lightning/tests/callbacks/test_finetuning_callback.py

426 lines
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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 collections import OrderedDict
import pytest
import torch
from torch import nn
from torch.optim import Optimizer, SGD
from torch.utils.data import DataLoader
from pytorch_lightning import LightningModule, seed_everything, Trainer
from pytorch_lightning.callbacks import BackboneFinetuning, BaseFinetuning, ModelCheckpoint
from pytorch_lightning.utilities.imports import _TORCH_GREATER_EQUAL_1_11
from tests.helpers import BoringModel, RandomDataset
class TestBackboneFinetuningCallback(BackboneFinetuning):
def on_train_epoch_start(self, trainer, pl_module):
super().on_train_epoch_start(trainer, pl_module)
epoch = trainer.current_epoch
if self.unfreeze_backbone_at_epoch <= epoch:
optimizer = trainer.optimizers[0]
current_lr = optimizer.param_groups[0]["lr"]
backbone_lr = self.previous_backbone_lr
if epoch < 6:
assert backbone_lr <= current_lr
else:
assert backbone_lr == current_lr
def test_finetuning_callback(tmpdir):
"""Test finetuning callbacks works as expected."""
seed_everything(42)
class FinetuningBoringModel(BoringModel):
def __init__(self):
super().__init__()
self.backbone = nn.Sequential(nn.Linear(32, 32, bias=False), nn.BatchNorm1d(32), nn.ReLU())
self.layer = torch.nn.Linear(32, 2)
self.backbone.has_been_used = False
def training_step(self, batch, batch_idx):
output = self(batch)
loss = self.loss(batch, output)
return {"loss": loss}
def forward(self, x):
self.backbone.has_been_used = True
x = self.backbone(x)
return self.layer(x)
def configure_optimizers(self):
optimizer = torch.optim.SGD(self.layer.parameters(), lr=0.1)
lr_scheduler = torch.optim.lr_scheduler.StepLR(optimizer, step_size=1, gamma=0.7)
return [optimizer], [lr_scheduler]
def train_dataloader(self):
return DataLoader(RandomDataset(32, 64), batch_size=2)
model = FinetuningBoringModel()
callback = TestBackboneFinetuningCallback(unfreeze_backbone_at_epoch=3, verbose=False)
trainer = Trainer(limit_train_batches=4, default_root_dir=tmpdir, callbacks=[callback], max_epochs=8)
trainer.fit(model)
assert model.backbone.has_been_used
class TestBackboneFinetuningWarningCallback(BackboneFinetuning):
def finetune_function(self, pl_module, epoch: int, optimizer, opt_idx: int):
"""Called when the epoch begins."""
if epoch == 0:
self.unfreeze_and_add_param_group(
pl_module.backbone, optimizer, 0.1, train_bn=self.train_bn, initial_denom_lr=self.initial_denom_lr
)
def test_finetuning_callback_warning(tmpdir):
"""Test finetuning callbacks works as expected."""
seed_everything(42)
class FinetuningBoringModel(BoringModel):
def __init__(self):
super().__init__()
self.backbone = nn.Linear(32, 2, bias=False)
self.layer = None
self.backbone.has_been_used = False
def training_step(self, batch, batch_idx):
output = self(batch)
loss = self.loss(batch, output)
return {"loss": loss}
def forward(self, x):
self.backbone.has_been_used = True
x = self.backbone(x)
return x
def train_dataloader(self):
return DataLoader(RandomDataset(32, 64), batch_size=2)
def configure_optimizers(self):
optimizer = torch.optim.SGD(self.parameters(), lr=0.1)
return optimizer
chk = ModelCheckpoint(dirpath=tmpdir, save_last=True)
model = FinetuningBoringModel()
model.validation_step = None
callback = TestBackboneFinetuningWarningCallback(unfreeze_backbone_at_epoch=3, verbose=False)
with pytest.warns(UserWarning, match="Did you init your optimizer in"):
trainer = Trainer(limit_train_batches=1, default_root_dir=tmpdir, callbacks=[callback, chk], max_epochs=2)
trainer.fit(model)
assert model.backbone.has_been_used
trainer = Trainer(max_epochs=3)
trainer.fit(model, ckpt_path=chk.last_model_path)
def test_freeze_unfreeze_function(tmpdir):
"""Test freeze properly sets requires_grad on the modules."""
