632 lines
24 KiB
Python
632 lines
24 KiB
Python
# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from __future__ import annotations
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import multiprocessing
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import os
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import signal
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import sys
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import warnings
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from typing import TYPE_CHECKING, Any, Literal, TypedDict
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# deprecated module import
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# (TODO: GhostScreaming) It will be removed later.
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from paddle.base import core
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from paddle.device import get_device
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from paddle.distributed.cloud_utils import (
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_get_trainers_num,
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get_cluster_and_pod,
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)
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from paddle.distributed.fleet.cloud_utils import use_paddlecloud
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from paddle.distributed.fleet.launch import get_cluster_from_args
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from paddle.distributed.fleet.launch_utils import (
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DeviceMode,
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block_windows_and_macos,
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check_backend,
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)
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from paddle.distributed.utils.launch_utils import (
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_prepare_trainer_env,
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_print_arguments,
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get_host_name_ip,
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)
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from paddle.framework import set_flags
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if TYPE_CHECKING:
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from collections.abc import Callable, Iterable
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from typing_extensions import NotRequired, Unpack
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class _SpawnOptions(TypedDict):
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start_method: NotRequired[Literal['spawn', 'fork', 'forkserver']]
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gpus: NotRequired[str | None]
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xpus: NotRequired[str | None]
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ips: NotRequired[str]
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__all__ = []
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class ParallelEnvArgs:
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def __init__(self):
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# Paddle cluster nodes ips, such as 192.168.0.16,192.168.0.17..
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self.cluster_node_ips = None
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# The current node ip.
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self.node_ip = None
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# whether to use paddlecloud platform to run your multi-process job.
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# If false, no need to set this argument.
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self.use_paddlecloud = None
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# The trainer's started port on a single node
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self.started_port = None
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# Print the config or not
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self.print_config = True
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# It's for gpu training and the training process will run
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# on the selected_devices, each process is bound to a single GPU.
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# And if it's not set, this module will use all the gpu cards
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# for training.
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self.selected_devices = None
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def _options_valid_check(options):
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# `print_config` kept as a debug options, not show to users
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supported_options = [
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'start_method',
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'ips',
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'gpus',
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'xpus',
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'print_config',
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'backend',
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]
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deprecated_options = [
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'selected_devices',
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'started_port',
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'cluster_node_ips',
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'node_ip',
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'use_paddlecloud',
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]
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for key in options:
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if key not in supported_options:
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if key in deprecated_options:
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warnings.warn(
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f"The config option ({key}) of `paddle.distributed.spawn` is deprecated. "
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"Please use the latest config options stated in the `spawn` API documentation.",
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DeprecationWarning,
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)
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else:
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raise ValueError(
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f"The config option ({key}) of `paddle.distributed.spawn` is not supported."
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)
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def _get_default_nprocs():
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device = get_device()
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if device in core.get_available_custom_device():
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return core.get_custom_device_count(device.split(":")[0])
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elif 'gpu' in device:
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return core.get_cuda_device_count()
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elif 'xpu' in device:
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return core.get_xpu_device_count()
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elif 'cpu' in device:
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return multiprocessing.cpu_count()
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else:
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raise RuntimeError(
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f"`paddle.distributed.spawn` does not support parallel training on device `{device}` now."
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)
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def _get_default_backend():
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device = get_device()
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if device in core.get_available_custom_device():
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return 'xccl'
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elif 'gpu' in device:
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return 'nccl'
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elif 'xpu' in device:
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return 'bkcl'
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elif 'cpu' in device:
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return 'gloo'
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else:
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raise RuntimeError(
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f"`paddle.distributed.spawn` does not support parallel training on device `{device}` now."
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)
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def _get_node_ip(ips):
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node_ip = None
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node_ips = [x.strip() for x in ips.split(',')]
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if len(node_ips) == 1:
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node_ip = node_ips[0]
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else:
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_, node_ip = get_host_name_ip()
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return node_ip
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def _get_subprocess_env_list(nprocs, options):
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# NOTE (xiongkun03) Why put backend deduction here ?
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# Because _get_subprocess_env_list is used by many testcases.
