359 lines
12 KiB
Python
359 lines
12 KiB
Python
# SPDX-License-Identifier: Apache-2.0
|
|
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
|
|
"""Benchmark and regression-test pinned (page-locked) CPU memory for vLLM.
|
|
|
|
Verifies that enabling pinned memory does not regress throughput or latency
|
|
compared to unpinned memory. Each condition runs in an isolated ``spawn``
|
|
subprocess so both start from a cold CUDA context, giving an unbiased
|
|
comparison.
|
|
|
|
Usage
|
|
-----
|
|
Run all tests with the default model::
|
|
|
|
python benchmarks/benchmark_pin_memory.py -v
|
|
|
|
Override the model and optional max-model-len::
|
|
|
|
python benchmarks/benchmark_pin_memory.py --model unsloth/Qwen3-1.7B -v
|
|
python benchmarks/benchmark_pin_memory.py --model unsloth/Qwen3-1.7B \
|
|
--max-model-len 8192 -v
|
|
|
|
Run only throughput or latency tests::
|
|
|
|
python benchmarks/benchmark_pin_memory.py -v -k test_throughput
|
|
python benchmarks/benchmark_pin_memory.py -v -k test_latency
|
|
|
|
Run only the v1 or v2 runner variant::
|
|
|
|
python benchmarks/benchmark_pin_memory.py -v -k v1
|
|
python benchmarks/benchmark_pin_memory.py -v -k v2
|
|
|
|
Note: on WSL2, v1 runner tests are skipped because pin memory is not available
|
|
for the v1 runner without cpu_offload_gb. Run on other platforms to exercise v1.
|
|
"""
|
|
|
|
import argparse
|
|
import json
|
|
import multiprocessing
|
|
import sys
|
|
import tempfile
|
|
|
|
import pytest
|
|
|
|
# Allow up to 2% degradation. Both benchmark runs start from an identical
|
|
# cold CUDA context (separate spawn subprocesses), so the measured difference
|
|
# reflects the genuine pin_memory overhead rather than cold/warm ordering bias.
|
|
_THROUGHPUT_TOLERANCE = 0.98
|
|
_THROUGHPUT_NUM_REQUESTS = 200
|
|
_THROUGHPUT_INPUT_LEN = 128
|
|
_THROUGHPUT_OUTPUT_LEN = 512
|
|
_THROUGHPUT_MAX_NUM_SEQS = 128
|
|
|
|
# Latency benchmark constants — match latency.py defaults.
|
|
_LATENCY_TOLERANCE = 1.02 # Allow up to 2% latency regression.
|
|
_LATENCY_BATCH_SIZE = 64
|
|
_LATENCY_INPUT_LEN = 32
|
|
_LATENCY_OUTPUT_LEN = 128
|
|
_LATENCY_WARMUP_ITERS = 5
|
|
_LATENCY_BENCH_ITERS = 15
|
|
|
|
_DEFAULT_MODEL = "unsloth/Qwen3-1.7B"
|
|
_DEFAULT_MAX_MODEL_LEN = 16384
|
|
|
|
|
|
def _benchmark_args() -> argparse.Namespace:
|
|
parser = argparse.ArgumentParser(add_help=False)
|
|
parser.add_argument("--model", default=_DEFAULT_MODEL)
|
|
parser.add_argument("--max-model-len", type=int, default=_DEFAULT_MAX_MODEL_LEN)
|
|
args, _ = parser.parse_known_args()
|
|
return args
|
|
|
|
|
|
@pytest.fixture
|
|
def model() -> str:
|
|
return _benchmark_args().model
|
|
|
|
|
|
@pytest.fixture
|
|
def max_model_len() -> int:
|
|
return _benchmark_args().max_model_len
|
|
|
|
|
|
def _skip_if_pin_memory_not_available(engine_args_kwargs: dict) -> None:
|
|
"""Skip the current pytest test if pin_memory is unavailable for this config."""
