# 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, # 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 os import platform from functools import lru_cache from typing import Optional, Union import torch from typing_extensions import override from lightning_fabric.accelerators.accelerator import Accelerator from lightning_fabric.accelerators.registry import _AcceleratorRegistry class MPSAccelerator(Accelerator): """Accelerator for Metal Apple Silicon GPU devices. .. warning:: Use of this accelerator beyond import and instantiation is experimental. """ @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.") @override def teardown(self) -> None: pass @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) @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))] @staticmethod @override def auto_device_count() -> int: """Get the devices when set to auto.""" return 1 @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 []