lightning/tests/accelerators/test_tpu.py

332 lines
11 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 collections
from copy import deepcopy
from unittest.mock import patch
import pytest
import torch
from torch import nn
from torch.utils.data import DataLoader
from pytorch_lightning import Trainer
from pytorch_lightning.accelerators.cpu import CPUAccelerator
from pytorch_lightning.accelerators.tpu import TPUAccelerator
from pytorch_lightning.plugins import PrecisionPlugin, TPUPrecisionPlugin, XLACheckpointIO
from pytorch_lightning.strategies import DDPStrategy, TPUSpawnStrategy
from pytorch_lightning.utilities import find_shared_parameters
from pytorch_lightning.utilities.exceptions import MisconfigurationException
from tests.helpers.boring_model import BoringModel, RandomDataset
from tests.helpers.runif import RunIf
from tests.helpers.utils import pl_multi_process_test
class WeightSharingModule(BoringModel):
def __init__(self):
super().__init__()
self.layer_1 = nn.Linear(32, 10, bias=False)
self.layer_2 = nn.Linear(10, 32, bias=False)
self.layer_3 = nn.Linear(32, 10, bias=False)
self.layer_3.weight = self.layer_1.weight
def forward(self, x):
x = self.layer_1(x)
x = self.layer_2(x)
x = self.layer_3(x)
return x
@RunIf(tpu=True)
@pl_multi_process_test
def test_resume_training_on_cpu(tmpdir):
"""Checks if training can be resumed from a saved checkpoint on CPU."""
# Train a model on TPU
model = BoringModel()
trainer = Trainer(max_epochs=1, accelerator="tpu", devices=8)
trainer.fit(model)
model_path = trainer.checkpoint_callback.best_model_path
# Verify saved Tensors are on CPU
ckpt = torch.load(model_path)
weight_tensor = list(ckpt["state_dict"].values())[0]
assert weight_tensor.device == torch.device("cpu")
# Verify that training is resumed on CPU
trainer = Trainer(max_epochs=1, default_root_dir=tmpdir)
trainer.fit(model, ckpt_path=model_path)
assert trainer.state.finished, f"Training failed with {trainer.state}"
@RunIf(tpu=True)
@pl_multi_process_test
def test_if_test_works_after_train(tmpdir):
"""Ensure that .test() works after .fit()"""
# Train a model on TPU
model = BoringModel()
trainer = Trainer(max_epochs=1, accelerator="tpu", devices=8, default_root_dir=tmpdir, fast_dev_run=True)
trainer.fit(model)
assert len(trainer.test(model)) == 1
@RunIf(tpu=True)
def test_accelerator_cpu_with_tpu_cores_flag():
assert TPUAccelerator.is_available()
trainer = Trainer(accelerator="cpu", devices=8)
assert isinstance(trainer.accelerator, CPUAccelerator)
trainer = Trainer(accelerator="tpu", devices=8)
assert isinstance(trainer.accelerator, TPUAccelerator)
assert isinstance(trainer.strategy, TPUSpawnStrategy)
@RunIf(tpu=True)
@pytest.mark.parametrize(["accelerator", "devices"], [("auto", 8), ("auto", "auto"), ("tpu", None)])
def test_accelerator_tpu(accelerator, devices):
assert TPUAccelerator.is_available()
trainer = Trainer(accelerator=accelerator, devices=devices)
assert isinstance(trainer.accelerator, TPUAccelerator)
assert isinstance(trainer.strategy, TPUSpawnStrategy)
assert trainer.num_devices == 8
@RunIf(tpu=True)
def test_accelerator_tpu_with_tpu_cores_priority():
"""Test for checking `tpu_cores` flag takes priority over `devices`."""
tpu_cores = 8
with pytest.warns(UserWarning, match="The flag `devices=1` will be ignored,"):
trainer = Trainer(accelerator="tpu", devices=1, tpu_cores=tpu_cores)
assert isinstance(trainer.accelerator, TPUAccelerator)
assert trainer.num_devices == tpu_cores
@RunIf(tpu=True)
def test_set_devices_if_none_tpu():
trainer = Trainer(accelerator="tpu", tpu_cores=8)
assert isinstance(trainer.accelerator, TPUAccelerator)
assert trainer.num_devices == 8
@RunIf(tpu=True)
def test_manual_optimization_tpus(tmpdir):
class ManualOptimizationModel(BoringModel):
count = 0
called = collections.defaultdict(int)
def __init__(self):
super().__init__()
self.automatic_optimization = False
@property
def should_update(self):
return self.count % 2 == 0
def on_train_batch_start(self, batch, batch_idx):
self.called["on_train_batch_start"] += 1
self.weight_before = self.layer.weight.clone()
def training_step(self, batch, batch_idx):
self.called["training_step"] += 1
opt = self.optimizers()
output = self.layer(batch)
loss = self.loss(batch, output)
if self.should_update:
self.manual_backward(loss)
opt.step()
opt.zero_grad()
return loss
def on_train_batch_end(self, outputs, batch, batch_idx):
self.called["on_train_batch_end"] += 1
after_before = self.layer.weight.clone()
if self.should_update:
assert not torch.equal(self.weight_before, after_before), self.count
else:
assert torch.equal(self.weight_before, after_before)
assert torch.all(self.layer.weight.grad == 0)
self.count += 1
def on_train_start(self):
opt = self.optimizers()
self.opt_step_patch = patch.object(opt, "step", wraps=opt.step)
self.opt_step_mock = self.opt_step_patch.start()
