Rewrite intel GPU stats to use file descriptors instead of intel_gpu_top, leading to significantly better API for interaction and more accurate results

This commit is contained in:
Nicolas Mowen 2026-05-04 08:51:31 -06:00
parent 814c497bef
commit 286144deb4

View File

@ -264,154 +264,208 @@ def get_amd_gpu_stats() -> Optional[dict[str, str]]:
return results return results
def get_intel_gpu_stats(intel_gpu_device: Optional[str]) -> Optional[dict[str, str]]: _INTEL_FDINFO_SAMPLE_SECONDS = 1.0
"""Get stats using intel_gpu_top.
Returns overall GPU usage derived from rc6 residency (idle time), # i915 fdinfo keys (cumulative ns) → logical engine name.
plus individual engine breakdowns: _I915_ENGINE_KEYS = {
- enc: Render/3D engine (compute/shader encoder, used by QSV) "drm-engine-render": "render",
- dec: Video engines (fixed-function codec, used by VAAPI) "drm-engine-video": "video",
"drm-engine-video-enhance": "video-enhance",
"drm-engine-compute": "compute",
"drm-engine-copy": "copy",
}
# Xe fdinfo suffixes (cumulative cycles, paired with drm-total-cycles-*).
_XE_ENGINE_KEYS = {
"rcs": "render",
"vcs": "video",
"vecs": "video-enhance",
"ccs": "compute",
"bcs": "copy",
}
def _resolve_intel_gpu_pdev(device: Optional[str]) -> Optional[str]:
"""Map a configured GPU hint (/dev/dri/card1, renderD128, or a PCI bus
address) to its drm-pdev string so we can filter fdinfo entries to that
device. Returns None when no hint is supplied or it cannot be resolved."""
if not device:
return None
if re.match(r"^[0-9a-fA-F]{4}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}\.[0-9a-fA-F]$", device):
return device
name = os.path.basename(device.rstrip("/"))
try:
return os.path.basename(os.path.realpath(f"/sys/class/drm/{name}/device"))
except OSError:
return None
def _read_intel_drm_fdinfo(target_pdev: Optional[str]) -> dict:
"""Snapshot DRM fdinfo for every Intel client visible in /proc.
Returns a dict keyed by (pdev, drm-client-id, pid) so the same context
seen via multiple file descriptors on a single process collapses to one
entry.
""" """
snapshot: dict = {}
def get_stats_manually(output: str) -> dict[str, str]:
"""Find global stats via regex when json fails to parse."""
reading = "".join(output)
results: dict[str, str] = {}
# rc6 residency for overall GPU usage
rc6_match = re.search(r'"rc6":\{"value":([\d.]+)', reading)
if rc6_match:
rc6_value = float(rc6_match.group(1))
results["gpu"] = f"{round(100.0 - rc6_value, 2)}%"
else:
results["gpu"] = "-%"
results["mem"] = "-%"
# Render/3D is the compute/encode engine
render = []
for result in re.findall(r'"Render/3D/0":{[a-z":\d.,%]+}', reading):
packet = json.loads(result[14:])
single = packet.get("busy", 0.0)
render.append(float(single))
if render:
results["compute"] = f"{round(sum(render) / len(render), 2)}%"
# Video engines are the fixed-function decode engines
video = []
for result in re.findall(r'"Video/\d":{[a-z":\d.,%]+}', reading):
packet = json.loads(result[10:])
single = packet.get("busy", 0.0)
video.append(float(single))
if video:
results["dec"] = f"{round(sum(video) / len(video), 2)}%"
return results
intel_gpu_top_command = [
"timeout",
"0.5s",
"intel_gpu_top",
"-J",
"-o",
"-",
"-s",
"1000", # Intel changed this from seconds to milliseconds in 2024+ versions
]
if intel_gpu_device:
intel_gpu_top_command += ["-d", intel_gpu_device]
try: try:
p = sp.run( proc_entries = os.listdir("/proc")
intel_gpu_top_command, except OSError:
encoding="ascii", return snapshot
capture_output=True,
)
except UnicodeDecodeError:
return None
# timeout has a non-zero returncode when timeout is reached for entry in proc_entries:
if p.returncode != 124: if not entry.isdigit():
logger.error(f"Unable to poll intel GPU stats: {p.stderr}") continue
return None
else:
output = "".join(p.stdout.split())
fdinfo_dir = f"/proc/{entry}/fdinfo"
try: try:
data = json.loads(f"[{output}]") fds = os.listdir(fdinfo_dir)
except json.JSONDecodeError: except (FileNotFoundError, PermissionError, NotADirectoryError, OSError):
return get_stats_manually(output) continue
results: dict[str, str] = {} for fd in fds:
rc6_values = [] try:
render_global = [] with open(f"{fdinfo_dir}/{fd}") as f:
video_global = [] content = f.read()
# per-client: {pid: [total_busy_per_sample, ...]} except (FileNotFoundError, PermissionError, OSError):
client_usages: dict[str, list[float]] = {} continue
for block in data: if "drm-driver" not in content:
# rc6 residency: percentage of time GPU is idle continue
rc6 = block.get("rc6", {}).get("value")
if rc6 is not None:
rc6_values.append(float(rc6))
global_engine = block.get("engines") fields: dict[str, str] = {}
