Files
Gahow Wang 445e491123 Add vLLM v0.18.1 source tree with KV transfer abort fix
third_party/vllm/ now tracked in git for direct patch management.
Based on vLLM v0.18.1 release with one patch applied:

  vllm/v1/core/sched/scheduler.py:
    Replace fatal assert with graceful skip when KV transfer callback
    arrives for an already-aborted request during PD disaggregated serving.

Future vLLM modifications should be made directly in third_party/vllm/
and committed normally. The patches/ directory is kept as documentation
of what changed from upstream.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-05-22 00:30:38 +08:00

73 lines
2.1 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
This file demonstrates the usage of text generation with an LLM model,
comparing the performance with and without speculative decoding.
Note that this example is out of date and not supported in vLLM v1.
"""
import gc
import time
from vllm import LLM, SamplingParams
def time_generation(
llm: LLM, prompts: list[str], sampling_params: SamplingParams, title: str
):
# Generate texts from the prompts. The output is a list of RequestOutput
# objects that contain the prompt, generated text, and other information.
# Warmup first
llm.generate(prompts, sampling_params)
llm.generate(prompts, sampling_params)
start = time.time()
outputs = llm.generate(prompts, sampling_params)
end = time.time()
print("-" * 50)
print(title)
print("time: ", (end - start) / sum(len(o.outputs[0].token_ids) for o in outputs))
# Print the outputs.
for output in outputs:
generated_text = output.outputs[0].text
print(f"text: {generated_text!r}")
print("-" * 50)
def main():
template = (
"Below is an instruction that describes a task. Write a response "
"that appropriately completes the request.\n\n### Instruction:\n{}"
"\n\n### Response:\n"
)
# Sample prompts.
prompts = [
"Write about the president of the United States.",
]
prompts = [template.format(prompt) for prompt in prompts]
# Create a sampling params object.
sampling_params = SamplingParams(temperature=0.0, max_tokens=200)
# Create an LLM without spec decoding
llm = LLM(model="meta-llama/Llama-2-13b-chat-hf")
time_generation(llm, prompts, sampling_params, "Without speculation")
del llm
gc.collect()
# Create an LLM with spec decoding
llm = LLM(
model="meta-llama/Llama-2-13b-chat-hf",
speculative_config={
"model": "ibm-ai-platform/llama-13b-accelerator",
},
)
time_generation(llm, prompts, sampling_params, "With speculation")
if __name__ == "__main__":
main()