def on_train_end(self):
assert self.called["training_step"] == 5
assert self.called["on_train_batch_start"] == 5
assert self.called["on_train_batch_end"] == 5
self.opt_step_patch.stop()
assert self.opt_step_mock.call_count == 3
model = ManualOptimizationModel()
model_copy = deepcopy(model)
model.training_step_end = None
model.training_epoch_end = None
trainer = Trainer(
max_epochs=1,
default_root_dir=tmpdir,
limit_train_batches=5,
limit_test_batches=0,
limit_val_batches=0,
accelerator="tpu",
devices=8,
)
trainer.fit(model)
for param, param_copy in zip(model.parameters(), model_copy.parameters()):
assert not torch.equal(param.cpu().data, param_copy.data)
@RunIf(tpu=True)
def test_ddp_cpu_not_supported_on_tpus():
with pytest.raises(MisconfigurationException, match="`accelerator='ddp_cpu'` is not supported on TPU machines"):
Trainer(accelerator="ddp_cpu")
@RunIf(tpu=True)
def test_strategy_choice_tpu_str_ddp_spawn(tmpdir):
with pytest.raises(ValueError, match="TPUAccelerator` can only be used with a `SingleTPUStrategy`"):
Trainer(strategy="ddp_spawn", accelerator="tpu", devices=8)
@RunIf(tpu=True)
def test_strategy_choice_tpu_str_tpu_spawn_debug(tmpdir):
trainer = Trainer(strategy="tpu_spawn_debug", accelerator="tpu", devices=8)
assert isinstance(trainer.strategy, TPUSpawnStrategy)
@RunIf(tpu=True)
def test_strategy_choice_tpu_strategy(tmpdir):
trainer = Trainer(strategy=TPUSpawnStrategy(), accelerator="tpu", devices=8)
assert isinstance(trainer.strategy, TPUSpawnStrategy)
@RunIf(tpu=True)
def test_auto_parameters_tying_tpus(tmpdir):
model = WeightSharingModule()
shared_params = find_shared_parameters(model)
assert shared_params[0] == ["layer_1.weight", "layer_3.weight"]
trainer = Trainer(default_root_dir=tmpdir, limit_train_batches=5, accelerator="tpu", devices=8, max_epochs=1)
trainer.fit(model)
assert torch.all(torch.eq(model.layer_1.weight, model.layer_3.weight))
@RunIf(tpu=True)
def test_auto_parameters_tying_tpus_nested_module(tmpdir):
class SubModule(nn.Module):
def __init__(self, layer):
super().__init__()
self.layer = layer
def forward(self, x):
return self.layer(x)
class NestedModule(BoringModel):
def __init__(self):
super().__init__()
self.layer = nn.Linear(32, 10, bias=False)
self.net_a = SubModule(self.layer)
self.layer_2 = nn.Linear(10, 32, bias=False)
self.net_b = SubModule(self.layer)
def forward(self, x):
x = self.net_a(x)
x = self.layer_2(x)
x = self.net_b(x)
return x
model = NestedModule()
trainer = Trainer(default_root_dir=tmpdir, limit_train_batches=5, accelerator="tpu", devices=8, max_epochs=1)
trainer.fit(model)
assert torch.all(torch.eq(model.net_a.layer.weight, model.net_b.layer.weight))
@RunIf(tpu=True)
def test_tpu_invalid_raises():
strategy = TPUSpawnStrategy(accelerator=TPUAccelerator(), precision_plugin=PrecisionPlugin())
with pytest.raises(ValueError, match="TPUAccelerator` can only be used with a `TPUPrecisionPlugin"):
Trainer(strategy=strategy, devices=8)
strategy = DDPStrategy(accelerator=TPUAccelerator(), precision_plugin=TPUPrecisionPlugin())
with pytest.raises(ValueError, match="TPUAccelerator` can only be used with a `SingleTPUStrategy`"):
Trainer(strategy=strategy, devices=8)
@RunIf(tpu=True)
def test_tpu_invalid_raises_set_precision_with_strategy():
accelerator = TPUAccelerator()
strategy = TPUSpawnStrategy(accelerator=accelerator, precision_plugin=PrecisionPlugin())
with pytest.raises(ValueError, match="`TPUAccelerator` can only be used with a `TPUPrecisionPlugin`"):
Trainer(strategy=strategy, devices=8)
accelerator = TPUAccelerator()
strategy = DDPStrategy(accelerator=accelerator, precision_plugin=TPUPrecisionPlugin())
with pytest.raises(
ValueError, match="The `TPUAccelerator` can only be used with a `SingleTPUStrategy` or `TPUSpawnStrategy"
):
Trainer(strategy=strategy, devices=8)
@RunIf(tpu=True)
def test_xla_checkpoint_plugin_being_default():
trainer = Trainer(accelerator="tpu", devices=8)
assert isinstance(trainer.strategy.checkpoint_io, XLACheckpointIO)
@RunIf(tpu=True)
@patch("pytorch_lightning.strategies.tpu_spawn.xm")
def test_mp_device_dataloader_attribute(_):
dataset = RandomDataset(32, 64)
dataloader = TPUSpawnStrategy().process_dataloader(DataLoader(dataset))
assert dataloader.dataset == dataset
@RunIf(tpu=True)
def test_warning_if_tpus_not_used():
with pytest.warns(UserWarning, match="TPU available but not used. Set `accelerator` and `devices`"):
Trainer()
@RunIf(tpu=True)
@pl_multi_process_test
@pytest.mark.parametrize(
["devices", "expected_device_ids"],
[
(1, [0]),
(8, list(range(8))),
("8", list(range(8))),
([2], [2]),
("2,", [2]),
],
)
def test_trainer_config_device_ids(devices, expected_device_ids):
trainer = Trainer(accelerator="tpu", devices=devices)
assert trainer.device_ids == expected_device_ids
assert trainer.num_devices == len(expected_device_ids)