Files
nano-vllm/bench_offload.py
2026-01-07 02:32:30 +08:00

92 lines
3.6 KiB
Python

import os
import time
from random import randint, seed
from nanovllm import LLM, SamplingParams
def bench_decode(llm, num_seqs, input_len, output_len):
"""Benchmark decode performance (original test)"""
seed(0)
prompt_token_ids = [[randint(0, 10000) for _ in range(input_len)] for _ in range(num_seqs)]
sampling_params = SamplingParams(temperature=0.6, ignore_eos=True, max_tokens=output_len)
t = time.time()
llm.generate(prompt_token_ids, sampling_params, use_tqdm=False)
t = time.time() - t
total_output_tokens = num_seqs * output_len
throughput = total_output_tokens / t
print(f"[Decode] Input: {num_seqs}x{input_len}tok, Output: {total_output_tokens}tok, Time: {t:.2f}s, Throughput: {throughput:.2f}tok/s")
def bench_prefill(llm, num_seqs, input_len):
"""Benchmark prefill performance"""
seed(0)
# Fixed length input, minimal output to focus on prefill
prompt_token_ids = [[randint(0, 10000) for _ in range(input_len)] for _ in range(num_seqs)]
sampling_params = SamplingParams(temperature=0.6, ignore_eos=True, max_tokens=1)
t = time.time()
llm.generate(prompt_token_ids, sampling_params, use_tqdm=False)
t = time.time() - t
total_input_tokens = num_seqs * input_len
throughput = total_input_tokens / t
print(f"[Prefill] Input: {total_input_tokens}tok ({num_seqs}x{input_len}), Time: {t:.2f}s, Throughput: {throughput:.2f}tok/s")
def main():
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("--no-sparse", action="store_true", help="Disable sparse attention (baseline)")
parser.add_argument("--topk", type=int, default=8, help="Top-K blocks for Quest")
parser.add_argument("--input-len", type=int, default=None, help="Input length in tokens (default: max_len - 1 for prefill, max_len - output_len for decode)")
parser.add_argument("--output-len", type=int, default=128, help="Output length in tokens")
args = parser.parse_args()
path = os.path.expanduser("~/models/Qwen3-4B-Instruct-2507/")
# Note: Qwen3-4B-Instruct-2507 max_position_embeddings = 262144
max_len = 32 * 1024 # 128K tokens
# Setup policy configuration
if not args.no_sparse:
prefill_policy = "full" # Full attention for prefill
decode_policy = "quest" # Quest Top-K for decode
print(f"\n[Quest Sparse Attention] prefill={prefill_policy}, decode={decode_policy}, topk={args.topk}")
else:
prefill_policy = "full" # Full attention for both phases
decode_policy = "full"
print("\n[Full Attention] No sparse policy (baseline)")
llm = LLM(
path,
enforce_eager=False,
max_model_len=max_len,
max_num_batched_tokens=max_len,
enable_cpu_offload=True,
num_gpu_blocks=6, # Small GPU buffer for offload testing
prefill_policy=prefill_policy,
decode_policy=decode_policy,
sparse_topk_blocks=args.topk,
sparse_threshold_blocks=4,
)
# Warmup
llm.generate(["Benchmark: "], SamplingParams())
# Default input lengths based on max_len
prefill_input_len = args.input_len if args.input_len else max_len - 1
decode_input_len = args.input_len if args.input_len else max_len - args.output_len
print("=" * 60)
print("Prefill Benchmark (CPU Offload)")
print("=" * 60)
bench_prefill(llm, num_seqs=1, input_len=prefill_input_len)
# print("=" * 60)
# print("Decode Benchmark (CPU Offload)")
# print("=" * 60)
# bench_decode(llm, num_seqs=1, input_len=decode_input_len, output_len=args.output_len)
if __name__ == "__main__":
main()