Files
sglang/sgl-model-gateway/e2e_test/infra/gpu_monitor.py

330 lines
9.7 KiB
Python

"""GPU utilization monitoring for benchmarks.
This module provides a low-impact GPU monitor that runs in a separate process
and collects utilization samples using NVML.
"""
from __future__ import annotations
import json
import logging
import os
import time
from multiprocessing import Process
from pathlib import Path
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from typing import Any
logger = logging.getLogger(__name__)
def _percentile(samples: list[float], p: float) -> float:
"""Calculate percentile from sorted samples."""
if not samples:
return 0.0
sorted_samples = sorted(samples)
idx = max(
0,
min(
len(sorted_samples) - 1, int(round((p / 100.0) * (len(sorted_samples) - 1)))
),
)
return float(sorted_samples[idx])
def _compute_stats(samples: list[float]) -> dict[str, float]:
"""Compute statistics for a list of samples."""
if not samples:
return {
"mean": 0.0,
"min": 0.0,
"max": 0.0,
"p5": 0.0,
"p10": 0.0,
"p25": 0.0,
"p50": 0.0,
"p75": 0.0,
"p90": 0.0,
"p95": 0.0,
"count": 0,
}
return {
"mean": sum(samples) / len(samples),
"min": min(samples),
"max": max(samples),
"p5": _percentile(samples, 5),
"p10": _percentile(samples, 10),
"p25": _percentile(samples, 25),
"p50": _percentile(samples, 50),
"p75": _percentile(samples, 75),
"p90": _percentile(samples, 90),
"p95": _percentile(samples, 95),
"count": len(samples),
}
def _monitor_loop(pid: int, output_path: str, interval: float) -> None:
"""Main monitoring loop - runs in separate process.
Monitors GPU utilization until the target process exits, then writes
results to output_path as JSON.
"""
# Lower process priority to minimize impact on benchmark
try:
os.nice(10)
except Exception:
pass
# Initialize NVML
try:
import pynvml
pynvml.nvmlInit()
except Exception as e:
logger.warning("Failed to initialize NVML: %s", e)
_write_empty_result(output_path)
return
# Get GPU handles
try:
device_count = pynvml.nvmlDeviceGetCount()
handles = [pynvml.nvmlDeviceGetHandleByIndex(i) for i in range(device_count)]
except Exception as e:
logger.warning("Failed to get GPU handles: %s", e)
_write_empty_result(output_path)
_shutdown_nvml()
return
# Collect samples
per_gpu_samples: dict[str, list[float]] = {str(i): [] for i in range(device_count)}
overall_samples: list[float] = []
try:
while _process_alive(pid):
try:
gpu_utils = []
for idx, handle in enumerate(handles):
try:
util = pynvml.nvmlDeviceGetUtilizationRates(handle).gpu
gpu_utils.append(float(util))
per_gpu_samples[str(idx)].append(float(util))
except Exception:
continue
if gpu_utils:
avg = sum(gpu_utils) / len(gpu_utils)
overall_samples.append(avg)
except Exception:
pass
time.sleep(interval)
finally:
# Write results
_write_result(output_path, pid, interval, overall_samples, per_gpu_samples)
_shutdown_nvml()
def _process_alive(pid: int) -> bool:
"""Check if process is still running."""
try:
os.kill(pid, 0)
return True
except (OSError, ProcessLookupError):
return False
def _write_empty_result(path: str) -> None:
"""Write empty result file."""
try:
os.makedirs(os.path.dirname(path), exist_ok=True)
with open(path, "w") as f:
json.dump(
{
"count": 0,
"overall": {"mean": 0.0},
"per_gpu": {},
"raw": {"overall": [], "per_gpu": {}},
},
f,
)
except Exception:
pass
def _write_result(
path: str,
pid: int,
interval: float,
overall_samples: list[float],
per_gpu_samples: dict[str, list[float]],
) -> None:
"""Write monitoring results to JSON file."""
try:
os.makedirs(os.path.dirname(path), exist_ok=True)
with open(path, "w") as f:
json.dump(
{
"bench_pid": pid,
"interval_sec": interval,
"count": len(overall_samples),
"overall": _compute_stats(overall_samples),
"per_gpu": {
k: _compute_stats(v) for k, v in per_gpu_samples.items()
},
"raw": {
"overall": overall_samples,
"per_gpu": per_gpu_samples,
},
},
f,
)
except Exception as e:
logger.warning("Failed to write GPU monitor results: %s", e)
def _shutdown_nvml() -> None:
"""Shutdown NVML."""
try:
import pynvml
pynvml.nvmlShutdown()
except Exception:
pass
class GPUMonitor:
"""GPU utilization monitor for benchmarks.