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# So for compatibility, we put backend deduction here
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# logic for handle backend option
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if 'backend' not in options or options['backend'] == 'auto':
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options['backend'] = _get_default_backend()
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check_backend(options['backend'])
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block_windows_and_macos(options['backend'])
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# construct processes env list
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processes_env_list = []
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# get args from kwargs
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args = ParallelEnvArgs()
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# deal with `ips`
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args.cluster_node_ips = options.get('ips', None)
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if args.cluster_node_ips is None:
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args.cluster_node_ips = options.get('cluster_node_ips', None)
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if args.cluster_node_ips is None:
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args.cluster_node_ips = "127.0.0.1"
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# deal with `gpus` or `xpus`
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# set default selected devices(gpus or xpus)
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# e.g. if the nprocs is 4, the selected gpus is "0,1,2,3"
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# NOTE(chenweihang): [ why not use FLAGS_selected_gpus or FLAGS_selected_xpus directly? ]
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# because the FLAGS_selected_gpus or FLAGS_selected_xpus may be used in other place,
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# if we set FLAGS_selected_gpus or FLAGS_selected_xpus to be `0,1,2,3`, it may cause error
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# when using `ParallelEnv`
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# NOTE(chenweihang): use absolute gpu or xpu card id
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if options['backend'] == 'nccl':
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args.selected_devices = options.get('gpus', None)
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if args.selected_devices is None:
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args.selected_devices = options.get('selected_devices', None)
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env_devices = os.getenv("CUDA_VISIBLE_DEVICES", None)
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if env_devices is None or env_devices == "":
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env_devices_list = [
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str(x) for x in range(core.get_cuda_device_count())
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]
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else:
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env_devices_list = env_devices.split(',')
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if args.selected_devices is None:
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if len(env_devices_list) < nprocs:
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raise RuntimeError(
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f"the number of visible devices({len(env_devices_list)}) is less than the number "
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f"of spawn processes({nprocs}), please ensure that the correct "
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"`nprocs` argument is passed or the environment variable "
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"`CUDA_VISIBLE_DEVICES` is correctly configured."
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)
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args.selected_devices = ",".join(
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[str(env_devices_list[x]) for x in range(0, nprocs)]
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)
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else:
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selected_device_list = args.selected_devices.split(',')
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if len(selected_device_list) != nprocs:
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raise ValueError(
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f"The number of selected devices({len(selected_device_list)}) is not equal to "
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f"the number of spawn processes({nprocs}), please ensure that the "
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"correct `nprocs` and `gpus` arguments are passed."
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)
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for card_id in selected_device_list:
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if card_id not in env_devices_list:
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raise ValueError(
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"The selected gpu card {} cannot found in "
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"CUDA_VISIBLE_DEVICES ({}).".format(
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card_id, ",".join(env_devices_list)
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)
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)
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elif options['backend'] == 'bkcl':
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args.selected_devices = options.get('xpus', None)
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if args.selected_devices is None:
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args.selected_devices = options.get('selected_devices', None)
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env_devices = os.getenv("XPU_VISIBLE_DEVICES", None)
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if env_devices is None or env_devices == "":
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env_devices_list = [
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str(x) for x in range(core.get_xpu_device_count())
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]
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else:
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env_devices_list = env_devices.split(',')
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if args.selected_devices is None:
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if len(env_devices_list) < nprocs:
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raise RuntimeError(
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f"the number of visible devices({len(env_devices_list)}) is less than the number "
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f"of spawn processes({nprocs}), please ensure that the correct "
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"`nprocs` argument is passed or the environment variable "
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"`XPU_VISIBLE_DEVICES` is correctly configured."
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)
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args.selected_devices = ",".join(
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[str(env_devices_list[x]) for x in range(0, nprocs)]
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)
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else:
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selected_device_list = args.selected_devices.split(',')
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if len(selected_device_list) != nprocs:
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raise ValueError(
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f"The number of selected devices({len(selected_device_list)}) is not equal to "
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f"the number of spawn processes({nprocs}), please ensure that the "
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"correct `nprocs` and `xpus` arguments are passed."
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)
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for card_id in selected_device_list:
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if card_id not in env_devices_list:
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raise ValueError(
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"The selected xpu card {} cannot found in "
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"XPU_VISIBLE_DEVICES ({}).".format(
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card_id, ",".join(env_devices_list)
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)
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)
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elif options['backend'] == 'gloo':
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# TODO check gpu / xpu flag must not exist
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warnings.warn(
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"Your model will be trained under CPUONLY mode by using GLOO,"
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"because CPUPlace is specified manually or your installed PaddlePaddle only support CPU Device."