seed_everything(42)
class FreezeModel(LightningModule):
def __init__(self):
super().__init__()
self.backbone = nn.Sequential(nn.Linear(32, 32), nn.BatchNorm1d(32), nn.ReLU(), nn.Linear(32, 2))
model = FreezeModel()
BaseFinetuning.freeze(model, train_bn=True)
assert not model.backbone[0].weight.requires_grad
assert model.backbone[1].weight.requires_grad
assert not model.backbone[3].weight.requires_grad
BaseFinetuning.freeze(model, train_bn=False)
assert not model.backbone[0].weight.requires_grad
assert not model.backbone[1].weight.requires_grad
assert not model.backbone[3].weight.requires_grad
BaseFinetuning.make_trainable(model)
assert model.backbone[0].weight.requires_grad
assert model.backbone[1].weight.requires_grad
assert model.backbone[3].weight.requires_grad
BaseFinetuning.freeze(model.backbone[0], train_bn=False)
assert not model.backbone[0].weight.requires_grad
BaseFinetuning.freeze(([(model.backbone[1]), [model.backbone[3]]]), train_bn=True)
assert model.backbone[1].weight.requires_grad
assert not model.backbone[3].weight.requires_grad
def test_unfreeze_and_add_param_group_function(tmpdir):
"""Test unfreeze_and_add_param_group properly unfreeze parameters and add to the correct param_group."""
seed_everything(42)
class FreezeModel(LightningModule):
def __init__(self):
super().__init__()
self.backbone = nn.Sequential(
nn.Linear(32, 32, bias=False),
nn.Linear(32, 32, bias=False),
nn.Linear(32, 32, bias=False),
nn.Linear(32, 32, bias=False),
nn.Linear(32, 32, bias=False),
nn.BatchNorm1d(32),
)
model = FreezeModel()
optimizer = SGD(model.backbone[0].parameters(), lr=0.01)
with pytest.warns(UserWarning, match="The provided params to be frozen already"):
BaseFinetuning.unfreeze_and_add_param_group(model.backbone[0], optimizer=optimizer)
assert optimizer.param_groups[0]["lr"] == 0.01
model.backbone[1].weight.requires_grad = False
BaseFinetuning.unfreeze_and_add_param_group(model.backbone[1], optimizer=optimizer)
assert len(optimizer.param_groups) == 2
assert optimizer.param_groups[1]["lr"] == 0.001
assert torch.equal(optimizer.param_groups[1]["params"][0], model.backbone[1].weight)
assert model.backbone[1].weight.requires_grad
with pytest.warns(UserWarning, match="The provided params to be frozen already"):
BaseFinetuning.unfreeze_and_add_param_group(model, optimizer=optimizer, lr=100, train_bn=False)
assert len(optimizer.param_groups) == 3
assert optimizer.param_groups[2]["lr"] == 100
assert len(optimizer.param_groups[2]["params"]) == 3
for group_idx, group in enumerate(optimizer.param_groups):
if group_idx == 0:
assert torch.equal(optimizer.param_groups[0]["params"][0], model.backbone[0].weight)
if group_idx == 2:
assert torch.equal(optimizer.param_groups[2]["params"][0], model.backbone[2].weight)
assert torch.equal(optimizer.param_groups[2]["params"][1], model.backbone[3].weight)
assert torch.equal(optimizer.param_groups[2]["params"][2], model.backbone[4].weight)
class OnEpochLayerFinetuning(BaseFinetuning):
def freeze_before_training(self, pl_module: LightningModule):
self.freeze(pl_module.layer)
def finetune_function(self, pl_module: LightningModule, epoch: int, optimizer: Optimizer, opt_idx: int):
self.unfreeze_and_add_param_group(pl_module.layer[epoch + 1], optimizer)
def test_base_finetuning_internal_optimizer_metadata(tmpdir):
"""Test the param_groups updates are properly saved within the internal state of the BaseFinetuning
Callbacks."""