|
|
import vllm.utils.platform_utils as pu
|
|
from vllm.config import set_current_vllm_config
|
|
from vllm.engine.arg_utils import EngineArgs
|
|
|
|
vllm_config = EngineArgs(**engine_args_kwargs).create_engine_config()
|
|
with set_current_vllm_config(vllm_config):
|
|
pu.is_pin_memory_available.cache_clear()
|
|
if not pu.is_pin_memory_available():
|
|
import os
|
|
|
|
runner = "v2" if os.environ.get("VLLM_USE_V2_MODEL_RUNNER") == "1" else "v1"
|
|
model = engine_args_kwargs.get("model", "unknown")
|
|
print(
|
|
f"\033[33mSKIP: pin_memory not available for "
|
|
f"{runner} runner, model={model}\033[0m"
|
|
)
|
|
pytest.skip("pin_memory not available for this configuration")
|
|
|
|
|
|
def _throughput_worker(
|
|
pin: bool,
|
|
engine_args_kwargs: dict,
|
|
q: "multiprocessing.Queue[float]",
|
|
v2_mode: bool = False,
|
|
) -> None:
|
|
"""Run throughput benchmark in a fresh spawn subprocess.
|
|
|
|
Delegates to vllm/benchmarks/throughput.py main() using the random dataset,
|
|
so the methodology matches the official benchmark. Results are written to a
|
|
temp JSON file and forwarded through the queue as tokens/s.
|
|
|
|
v2_mode: when True, monkeypatches is_uva_available() to always return True
|
|
so the v2 model runner's UVA buffers remain functional even when pin=False.
|
|
This isolates the non-UVA pin_memory paths in v2.
|
|
"""
|
|
import vllm.utils.platform_utils as pu
|
|
from vllm.platforms import current_platform
|
|
|
|
pu.is_pin_memory_available.cache_clear()
|
|
pu.is_uva_available.cache_clear()
|
|
type(current_platform).is_pin_memory_available = classmethod(lambda cls: pin)
|
|
if v2_mode:
|
|
pu.is_uva_available = lambda: True
|
|
|
|
from vllm.benchmarks.throughput import add_cli_args
|
|
from vllm.benchmarks.throughput import main as throughput_main
|
|
|
|
parser = argparse.ArgumentParser()
|
|
add_cli_args(parser)
|
|
args = parser.parse_args([])
|
|
|
|
for key, val in engine_args_kwargs.items():
|
|
setattr(args, key, val)
|
|
args.max_num_seqs = _THROUGHPUT_MAX_NUM_SEQS
|
|
args.dataset_name = "random"
|
|
args.input_len = _THROUGHPUT_INPUT_LEN
|
|
args.output_len = _THROUGHPUT_OUTPUT_LEN
|
|
# Nullify defaults that conflict with explicit input/output_len.
|
|
args.random_input_len = None
|
|
args.random_output_len = None
|
|
args.random_prefix_len = None
|
|
args.num_prompts = _THROUGHPUT_NUM_REQUESTS
|
|
args.seed = 0
|
|
args.disable_detokenize = True
|
|
|
|
with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
|
|
tmp_path = f.name
|
|
args.output_json = tmp_path
|
|
|
|
throughput_main(args)
|
|
|
|
with open(tmp_path) as f:
|
|
results = json.load(f)
|
|
q.put(results["tokens_per_second"])
|
|
|
|
|
|
def _run_throughput_benchmark(
|
|
pin: bool,
|
|
engine_args_kwargs: dict,
|
|
v2_mode: bool = False,
|
|
) -> float:
|
|
ctx = multiprocessing.get_context("spawn")
|
|
q = ctx.Queue()
|
|
p = ctx.Process(
|
|
target=_throughput_worker,
|
|
args=(pin, engine_args_kwargs, q, v2_mode),
|
|
)
|
|
p.start()
|
|
p.join()
|
|
if p.exitcode != 0:
|
|
raise RuntimeError(
|
|
f"Throughput benchmark subprocess (pin={pin}) exited with code {p.exitcode}"
|
|
)
|
|
return q.get()
|
|
|
|
|
|
def _latency_worker(
|
|
pin: bool,
|
|
engine_args_kwargs: dict,
|
|
q: "multiprocessing.Queue[dict]",
|
|
v2_mode: bool = False,
|
|
) -> None:
|
|
"""Run latency benchmark in a fresh spawn subprocess.