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)
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args.paddle_cpuonly = True
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args.selected_devices = None
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args.ips = args.cluster_node_ips
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assert options.get('use_paddlecloud', None) is None, (
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"CPUONLY spawn doesn't support use paddle cloud"
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)
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assert len(args.cluster_node_ips.split(',')) <= 1, (
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"CPUONLY spawn only support single trainer, that is len(ips)=1, but got %s."
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)
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assert _get_trainers_num() == 1, (
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"CPUONLY spawn doesn't support multi-trainer"
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)
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elif options['backend'] == 'xccl':
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args.selected_devices = None
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custom_device_name = core.get_all_custom_device_type()[0]
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env_devices = os.getenv(f"FLAGS_selected_{custom_device_name}s", None)
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if env_devices is None or env_devices == "":
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env_devices_list = [
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str(x)
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for x in range(core.get_custom_device_count(custom_device_name))
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]
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else:
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env_devices_list = env_devices.split(',')
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if len(env_devices_list) < nprocs:
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raise RuntimeError(
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f"the number of visible devices({len(env_devices_list)}) is less than the number "
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f"of spawn processes({nprocs}), please ensure that the correct "
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"`nprocs` argument is passed or the environment variable "
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f"`FLAGS_selected_{custom_device_name}s` is correctly configured."
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)
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args.selected_devices = ",".join(
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[str(env_devices_list[x]) for x in range(0, nprocs)]
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)
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# set other inner args
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args.node_ip = options.get('node_ip', None)
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if args.node_ip is None:
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args.node_ip = _get_node_ip(args.cluster_node_ips)
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args.started_port = options.get('started_port', None)
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args.use_paddlecloud = options.get('use_paddlecloud', None)
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if args.use_paddlecloud is None:
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args.use_paddlecloud = use_paddlecloud()
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# get cluster and pod config
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if options['backend'] == 'gloo':
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devices_per_proc = list(range(0, nprocs))
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cluster, pod = get_cluster_from_args(
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args, DeviceMode.CPU, devices_per_proc
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)
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else:
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cluster, pod = get_cluster_and_pod(args)
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# prepare subprocess env list
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for trainer in pod.trainers:
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processes_env_list.append(
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_prepare_trainer_env(cluster, trainer, options['backend'])
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)
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# [Debug] print config
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args.print_config = options.get('print_config', False)
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if args.print_config:
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_print_arguments(args)
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return processes_env_list
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def _remove_risky_env():
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# remove useless env vars
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# no copy, each process will hold env vars itself
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os.environ.pop("http_proxy", None)
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os.environ.pop("https_proxy", None)
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def _set_trainer_env(env_dict, backend):
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# NOTE(chenweihang): [ Why need set FLAGS_selected_gpus or FLAGS_selected_xpus here? ]
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# When the child process starts, it will inherit the configuration of the
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# main process and set the FLAGS once, but the environment variable has
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# not been set at this time, which leads to the FLAGS_selected_gpus or FLAGS_selected_xpus
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# is keep same with mainprocess(usually empty), so manually update the flags here
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# NOTE(xiongkun): why put backend here? because if gloo, we shouldn't set FLAGS_selectedXXX
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#
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if backend == 'nccl':
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set_flags({'FLAGS_selected_gpus': env_dict['FLAGS_selected_gpus']})
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elif backend == 'bkcl':
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set_flags({'FLAGS_selected_xpus': env_dict['FLAGS_selected_xpus']})
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else:
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# NOTE(xiongkun) why not raise Error ?
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# So far, we added support for CPU parallel, and will be applied when paddle is not
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# compiled with cuda or xp. just do nothing.