for line in content.splitlines():
key, sep, value = line.partition(":")
if sep:
fields[key.strip()] = value.strip()
if global_engine: driver = fields.get("drm-driver")
render_frame = global_engine.get("Render/3D/0", {}).get("busy") if driver not in ("i915", "xe"):
video_frame = global_engine.get("Video/0", {}).get("busy") continue
if render_frame is not None: pdev = fields.get("drm-pdev", "")
render_global.append(float(render_frame)) if target_pdev and pdev != target_pdev:
continue
if video_frame is not None: client_id = fields.get("drm-client-id")
video_global.append(float(video_frame)) if not client_id:
continue
clients = block.get("clients", {}) key = (pdev, client_id, entry)
if key in snapshot:
continue
if clients: engines: dict[str, tuple[int, int]] = {}
for client_block in clients.values():
pid = client_block["pid"]
if pid not in client_usages: if driver == "i915":
client_usages[pid] = [] for fkey, engine in _I915_ENGINE_KEYS.items():
raw = fields.get(fkey)
# Sum all engine-class busy values for this client if not raw:
total_busy = 0.0 continue
for engine in client_block.get("engine-classes", {}).values(): try:
busy = engine.get("busy") engines[engine] = (int(raw.split()[0]), 0)
if busy is not None: except (ValueError, IndexError):
total_busy += float(busy) continue
else:
client_usages[pid].append(total_busy) for suffix, engine in _XE_ENGINE_KEYS.items():
busy_raw = fields.get(f"drm-cycles-{suffix}")
# Overall GPU usage from rc6 (idle) residency total_raw = fields.get(f"drm-total-cycles-{suffix}")
if rc6_values: if not (busy_raw and total_raw):
rc6_avg = sum(rc6_values) / len(rc6_values) continue
results["gpu"] = f"{round(100.0 - rc6_avg, 2)}%" try:
engines[engine] = (
results["mem"] = "-%" int(busy_raw.split()[0]),
int(total_raw.split()[0]),
# Compute: Render/3D engine (compute/shader workloads and QSV encode)
if render_global:
results["compute"] = f"{round(sum(render_global) / len(render_global), 2)}%"
# Decoder: Video engine (fixed-function codec)
if video_global:
results["dec"] = f"{round(sum(video_global) / len(video_global), 2)}%"
# Per-client GPU usage (sum of all engines per process)
if client_usages:
results["clients"] = {}
for pid, samples in client_usages.items():
if samples:
results["clients"][pid] = (
f"{round(sum(samples) / len(samples), 2)}%"
) )
except (ValueError, IndexError):
continue
if not engines:
continue
snapshot[key] = {"driver": driver, "pid": entry, "engines": engines}
return snapshot
def get_intel_gpu_stats(intel_gpu_device: Optional[str]) -> Optional[dict[str, Any]]:
"""Get stats by reading DRM fdinfo files.
Each DRM client FD exposes monotonic per-engine busy counters via
/proc/<pid>/fdinfo/<fd> (i915 since kernel 5.19, Xe since first release).
We sample twice and divide busy-time deltas by wall-clock to derive
utilisation. Render/3D and the dedicated Compute engine are pooled into
"compute"; Video into "dec".
"""
target_pdev = _resolve_intel_gpu_pdev(intel_gpu_device)
snapshot_a = _read_intel_drm_fdinfo(target_pdev)
if not snapshot_a:
return None
start = time.monotonic()
time.sleep(_INTEL_FDINFO_SAMPLE_SECONDS)
elapsed_ns = (time.monotonic() - start) * 1e9
snapshot_b = _read_intel_drm_fdinfo(target_pdev)
if not snapshot_b or elapsed_ns <= 0:
return None
engine_pct: dict[str, float] = {
"render": 0.0,
"video": 0.0,
"video-enhance": 0.0,
"compute": 0.0,
"copy": 0.0,
}
pid_pct: dict[str, float] = {}
for key, data_b in snapshot_b.items():
data_a = snapshot_a.get(key)
if not data_a or data_a["driver"] != data_b["driver"]:
continue
client_total = 0.0
for engine, (busy_b, total_b) in data_b["engines"].items():
busy_a, total_a = data_a["engines"].get(engine, (busy_b, total_b))
if data_b["driver"] == "i915":
delta = max(0, busy_b - busy_a)
pct = min(100.0, delta / elapsed_ns * 100.0)
else:
delta_busy = max(0, busy_b - busy_a)
delta_total = total_b - total_a
if delta_total <= 0:
continue
pct = min(100.0, delta_busy / delta_total * 100.0)
engine_pct[engine] += pct
client_total += pct
pid_pct[data_b["pid"]] = pid_pct.get(data_b["pid"], 0.0) + client_total
for engine in engine_pct:
engine_pct[engine] = min(100.0, engine_pct[engine])
compute_pct = min(100.0, engine_pct["render"] + engine_pct["compute"])
dec_pct = engine_pct["video"]
overall_pct = max(
compute_pct, dec_pct, engine_pct["video-enhance"], engine_pct["copy"]
)
results: dict[str, Any] = {
"gpu": f"{round(overall_pct, 2)}%",
"mem": "-%",
"compute": f"{round(compute_pct, 2)}%",
"dec": f"{round(dec_pct, 2)}%",
}
if pid_pct:
results["clients"] = {
pid: f"{round(min(100.0, pct), 2)}%" for pid, pct in pid_pct.items()
}
return results return results