Usage:
monitor = GPUMonitor(output_dir="benchmark_results")
monitor.start(target_pid=12345)
# ... run benchmark ...
result = monitor.stop()
monitor.assert_thresholds({"gpu_util_p50_min": 99})
"""
def __init__(
self,
output_dir: str | Path = ".",
interval: float = 2.0,
):
self.output_dir = Path(output_dir)
self.interval = interval
self._process: Process | None = None
self._output_path: str | None = None
self._result: dict[str, Any] | None = None
@property
def output_path(self) -> str | None:
"""Path to the GPU utilization JSON file."""
return self._output_path
def start(self, target_pid: int) -> None:
"""Start monitoring GPU utilization for the target process."""
self._output_path = str(self.output_dir / "gpu_utilization.json")
self._result = None
self._process = Process(
target=_monitor_loop,
args=(target_pid, self._output_path, self.interval),
daemon=True,
)
self._process.start()
logger.debug("Started GPU monitor for PID %d", target_pid)
def stop(self, timeout: float = 5.0) -> dict[str, Any] | None:
"""Stop monitoring and return results."""
if self._process is None:
return None
try:
self._process.join(timeout=timeout)
except Exception:
pass
if self._process.is_alive():
try:
self._process.terminate()
except Exception:
pass
self._process = None
self._result = self._read_result()
return self._result
def _read_result(self) -> dict[str, Any] | None:
"""Read results from output file."""
if not self._output_path or not os.path.exists(self._output_path):
return None
try:
with open(self._output_path) as f:
return json.load(f)
except Exception as e:
logger.warning("Failed to read GPU monitor result: %s", e)
return None
def log_summary(self) -> None:
"""Log a summary of GPU utilization."""
result = self._result or self._read_result()
if not result or result.get("count", 0) <= 0:
logger.warning("GPU utilization monitor produced no samples")
return
overall = result.get("overall", {})
logger.info(
"GPU utilization: mean=%.2f%% p50=%.2f%% (samples=%d)",
overall.get("mean", 0.0),
overall.get("p50", 0.0),
result.get("count", 0),
)
def assert_thresholds(self, thresholds: dict[str, float] | None) -> None:
"""Assert GPU utilization meets thresholds.
Supported thresholds:
- gpu_util_mean_min: Minimum mean GPU utilization %
- gpu_util_p50_min: Minimum p50 GPU utilization %
"""
if not thresholds:
return
result = self._result or self._read_result()
if not result or result.get("count", 0) <= 0:
logger.warning("GPU utilization monitor produced no samples")
return
overall = result.get("overall", {})
mean_threshold = thresholds.get("gpu_util_mean_min")
if mean_threshold is not None:
mean_value = overall.get("mean", 0.0)
assert (
mean_value >= mean_threshold
), f"GPU utilization mean below threshold: {mean_value:.2f}% < {mean_threshold}%"
p50_threshold = thresholds.get("gpu_util_p50_min")
if p50_threshold is not None:
p50_value = overall.get("p50")
if p50_value is not None:
assert (
p50_value >= p50_threshold
), f"GPU utilization p50 below threshold: {p50_value:.2f}% < {p50_threshold}%"
def should_monitor(thresholds: dict[str, Any] | None) -> bool:
"""Check if GPU monitoring should be enabled.
Returns True if:
- thresholds contains gpu_util_mean_min or gpu_util_p50_min, OR
- GPU_UTIL_LOG environment variable is truthy
"""
if thresholds:
if thresholds.get("gpu_util_mean_min") is not None:
return True
if thresholds.get("gpu_util_p50_min") is not None:
return True
return os.environ.get("GPU_UTIL_LOG", "").lower() in ("1", "true", "yes")