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pass
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for var_name in env_dict:
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os.environ[var_name] = env_dict[var_name]
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def _func_wrapper(func, args, error_queue, return_queue, env_dict, backend):
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try:
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# config subprocess environment variables
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_remove_risky_env()
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_set_trainer_env(env_dict, backend)
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# execute function
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result = func(*args)
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# record function return value
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return_queue.put(result)
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except KeyboardInterrupt:
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pass
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except Exception:
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import traceback
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error_queue.put(traceback.format_exc())
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sys.exit(1)
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class MultiprocessContext:
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def __init__(self, processes, error_queues, return_queues):
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self.error_queues = error_queues
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# NOTE(chenweihang): The `spawn` method is mainly used
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# to wrap the outermost execution function of the program for
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# parallel execution. Generally, the return value is not concerned,
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# but if the user needs to obtain the return value, users can get
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# the return result of each process from context.return_queues
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self.return_queues = return_queues
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self.processes = processes
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self.sentinels = {
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process.sentinel: index for index, process in enumerate(processes)
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}
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def join(self, timeout=None):
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if len(self.sentinels) == 0:
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return True
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ready = multiprocessing.connection.wait(
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self.sentinels.keys(), timeout=timeout
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)
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error_index = None
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for sentinel in ready:
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index = self.sentinels.pop(sentinel)
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process = self.processes[index]
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process.join()
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if process.exitcode != 0:
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error_index = index
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break
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if error_index is None:
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return len(self.sentinels) == 0
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for process in self.processes:
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if process.is_alive():
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process.terminate()
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process.join()
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self._throw_exception(error_index)
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def _throw_exception(self, error_index):
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if self.error_queues[error_index].empty():
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exitcode = self.processes[error_index].exitcode
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if exitcode < 0:
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name = signal.Signals(-exitcode).name
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raise Exception(
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f"Process {error_index} terminated with signal {name}."
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)
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else:
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raise Exception(
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f"Process {error_index} terminated with exit code {exitcode}."
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)
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original_trace = self.error_queues[error_index].get()
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msg = (
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"\n\n----------------------------------------------\n"
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f"Process {error_index} terminated with the following error:\n"
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"----------------------------------------------\n\n"
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)
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msg += original_trace
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raise Exception(msg)
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def spawn(
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func: Callable[..., None],
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args: Iterable[Any] = (),
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nprocs: int = -1,
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join: bool = True,
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daemon: bool = False,
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**options: Unpack[_SpawnOptions],
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) -> MultiprocessContext:
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"""
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Start multiple processes with ``spawn`` method for parallel training.
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.. note::
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``spawn`` now only supports GPU or XPU collective mode. The collective mode
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of GPU and XPU cannot be started at the same time, so the option `gpus` and
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`xpus` cannot be configured at the same time.
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Args:
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func (function): The target function is called by spawned process.
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This function need to be able to pickled, so it must be defined
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at the top level of a module.
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args (list|tuple, optional): Arguments passed to ``func``.
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nprocs (int, optional): Number of processed to start. Default: -1.
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when nprocs is -1, the available device will be obtained from
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the environment variable when the model is executed: If use GPU,
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the currently available device ID is obtained from the environment
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variable CUDA_VISIBLE_DEVICES; If use XPU, the currently available
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device ID is obtained from the environment variable XPU_VISIBLE_DEVICES.
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join (bool, optional): Perform a blocking join on all spawned processes.
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Default: True.
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daemon (bool, optional): The spawned processes' daemon flag. Default: False.
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**options(dict, optional): Other initial parallel execution environment
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configuration options. The following options are currently supported:
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(1) start_method (string): the way to start a process.
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The start method can be ``spawn`` , ``fork`` , ``forkserver`` .
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Because the CUDA runtime does not support the ``fork`` start method,
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when use CUDA in subprocesses, we should start process by ``spawn``
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or ``forkserver`` method. Default: "spawn" ;
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(2) gpus (string): The training process will run on the
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selected gpus, such as "0,1,2,3". Default: None;
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(3) xpus (string): The training process will run on the
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selected xpus, such as "0,1,2,3". Default: None;
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(5) ips (string): Paddle cluster nodes ips, such as
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"192.168.0.16,192.168.0.17". Default: "127.0.0.1" .
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Returns:
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``MultiprocessContext`` object, it hold the spawned processes.
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Examples:
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.. code-block:: pycon
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>>> # doctest: +REQUIRES(env:DISTRIBUTED)
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>>> import paddle
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>>> import paddle.nn as nn
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>>> import paddle.optimizer as opt
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>>> import paddle.distributed as dist
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>>> class LinearNet(nn.Layer):
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... def __init__(self):
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... super().__init__()
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... self._linear1 = nn.Linear(10, 10)
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... self._linear2 = nn.Linear(10, 1)
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...
