lightning/pytorch_lightning/utilities/xla_device.py

101 lines
3.2 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 functools
import os
import queue as q
import traceback
from multiprocessing import Process, Queue
from typing import Any, Callable, Union
from pytorch_lightning.utilities.imports import _XLA_AVAILABLE
if _XLA_AVAILABLE:
import torch_xla.core.xla_model as xm
# define TPU availability timeout in seconds
TPU_CHECK_TIMEOUT = 60
def inner_f(queue: Queue, func: Callable, *args: Any, **kwargs: Any) -> None: # pragma: no cover
try:
queue.put(func(*args, **kwargs))
# todo: specify the possible exception
except Exception:
traceback.print_exc()
queue.put(None)
def pl_multi_process(func: Callable) -> Callable:
@functools.wraps(func)
def wrapper(*args: Any, **kwargs: Any) -> Union[bool, Any]:
queue: Queue = Queue()
proc = Process(target=inner_f, args=(queue, func, *args), kwargs=kwargs)
proc.start()
proc.join(TPU_CHECK_TIMEOUT)
try:
return queue.get_nowait()
except q.Empty:
traceback.print_exc()
return False
return wrapper
class XLADeviceUtils:
"""Used to detect the type of XLA device."""
_TPU_AVAILABLE = False
@staticmethod
@pl_multi_process
def _is_device_tpu() -> bool:
"""Check if TPU devices are available.
Return:
A boolean value indicating if TPU devices are available
"""
# For the TPU Pod training process, for example, if we have
# TPU v3-32 with 4 VMs, the world size would be 4 and as
# we would have to use `torch_xla.distributed.xla_dist` for
# multiple VMs and TPU_CONFIG won't be available, running
# `xm.get_xla_supported_devices("TPU")` won't be possible.
return (xm.xrt_world_size() > 1) or bool(xm.get_xla_supported_devices("TPU"))
@staticmethod
def xla_available() -> bool:
"""Check if XLA library is installed.
Return:
A boolean value indicating if a XLA is installed
"""
return _XLA_AVAILABLE
@staticmethod
def tpu_device_exists() -> bool:
"""Runs XLA device check within a separate process.
Return:
A boolean value indicating if a TPU device exists on the system
"""
if os.getenv("PL_TPU_AVAILABLE", "0") == "1":
XLADeviceUtils._TPU_AVAILABLE = True
if XLADeviceUtils.xla_available() and not XLADeviceUtils._TPU_AVAILABLE:
XLADeviceUtils._TPU_AVAILABLE = XLADeviceUtils._is_device_tpu()
if XLADeviceUtils._TPU_AVAILABLE:
os.environ["PL_TPU_AVAILABLE"] = "1"
return XLADeviceUtils._TPU_AVAILABLE