|
|
|
|
Follows latency.py methodology: fixed batch of dummy token IDs, warmup
|
|
iterations to reach steady state, then timed iterations reduced to avg
|
|
and percentiles. Results are written to a temp JSON file by latency_main
|
|
and forwarded through the queue.
|
|
"""
|
|
import vllm.utils.platform_utils as pu
|
|
from vllm.platforms import current_platform
|
|
|
|
pu.is_pin_memory_available.cache_clear()
|
|
pu.is_uva_available.cache_clear()
|
|
type(current_platform).is_pin_memory_available = classmethod(lambda cls: pin)
|
|
if v2_mode:
|
|
pu.is_uva_available = lambda: True
|
|
|
|
from vllm.benchmarks.latency import add_cli_args
|
|
from vllm.benchmarks.latency import main as latency_main
|
|
|
|
parser = argparse.ArgumentParser()
|
|
add_cli_args(parser)
|
|
args = parser.parse_args([])
|
|
|
|
for key, val in engine_args_kwargs.items():
|
|
setattr(args, key, val)
|
|
args.input_len = _LATENCY_INPUT_LEN
|
|
args.output_len = _LATENCY_OUTPUT_LEN
|
|
args.batch_size = _LATENCY_BATCH_SIZE
|
|
args.num_iters_warmup = _LATENCY_WARMUP_ITERS
|
|
args.num_iters = _LATENCY_BENCH_ITERS
|
|
args.profile = False
|
|
args.disable_detokenize = True
|
|
|
|
with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
|
|
tmp_path = f.name
|
|
args.output_json = tmp_path
|
|
|
|
latency_main(args)
|
|
|
|
with open(tmp_path) as f:
|
|
results = json.load(f)
|
|
q.put(results)
|
|
|
|
|
|
def _run_latency_benchmark(
|
|
pin: bool,
|
|
engine_args_kwargs: dict,
|
|
v2_mode: bool = False,
|
|
) -> dict:
|
|
ctx = multiprocessing.get_context("spawn")
|
|
q = ctx.Queue()
|
|
p = ctx.Process(
|
|
target=_latency_worker,
|
|
args=(pin, engine_args_kwargs, q, v2_mode),
|
|
)
|
|
p.start()
|
|
p.join()
|
|
if p.exitcode != 0:
|
|
raise RuntimeError(
|
|
f"Latency benchmark subprocess (pin={pin}) exited with code {p.exitcode}"
|
|
)
|
|
return q.get()
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"test_v2_runner",
|
|
[
|
|
pytest.param(False, id="v1"),
|
|
pytest.param(True, id="v2"),
|
|
],
|
|
)
|
|
class TestPinnedMemory:
|
|
"""Verify pinned memory yields >= throughput vs unpinned via real vLLM inference."""
|
|
|
|
def test_throughput(self, monkeypatch, test_v2_runner, model, max_model_len):
|
|
"""Benchmark throughput with pin_memory forced on then off.
|
|
|
|
Delegates to vllm/benchmarks/throughput.py main() with the random
|
|
dataset. Each condition runs in an isolated spawn subprocess so both
|
|
start from a cold CUDA context, giving an unbiased comparison.