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... def forward(self, x):
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... return self._linear2(self._linear1(x))
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>>> def train(print_result=False):
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... # 1. initialize parallel environment
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... group = dist.init_parallel_env()
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... process_group = group.process_group if group else None
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... # 2. create data parallel layer & optimizer
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... layer = LinearNet()
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... dp_layer = paddle.DataParallel(layer, group=process_group) # type: ignore[arg-type]
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... loss_fn = nn.MSELoss()
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... adam = opt.Adam(learning_rate=0.001, parameters=dp_layer.parameters())
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... # 3. run layer
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... inputs = paddle.randn([10, 10], 'float32')
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... outputs = dp_layer(inputs)
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... labels = paddle.randn([10, 1], 'float32')
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... loss = loss_fn(outputs, labels)
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... if print_result is True:
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... print("loss:", loss.numpy())
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... loss.backward()
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... adam.step()
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... adam.clear_grad()
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>>> # Usage 1: only pass function.
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>>> # If your training method no need any argument, and
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>>> # use all visible devices for parallel training.
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>>> if __name__ == '__main__':
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... dist.spawn(train)
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>>> # Usage 2: pass function and arguments.
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>>> # If your training method need some arguments, and
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>>> # use all visible devices for parallel training.
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>>> if __name__ == '__main__':
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... dist.spawn(train, args=(True,))
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>>> # Usage 3: pass function, arguments and nprocs.
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>>> # If your training method need some arguments, and
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>>> # only use part of visible devices for parallel training.
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>>> # If your machine hold 8 cards {0,1,2,3,4,5,6,7},
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>>> # this case will use cards {0,1}; If you set
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>>> # CUDA_VISIBLE_DEVICES=4,5,6,7, this case will use
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>>> # cards {4,5}
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>>> if __name__ == '__main__':
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... dist.spawn(train, args=(True,), nprocs=2)
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>>> # Usage 4: pass function, arguments, nprocs and gpus.
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>>> # If your training method need some arguments, and
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>>> # only use part of visible devices for parallel training,
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>>> # but you can't set your machine's environment variable
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>>> # CUDA_VISIBLE_DEVICES, such as it is None or all cards
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>>> # {0,1,2,3,4,5,6,7}, you can pass `gpus` to
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>>> # select the GPU cards you want to use. For example,
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>>> # this case will use cards {4,5} if your machine hold 8 cards.
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>>> if __name__ == '__main__':
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... dist.spawn(train, args=(True,), nprocs=2, gpus='4,5')
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"""
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# Give an error hint when the users enter a configuration option
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# that does not exist
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_options_valid_check(options)
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|
|
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# get default nprocs
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if nprocs == -1:
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|
nprocs = _get_default_nprocs()
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|
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# NOTE(chenweihang): [ why need get cluster info before run? ]
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|
# when using `paddle.distributed.spawn` start parallel training,
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|
# we should get cluster info before starting subprocess, and pass
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# correct info to each subprocess
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procs_env_list = _get_subprocess_env_list(nprocs, options)
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|
|
|
# start processes
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|
# NOTE(chenweihang): [ why default start method is spawn? ]
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|
# The CUDA runtime does not support the fork start method,
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|
# either the spawn or forkserver start method are required
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|
# to use CUDA in subprocesses.
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|
start_method = options.get('start_method', None)
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|
if start_method is None:
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|
start_method = 'spawn'
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|
mp = multiprocessing.get_context(start_method)
|
|
|
|
error_queues = []
|
|
return_queues = []
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|
processes = []
|
|
for i in range(nprocs):
|
|
error_queue = mp.SimpleQueue()
|
|
return_queue = mp.SimpleQueue()
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|
process = mp.Process(
|
|
target=_func_wrapper,
|
|
args=(
|
|
func,
|
|
args,
|
|
error_queue,
|
|
return_queue,
|
|
procs_env_list[i],
|
|
options['backend'],
|
|
),
|
|
)
|
|
process.daemon = daemon
|
|
process.start()
|
|
error_queues.append(error_queue)
|
|
return_queues.append(return_queue)
|
|
processes.append(process)
|
|
|
|
context = MultiprocessContext(processes, error_queues, return_queues)
|
|
if not join:
|
|
return context
|
|
|
|
# loop until all process end
|
|
while not context.join():
|
|
pass
|
|
|
|
# finally return context
|
|
return context
|