Files
lidar_rendu/lidar_pipeline/gpu.py
Antoine Jacquin 8478106e51 Fix GPU bugs, restore aspect viz, fix anomaly mask, revert flow_acc to vectorized D8
GPU: num_gpus() returns real count via _gpu_candidates (was always 0/1),
available_gpu_ids() added. Pipeline: round-robin on real GPU host indices
instead of file enumerate index. _process_file_standalone signature simplified.

Restore generate_aspect using SharedDEM gradient (dy, dx). Colormap twilight
0-360 fixed range. VIZ_STEPS back to 16.

Flow accumulation: revert to vectorized numpy D8 direction + module-level
numba accumulator (cached, top-down sort) with Python fallback. Priority-flood
NaN-aware. Log1p transform.

Anomaly mask: replace RMS+fixed 2sigma threshold (was blank) with weighted
sum of |z-score| + adaptive percentile threshold. Absolute z-score captures
both positive and negative deviations. 6% signal detected vs 0% before.
2026-06-01 23:03:19 +02:00

390 lines
13 KiB
Python

"""GPU acceleration helpers for LiDAR pipeline.
Auto-selects the best NVIDIA GPU (highest compute capability first).
Uses CuPy Device API (not CUDA_VISIBLE_DEVICES) so JIT compilation
works correctly for any architecture (sm_89, sm_120, etc.).
All workers share the selected GPU.
"""
import logging
import os
import numpy as np
from scipy import ndimage
logger = logging.getLogger("lidar")
# ---------------------------------------------------------------------------
# GPU auto-detection via nvidia-smi (no CUDA context created)
# ---------------------------------------------------------------------------
_NUM_GPUS = 0
HAS_GPU = False
_gpu_name = None
_gpu_mem_gb = 0
_best_gpu_id: int | None = None
_gpu_reason = None
# GPU restriction from -g flag (host-level indices)
_restricted_gpu_ids: list[int] | None = None
# Discovered GPU candidates (populated by _pick_gpu)
_gpu_candidates: list[dict] = []
def _pick_gpu() -> list:
"""List all GPUs from the system, sorted by compute capability (highest first)."""
try:
import subprocess
result = subprocess.run(
['nvidia-smi', '--query-gpu=index,name,compute_cap,memory.total',
'--format=csv,noheader,nounits'],
capture_output=True, text=True, timeout=5,
)
if result.returncode != 0:
return []
global _NUM_GPUS
gpus = []
for line in result.stdout.strip().split('\n'):
parts = [p.strip() for p in line.split(',')]
if len(parts) < 4:
continue
idx = int(parts[0])
name = parts[1]
cap_str = parts[2]
mem_mi = int(parts[3])
major, minor = (int(x) for x in cap_str.split('.'))
score = major * 1000 + minor * 100 + mem_mi
gpus.append((idx, name, cap_str, mem_mi, score, major))
_NUM_GPUS = len(gpus)
gpus.sort(key=lambda g: g[4], reverse=True)
return gpus
except (FileNotFoundError, subprocess.TimeoutExpired, Exception):
return []
_candidate_gpus: list = []
try:
_candidate_gpus = _pick_gpu() or []
except Exception:
pass
# ---------------------------------------------------------------------------
# Lazy CuPy initialization — tries each GPU until one works
# ---------------------------------------------------------------------------
_xp = np
_cp = None
_cp_ndimage = None
_gpu_initialized = False
def _filter_candidates(gpus: list) -> list:
"""Filter GPU candidates by CUDA_VISIBLE_DEVICES and _restricted_gpu_ids.
nvidia-smi lists ALL GPUs even when CUDA_VISIBLE_DEVICES is set
(driver 580.x behavior), so we must filter manually.
"""
# Filter by CUDA_VISIBLE_DEVICES if set
cuda_visible = os.environ.get('CUDA_VISIBLE_DEVICES')
if cuda_visible is not None:
try:
visible = {int(i.strip()) for i in cuda_visible.split(',')}
gpus = [g for g in gpus if g[0] in visible]
except ValueError:
pass
# Filter by programmatic restriction (-g 0, -g 0,2)
if _restricted_gpu_ids is not None:
allowed = set(_restricted_gpu_ids)
gpus = [g for g in gpus if g[0] in allowed]
return gpus
def _init_gpu():
"""Lazily initialize CuPy on first GPU use.
1. Filters candidates by CUDA_VISIBLE_DEVICES and _restricted_gpu_ids