|
|
"""
|
|
monkeypatch.setenv("VLLM_ENABLE_V1_MULTIPROCESSING", "0")
|
|
monkeypatch.setenv("VLLM_USE_V2_MODEL_RUNNER", "1" if test_v2_runner else "0")
|
|
|
|
engine_args_kwargs = dict(
|
|
model=model,
|
|
gpu_memory_utilization=0.88,
|
|
max_model_len=max_model_len,
|
|
enable_prefix_caching=False,
|
|
)
|
|
|
|
_skip_if_pin_memory_not_available(engine_args_kwargs)
|
|
|
|
unpinned_tps = _run_throughput_benchmark(
|
|
False, engine_args_kwargs, v2_mode=test_v2_runner
|
|
)
|
|
pinned_tps = _run_throughput_benchmark(
|
|
True, engine_args_kwargs, v2_mode=test_v2_runner
|
|
)
|
|
|
|
pct_diff = (pinned_tps - unpinned_tps) / unpinned_tps * 100
|
|
runner = "v2" if test_v2_runner else "v1"
|
|
print(
|
|
f"\n=== Throughput results ({runner} runner, {model}) ==="
|
|
f"\npin_memory=True: {pinned_tps:.1f} tok/s"
|
|
f"\npin_memory=False: {unpinned_tps:.1f} tok/s"
|
|
f"\nDifference: {pct_diff:+.1f}% (pinned vs unpinned)"
|
|
)
|
|
|
|
assert pinned_tps >= unpinned_tps * _THROUGHPUT_TOLERANCE, (
|
|
f"Pinned throughput ({pinned_tps:.1f} tok/s) fell more than "
|
|
f"{(1.0 - _THROUGHPUT_TOLERANCE) * 100:.1f}% below "
|
|
f"unpinned ({unpinned_tps:.1f} tok/s)."
|
|
)
|
|
|
|
def test_latency(self, monkeypatch, test_v2_runner, model, max_model_len):
|
|
"""Benchmark per-batch latency with pin_memory forced on then off.
|
|
|
|
Follows vllm/benchmarks/latency.py: fixed dummy-token batch, warmup
|
|
iterations to reach steady state, then timed iterations reduced to avg
|
|
and percentiles. Subprocesses run serially so each gets a cold CUDA
|
|
context without GPU memory pressure from the other run.
|
|
"""
|
|
monkeypatch.setenv("VLLM_ENABLE_V1_MULTIPROCESSING", "0")
|
|
monkeypatch.setenv("VLLM_USE_V2_MODEL_RUNNER", "1" if test_v2_runner else "0")
|
|
|
|
engine_args_kwargs = dict(
|
|
model=model,
|
|
gpu_memory_utilization=0.88,
|
|
max_model_len=max_model_len,
|
|
enable_prefix_caching=False,
|
|
)
|
|
|
|
_skip_if_pin_memory_not_available(engine_args_kwargs)
|
|
|
|
unpinned = _run_latency_benchmark(
|
|
False, engine_args_kwargs, v2_mode=test_v2_runner
|
|
)
|
|
pinned = _run_latency_benchmark(
|
|
True, engine_args_kwargs, v2_mode=test_v2_runner
|
|
)
|
|
|
|
pct_diff = (
|
|
(pinned["avg_latency"] - unpinned["avg_latency"])
|
|
/ unpinned["avg_latency"]
|
|
* 100
|
|
)
|
|
runner = "v2" if test_v2_runner else "v1"
|
|
print(
|
|
f"\n=== Latency results ({runner} runner, {model}) ==="
|
|
f"\npin_memory=True: avg={pinned['avg_latency']:.3f}s"
|
|
f" p50={pinned['percentiles']['50']:.3f}s"
|
|
f" p99={pinned['percentiles']['99']:.3f}s"
|
|
f"\npin_memory=False: avg={unpinned['avg_latency']:.3f}s"
|
|
f" p50={unpinned['percentiles']['50']:.3f}s"
|
|
f" p99={unpinned['percentiles']['99']:.3f}s"
|
|
f"\nDifference: {pct_diff:+.1f}% (pinned vs unpinned)"
|
|
)
|
|
|
|
assert pinned["avg_latency"] <= unpinned["avg_latency"] * _LATENCY_TOLERANCE, (
|
|
f"Pinned avg latency ({pinned['avg_latency']:.3f}s) exceeded "
|
|
f"unpinned ({unpinned['avg_latency']:.3f}s) by more than "
|
|
f"{(_LATENCY_TOLERANCE - 1.0) * 100:.1f}%."
|
|
)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
_parser = argparse.ArgumentParser(add_help=False)
|
|
_parser.add_argument("--model", default=_DEFAULT_MODEL)
|
|
_parser.add_argument("--max-model-len", type=int, default=_DEFAULT_MAX_MODEL_LEN)
|
|
_, _remaining = _parser.parse_known_args()
|
|
sys.exit(pytest.main([__file__] + _remaining))
|