lightning/pytorch_lightning/tuner/auto_gpu_select.py

57 lines
1.7 KiB
Python

# Copyright The PyTorch Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import torch
from pytorch_lightning.utilities.exceptions import MisconfigurationException
def pick_multiple_gpus(nb):
'''
Raises:
MisconfigurationException:
If ``gpus`` is set to 0, when ``auto_select_gpus=True``.
'''
if nb == 0:
raise MisconfigurationException(
r"auto_select_gpus=True, gpus=0 is not a valid configuration.\
Please select a valid number of GPU resources when using auto_select_gpus."
)
nb = torch.cuda.device_count() if nb == -1 else nb
picked = []
for _ in range(nb):
picked.append(pick_single_gpu(exclude_gpus=picked))
return picked
def pick_single_gpu(exclude_gpus: list):
'''
Raises:
RuntimeError:
If you try to allocate a GPU, when no GPUs are available.
'''
for i in range(torch.cuda.device_count()):
if i in exclude_gpus:
continue
# Try to allocate on device:
device = torch.device(f"cuda:{i}")
try:
torch.ones(1).to(device)
except RuntimeError:
continue
return i
raise RuntimeError("No GPUs available.")