2. If CUDA_VISIBLE_DEVICES is already set (e.g. run.sh -g 0):
import CuPy directly (no subprocess test needed)
3. Otherwise: test each GPU in a subprocess, pick the first that works
"""
global _xp, _cp, _cp_ndimage, _gpu_initialized, HAS_GPU, _best_gpu_id, _gpu_name, _gpu_mem_gb
if _gpu_initialized:
return
_gpu_initialized = True
candidates = _filter_candidates(_candidate_gpus)
if not candidates:
logger.info("Pas de GPU utilisable — mode CPU uniquement")
_xp = np
_cp = None
_cp_ndimage = None
HAS_GPU = False
return
cuda_visible = os.environ.get('CUDA_VISIBLE_DEVICES')
if cuda_visible is not None:
# CUDA_VISIBLE_DEVICES already set (e.g. by run.sh -g 0).
# Pick the best visible GPU and import CuPy directly.
idx, name, cap_str, mem_mi, score, major = candidates[0]
try:
import cupy as _real_cupy
import cupyx.scipy.ndimage as _real_cupy_ndimage
# Warm-up kernel to verify GPU works
x = _real_cupy.array([1.0, 2.0], dtype=_real_cupy.float32)
s = _real_cupy.sum(x).get()
if s != 3.0:
raise RuntimeError("GPU warm-up failed")
_best_gpu_id = idx
_gpu_name = name
_gpu_mem_gb = mem_mi // 1024
HAS_GPU = True
_xp = _real_cupy
_cp = _real_cupy
_cp_ndimage = _real_cupy_ndimage
return
except Exception as e:
logger.warning(f"GPU indisponible (CUDA_VISIBLE_DEVICES={cuda_visible}): {e}")
_xp = np
_cp = None
_cp_ndimage = None
HAS_GPU = False
return
# No CUDA_VISIBLE_DEVICES set — test each GPU in subprocess
import subprocess
_working_gpu = None
for idx, name, cap_str, mem_mi, score, major in candidates:
result = subprocess.run(
['python3', '-c',
'import cupy; a=cupy.array([1.0,2.0],dtype=cupy.float32); '
'dev=cupy.cuda.runtime.getDevice(); '
'print(f"OK:{dev}:{cupy.sum(a).get()}")'],
capture_output=True, text=True, timeout=120,
env={**os.environ, 'CUDA_VISIBLE_DEVICES': str(idx)},
)
stdout = result.stdout.strip()
if result.returncode == 0 and stdout.startswith('OK:') and '3.0' in stdout:
# Verify the device actually used is device 0 (the GPU we targeted)
parts = stdout.split(':')
if len(parts) >= 2 and parts[1] == '0':
_working_gpu = (idx, name, mem_mi)
break
else:
logger.warning(f"GPU {idx} ({name}, sm_{cap_str}) faux positif CPU fallback")
logger.warning(f"GPU {idx} ({name}, sm_{cap_str}) non compatible: "
f"{result.stderr.strip().splitlines()[-1] if result.stderr else 'inconnue'}")
if _working_gpu is None:
logger.info("Pas de GPU utilisable — mode CPU uniquement")
_xp = np
_cp = None
_cp_ndimage = None
HAS_GPU = False
return
idx, name, mem_mi = _working_gpu
os.environ['CUDA_VISIBLE_DEVICES'] = str(idx)
import cupy as _real_cupy
import cupyx.scipy.ndimage as _real_cupy_ndimage
_best_gpu_id = idx
_gpu_name = name
_gpu_mem_gb = mem_mi // 1024
HAS_GPU = True
_xp = _real_cupy
_cp = _real_cupy
_cp_ndimage = _real_cupy_ndimage
# ---------------------------------------------------------------------------
# Public API
# ---------------------------------------------------------------------------
def num_gpus():
"""Return the number of available GPUs (after restrict_gpus filtering)."""
return len(_gpu_candidates)
def available_gpu_ids():
"""Return list of host-level GPU indices available for processing.
Respects any prior restrict_gpus() call.
"""
return [c['id'] for c in _gpu_candidates]
def restrict_gpus(gpu_ids: list[int], set_env_var: bool = False):
"""Restrict GPU selection to specific host-level indices.
Stores the restriction to be applied during _init_gpu().
"""
global _restricted_gpu_ids
_restricted_gpu_ids = gpu_ids
def set_active_gpu(gpu_id):
"""Restrict to a single GPU by host-level index."""
global _restricted_gpu_ids
_restricted_gpu_ids = [gpu_id]
def _gpu_available():
"""Check if GPU is usable right now."""
try:
_init_gpu()
return HAS_GPU and _cp is not None
except Exception:
return False
def log_gpu_status():
"""Log GPU detection result. Called after logging is configured."""
if _gpu_available():
try:
