lightning/tests/plugins/test_ddp_spawn_plugin.py

173 lines
6.5 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.
from pathlib import Path
from unittest.mock import Mock
import pytest
import torch
from torch.nn.parallel.distributed import DistributedDataParallel
from pytorch_lightning import LightningModule, Trainer
from pytorch_lightning.plugins import DDPSpawnPlugin
from pytorch_lightning.trainer.states import TrainerFn
from tests.helpers.boring_model import BoringDataModule, BoringModel
from tests.helpers.runif import RunIf
class BoringModelDDPCPU(BoringModel):
def on_train_start(self) -> None:
# make sure that the model is on CPU when training
assert self.device == torch.device("cpu")
class BoringCallbackDDPSpawnModel(BoringModel):
def __init__(self, name: str, val: float):
super().__init__()
self.name = name
self.val = val
def validation_step(self, batch, batch_idx):
self.log(self.name, self.val)
return super().validation_step(batch, batch_idx)
def add_to_queue(self, queue) -> None:
queue.put("test_val")
return super().add_to_queue(queue)
def get_from_queue(self, queue) -> None:
self.test_val = queue.get()
return super().get_from_queue(queue)
@RunIf(skip_windows=True, skip_49370=True)
def test_ddp_cpu():
"""Tests if device is set correctly when training for DDPSpawnPlugin."""
trainer = Trainer(num_processes=2, fast_dev_run=True)
# assert training type plugin attributes for device setting
assert isinstance(trainer.training_type_plugin, DDPSpawnPlugin)
assert not trainer.training_type_plugin.on_gpu
assert not trainer.training_type_plugin.on_tpu
assert trainer.training_type_plugin.root_device == torch.device("cpu")
model = BoringModelDDPCPU()
trainer.fit(model)
@RunIf(min_gpus=2)
def test_ddp_spawn_extra_parameters(tmpdir):
"""Tests if device is set correctly when training for DDPSpawnPlugin and tests add_to_queue/get_from_queue with
Lightning Module (deprecated way)."""
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True, gpus=2, strategy="ddp_spawn")
assert isinstance(trainer.training_type_plugin, DDPSpawnPlugin)
assert trainer.training_type_plugin.on_gpu
assert trainer.training_type_plugin.root_device == torch.device("cuda:0")
val: float = 1.0
val_name: str = "val_acc"
model = BoringCallbackDDPSpawnModel(val_name, val)
dm = BoringDataModule()
trainer.fit(model, datamodule=dm)
assert trainer.callback_metrics[val_name] == torch.tensor(val)
assert model.test_val == "test_val"
class TestDDPSpawnPlugin(DDPSpawnPlugin):
def add_to_queue(self, trainer, queue) -> None:
queue.put("new_test_val")
return super().add_to_queue(trainer, queue)
def get_from_queue(self, trainer: Trainer, queue) -> None:
self.new_test_val = queue.get()
return super().get_from_queue(trainer, queue)
@RunIf(skip_windows=True, skip_49370=True)
def test_ddp_spawn_add_get_queue(tmpdir):
"""Tests add_to_queue/get_from_queue with DDPSpawnPlugin."""
ddp_spawn_plugin = TestDDPSpawnPlugin()
trainer = Trainer(default_root_dir=tmpdir, fast_dev_run=True, num_processes=2, strategy=ddp_spawn_plugin)
val: float = 1.0
val_name: str = "val_acc"
model = BoringCallbackDDPSpawnModel(val_name, val)
dm = BoringDataModule()
trainer.fit(model, datamodule=dm)
assert trainer.callback_metrics[val_name] == torch.tensor(val)
assert ddp_spawn_plugin.new_test_val == "new_test_val"
class BoringModelDDP(BoringModel):
def on_train_start(self) -> None:
"""Check if trainer module is wrapped as DistributedDataParallel during training stage."""
assert isinstance(self.trainer.model, DistributedDataParallel)
def on_validation_start(self) -> None:
"""Check if trainer module remains as LightningModule during test stage."""
if self.trainer.state.fn == TrainerFn.FITTING:
assert isinstance(self.trainer.model, DistributedDataParallel)
else:
assert isinstance(self.trainer.model, LightningModule)
def on_test_start(self) -> None:
"""Check if trainer module remains as LightningModule during test stage."""
assert isinstance(self.trainer.model, LightningModule)
def on_predict_start(self) -> None:
"""Check if trainer module remains as LightningModule during prediction stage."""
assert isinstance(self.trainer.model, LightningModule)
@RunIf(skip_windows=True, skip_49370=True, skip_hanging_spawn=True)
def test_ddp_spawn_configure_ddp(tmpdir):
"""Tests with ddp spawn plugin."""
trainer = Trainer(default_root_dir=tmpdir, num_processes=2, strategy="ddp_spawn", fast_dev_run=True)
model = BoringModelDDP()
trainer.fit(model)
trainer.validate(model, dataloaders=model.val_dataloader())
trainer.test(model, dataloaders=model.test_dataloader())
trainer.predict(model, dataloaders=model.predict_dataloader())
@pytest.mark.parametrize("trainer_fn", [TrainerFn.FITTING, "other"])
def test_ddp_spawn_transfer_weights(tmpdir, trainer_fn):
"""Tests that the spawn plugin transfers the new weights to the main process and deletes the temporary file."""
model = Mock(wraps=BoringModel(), spec=BoringModel)
plugin = DDPSpawnPlugin()
plugin.model = model
trainer = Trainer(default_root_dir=tmpdir)
trainer.state.fn = trainer_fn # pretend we are in a particular trainer state
temp_file = Path(tmpdir, ".temp.ckpt")
assert not temp_file.exists()
spawn_output = plugin._collect_rank_zero_results(trainer, {})
model.state_dict.assert_called_once()
if trainer_fn == TrainerFn.FITTING:
assert spawn_output.weights_path == str(temp_file)
assert temp_file.exists()
else:
assert spawn_output.weights_path is None
assert not temp_file.exists()
# <-- here would normally be the multiprocessing boundary
plugin._recover_results_in_main_process(spawn_output, trainer)
assert model.load_state_dict.call_count == int(spawn_output.weights_path is not None)
assert not temp_file.exists()