vllm import LLM, SamplingParams
from vllm.v1.metrics.reader import Counter, Vector
def load_prompts(dataset_path, num_prompts):
if os.path.exists(dataset_path):
prompts = []
try:
with open(dataset_path) as f:
for line in f:
data = json.loads(line)
prompts.append(data["turns"][0])
except Exception as e:
print(f"Error reading dataset: {e}")
return []
else:
prompts = ["The future of AI is", "The president of the United States is"]
return prompts[:num_prompts]
def parse_args():
parser = argparse.ArgumentParser()
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=["eagle", "eagle3"]
)
parser.add_argument("--max_num_seqs", type=int, default=8)
parser.add_argument("--num_prompts", type=int, default=80)
parser.add_argument("--num_spec_tokens", 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)
return parser.parse_args()
def main():
args = parse_args()
model_dir = "meta-llama/Llama-3.1-8B-Instruct"
if args.method == "eagle":
eagle_dir = "yuhuili/EAGLE-LLaMA3.1-Instruct-8B"
elif args.method == "eagle3":
eagle_dir = "yuhuili/EAGLE3-LLaMA3.1-Instruct-8B"
else:
raise ValueError(f"unknown method: {args.method}")
max_model_len = 2048
tokenizer = AutoTokenizer.from_pretrained(model_dir)
prompts = load_prompts(args.dataset, args.num_prompts)
prompt_ids = [
tokenizer.apply_chat_template(
[{"role": "user", "content": prompt}], add_generation_prompt=True
)
for prompt in prompts
]
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={
"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,
},
disable_log_stats=False,
)
sampling_params = SamplingParams(temperature=args.temp, max_tokens=256)
outputs = llm.generate(prompt_token_ids=prompt_ids, sampling_params=sampling_params)
# print the generated text
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__":
print(
"[WARNING] Use examples/offline_inference/spec_decode.py"
" instead of this script."
)
main()

View File

@ -16,24 +16,17 @@ def parse_args():
parser = FlexibleArgumentParser()
add_dataset_parser(parser)
parser.add_argument(
"--dataset",
"--method",
type=str,
default="./examples/data/gsm8k.jsonl",
help="downloaded from the eagle repo "
"https://github.com/SafeAILab/EAGLE/blob/main/eagle/data/",
default="eagle",
choices=["ngram", "eagle", "eagle3", "mtp"],
)
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)
@ -41,7 +34,6 @@ def parse_args():
parser.add_argument("--output-len", type=int, default=256)
parser.add_argument("--model-dir", type=str, default=None)
parser.add_argument("--eagle-dir", type=str, default=None)
parser.add_argument("--max-model-len", type=int, default=2048)
return parser.parse_args()
@ -71,8 +63,6 @@ def main():
"method": args.method,
"model": eagle_dir,
"num_speculative_tokens": args.num_spec_tokens,
"draft_tensor_parallel_size": args.draft_tp,
"max_model_len": args.max_model_len,
}
elif args.method == "ngram":
speculative_config = {
@ -80,7 +70,6 @@ def main():
"num_speculative_tokens": args.num_spec_tokens,
"prompt_lookup_max": args.prompt_lookup_max,
"prompt_lookup_min": args.prompt_lookup_min,
"max_model_len": args.max_model_len,
}
else:
raise ValueError(f"unknown method: {args.method}")
@ -92,7 +81,6 @@ def main():
enable_chunked_prefill=args.enable_chunked_prefill,
max_num_batched_tokens=args.max_num_batched_tokens,
enforce_eager=args.enforce_eager,
max_model_len=args.max_model_len,
max_num_seqs=args.max_num_seqs,
gpu_memory_utilization=0.8,
speculative_config=speculative_config,
@ -116,27 +104,41 @@ def main():
print("Metrics are not supported in the V0 engine.")
return
num_drafts = num_accepted = 0
total_num_output_tokens = sum(
len(output.outputs[0].token_ids) for output in outputs
)
num_drafts = 0
num_draft_tokens = 0
num_accepted_tokens = 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_draft_tokens":
assert isinstance(metric, Counter)
num_draft_tokens += metric.value
elif metric.name == "vllm:spec_decode_num_accepted_tokens":
assert isinstance(metric, Counter)
num_accepted += metric.value
num_accepted_tokens += 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(f"total_num_output_tokens: {total_num_output_tokens}")
print(f"num_drafts: {num_drafts}")
print(f"num_draft_tokens: {num_draft_tokens}")
print(f"num_accepted_tokens: {num_accepted_tokens}")
acceptance_length = 1 + (num_accepted_tokens / num_drafts) if num_drafts > 0 else 1
print(f"mean acceptance length: {acceptance_length:.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}")
acceptance_rate = acceptance_counts[i] / num_drafts if num_drafts > 0 else 0
print(f"acceptance at token {i}: {acceptance_rate:.2f}")
if __name__ == "__main__":