with _cp.cuda.Device(_best_gpu_id):
name = _cp.cuda.runtime.getDeviceProperties(_best_gpu_id)['name']
if isinstance(name, bytes):
name = name.decode()
mem_gb = _cp.cuda.runtime.getDeviceProperties(_best_gpu_id)['totalGlobalMem'] // (1024**3)
gpu_info = f"GPU: {name} ({mem_gb} Go VRAM) — ID {_best_gpu_id}"
except Exception:
gpu_info = f"GPU: {_gpu_name} ({_gpu_mem_gb} Go VRAM)"
logger.info(gpu_info)
# List other GPUs for info
try:
import subprocess
result = subprocess.run(
['nvidia-smi', '--query-gpu=index,name,compute_cap',
'--format=csv,noheader,nounits'],
capture_output=True, text=True, timeout=5,
)
if result.returncode == 0:
for line in result.stdout.strip().split('\n'):
parts = [p.strip() for p in line.split(',')]
if len(parts) >= 3:
idx = int(parts[0])
if idx != _best_gpu_id:
cap = parts[2]
logger.info(f" GPU {idx}: {parts[1]} (sm_{cap}) — disponible")
except Exception:
pass
else:
logger.info(f"Pas de GPU utilisable — mode CPU uniquement")
# ---------------------------------------------------------------------------
# Array transfer
# ---------------------------------------------------------------------------
def to_gpu(arr):
"""Send array to GPU if available, otherwise return as float32 numpy."""
if _gpu_available():
try:
return _cp.asarray(arr.astype(np.float32))
except Exception:
disable_gpu()
return arr.astype(np.float32)
def to_cpu(arr):
"""Bring array back to CPU (numpy). No-op if already on CPU."""
if _cp is not None and isinstance(arr, _cp.ndarray):
try:
return _cp.asnumpy(arr)
except Exception:
pass
return arr
# ---------------------------------------------------------------------------
# Filters — GPU if array is on GPU, CPU otherwise
# ---------------------------------------------------------------------------
def xp_gaussian_filter(arr, sigma):
if _cp is not None and isinstance(arr, _cp.ndarray):
try:
return _cp_ndimage.gaussian_filter(arr, sigma)
except Exception:
arr = to_cpu(arr)
return ndimage.gaussian_filter(arr, sigma)
def xp_uniform_filter(arr, size):
if _cp is not None and isinstance(arr, _cp.ndarray):
try:
return _cp_ndimage.uniform_filter(arr, size)
except Exception:
arr = to_cpu(arr)
return ndimage.uniform_filter(arr, size)
def xp_minimum_filter(arr, footprint=None, size=None):
if _cp is not None and isinstance(arr, _cp.ndarray):
try:
return _cp_ndimage.minimum_filter(arr, footprint=footprint, size=size)
except Exception:
arr = to_cpu(arr)
return ndimage.minimum_filter(arr, footprint=footprint, size=size)
def xp_maximum_filter(arr, footprint=None, size=None):
if _cp is not None and isinstance(arr, _cp.ndarray):
try:
return _cp_ndimage.maximum_filter(arr, footprint=footprint, size=size)
except Exception:
arr = to_cpu(arr)
return ndimage.maximum_filter(arr, footprint=footprint, size=size)
# ---------------------------------------------------------------------------
# Misc
# ---------------------------------------------------------------------------
def gpu_cleanup():
"""Free GPU memory. Call between visualizations to prevent OOM."""
if _cp is not None:
try:
_cp.get_default_memory_pool().free_all_blocks()
except Exception:
pass
def disable_gpu():
"""Disable GPU acceleration for the rest of this process."""
global HAS_GPU, _xp, _cp, _cp_ndimage
if not HAS_GPU:
return
logger.warning("GPU désactivé — passage en mode CPU pour la suite du processus")
HAS_GPU = False
_xp = np
_cp = None
_cp_ndimage = None
def is_gpu_active():
"""Check if GPU acceleration is currently active."""
return HAS_GPU
def safe_gpu_call(func, *args, **kwargs):
"""Call a function with GPU arrays, retrying on CPU if GPU fails."""
try:
return func(*args, **kwargs)
except Exception as e:
err_msg = str(e)
if _cp is not None and ('CUDA' in err_msg or 'cuda' in err_msg or 'GPU' in err_msg or 'Out of memory' in err_msg):
logger.warning(f"Erreur GPU ({e.__class__.__name__}), retry en CPU...")
disable_gpu()
return func(*args, **kwargs)
raise