Source code for lightning.fabric.accelerators.mps
# Copyright The Lightning AI 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,
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# See the License for the specific language governing permissions and
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import os
import platform
from functools import lru_cache
from typing import List, Optional, Union
import torch
from typing_extensions import override
from lightning.fabric.accelerators.accelerator import Accelerator
from lightning.fabric.accelerators.registry import _AcceleratorRegistry
[docs]class MPSAccelerator(Accelerator):
"""Accelerator for Metal Apple Silicon GPU devices.
.. warning:: Use of this accelerator beyond import and instantiation is experimental.
"""
[docs] @override
def setup_device(self, device: torch.device) -> None:
"""
Raises:
ValueError:
If the selected device is not MPS.
"""
if device.type != "mps":
raise ValueError(f"Device should be MPS, got {device} instead.")
[docs] @override
def teardown(self) -> None:
pass
[docs] @staticmethod
@override
def parse_devices(devices: Union[int, str, List[int]]) -> Optional[List[int]]:
"""Accelerator device parsing logic."""
from lightning.fabric.utilities.device_parser import _parse_gpu_ids
return _parse_gpu_ids(devices, include_mps=True)
[docs] @staticmethod
@override
def get_parallel_devices(devices: Union[int, str, List[int]]) -> List[torch.device]:
"""Gets parallel devices for the Accelerator."""
parsed_devices = MPSAccelerator.parse_devices(devices)
assert parsed_devices is not None
return [torch.device("mps", i) for i in range(len(parsed_devices))]
[docs] @staticmethod
@override
def auto_device_count() -> int:
"""Get the devices when set to auto."""
return 1
[docs] @staticmethod
@override
@lru_cache(1)
def is_available() -> bool:
"""MPS is only available on a machine with the ARM-based Apple Silicon processors."""
mps_disabled = os.getenv("DISABLE_MPS", "0") == "1"
return not mps_disabled and torch.backends.mps.is_available() and platform.processor() in ("arm", "arm64")
@classmethod
@override
def register_accelerators(cls, accelerator_registry: _AcceleratorRegistry) -> None:
accelerator_registry.register(
"mps",
cls,
description=cls.__name__,
)
def _get_all_available_mps_gpus() -> List[int]:
"""
Returns:
A list of all available MPS GPUs
"""
return [0] if MPSAccelerator.is_available() else []