seed_everything(42)
class FreezeModel(BoringModel):
def __init__(self):
super().__init__()
self.layer = nn.Sequential(
nn.Linear(32, 32, bias=False),
nn.Linear(32, 32, bias=True),
nn.Linear(32, 32, bias=False),
nn.Linear(32, 32, bias=True),
nn.Linear(32, 32, bias=False),
nn.Linear(32, 2, bias=True),
)
def forward(self, x):
return self.layer(x)
def configure_optimizers(self):
return torch.optim.SGD(self.layer[0].parameters(), lr=0.1)
cb = OnEpochLayerFinetuning()
chk = ModelCheckpoint(dirpath=tmpdir, save_last=True)
model = FreezeModel()
trainer = Trainer(default_root_dir=tmpdir, max_epochs=5, limit_train_batches=1, callbacks=[cb, chk])
trainer.fit(model)
assert len(cb._internal_optimizer_metadata[0]) == 6
assert cb._internal_optimizer_metadata[0][0]["params"] == ["layer.0.weight"]
assert cb._internal_optimizer_metadata[0][1]["params"] == ["layer.1.weight", "layer.1.bias"]
assert cb._internal_optimizer_metadata[0][2]["params"] == ["layer.2.weight"]
assert cb._internal_optimizer_metadata[0][3]["params"] == ["layer.3.weight", "layer.3.bias"]
assert cb._internal_optimizer_metadata[0][4]["params"] == ["layer.4.weight"]
assert cb._internal_optimizer_metadata[0][5]["params"] == ["layer.5.weight", "layer.5.bias"]
model = FreezeModel()
cb = OnEpochLayerFinetuning()
trainer = Trainer(max_epochs=10, callbacks=[cb])
with pytest.raises(IndexError, match="index 6 is out of range"):
trainer.fit(model, ckpt_path=chk.last_model_path)
class ConvBlock(nn.Module):
def __init__(self, in_channels, out_channels):
super().__init__()
self.conv = nn.Conv2d(in_channels, out_channels, 3)
self.act = nn.ReLU()
self.bn = nn.BatchNorm2d(out_channels)
def forward(self, x):
x = self.conv(x)
x = self.act(x)
return self.bn(x)
class ConvBlockParam(nn.Module):
def __init__(self, in_channels, out_channels):
super().__init__()
self.module_dict = nn.ModuleDict({"conv": nn.Conv2d(in_channels, out_channels, 3), "act": nn.ReLU()})
# add trivial test parameter to convblock to validate parent (non-leaf) module parameter handling
self.parent_param = nn.Parameter(torch.zeros((1), dtype=torch.float))
self.bn = nn.BatchNorm2d(out_channels)
def forward(self, x):
x = self.module_dict["conv"](x)
x = self.module_dict["act"](x)
return self.bn(x)
def test_complex_nested_model():
"""Test flattening, freezing, and thawing of models which contain parent (non-leaf) modules with parameters
directly themselves rather than exclusively their submodules containing parameters."""
model = nn.Sequential(
OrderedDict(
[("encoder", nn.Sequential(ConvBlockParam(3, 64), ConvBlock(64, 128))), ("decoder", ConvBlock(128, 10))]
)
)
# There are 10 leaf modules or parent modules w/ parameters in the test model
assert len(BaseFinetuning.flatten_modules(model)) == 10
BaseFinetuning.freeze(model.encoder, train_bn=True)
assert not model.encoder[0].module_dict["conv"].weight.requires_grad # Validate a leaf module parameter is frozen
assert not model.encoder[0].parent_param.requires_grad # Validate the parent module parameter is frozen
assert model.encoder[0].bn.weight.requires_grad
BaseFinetuning.make_trainable(model)
encoder_params = list(BaseFinetuning.filter_params(model.encoder, train_bn=True))
# The 9 parameters of the encoder are:
# conv0.weight, conv0.bias, bn0.weight, bn0.bias, parent_param
# conv1.weight, conv1.bias, bn1.weight, bn1.bias
assert len(encoder_params) == 9
class TestCallbacksRestoreCallback(BaseFinetuning):
def freeze_before_training(self, pl_module):
self.freeze(pl_module.layer[:3])
def finetune_function(self, pl_module, epoch, optimizer, opt_idx):
if epoch >= 1:
self.unfreeze_and_add_param_group(pl_module.layer[epoch - 1], optimizer)
class FinetuningBoringModel(BoringModel):
def __init__(self):
super().__init__()
self.layer = nn.Sequential(nn.Linear(32, 32), nn.Linear(32, 32), nn.Linear(32, 32), nn.Linear(32, 2))
def configure_optimizers(self):
parameters = filter(lambda x: x.requires_grad, self.parameters())
optimizer = torch.optim.SGD(parameters, lr=0.1)
return optimizer
def test_callbacks_restore(tmpdir):
"""Test callbacks restore is called after optimizers have been re-created but before optimizer states
reload."""
chk = ModelCheckpoint(dirpath=tmpdir, save_last=True)
model = FinetuningBoringModel()
callback = TestCallbacksRestoreCallback()
trainer_kwargs = dict(
default_root_dir=tmpdir, limit_train_batches=1, limit_val_batches=1, callbacks=[callback, chk], max_epochs=2
)
trainer = Trainer(**trainer_kwargs)
trainer.fit(model)
# only 1 optimizer
assert len(callback._internal_optimizer_metadata) == 1
# only 2 param groups
assert len(callback._internal_optimizer_metadata[0]) == 2
# original parameters
expected = {
"lr": 0.1,
"momentum": 0,
"dampening": 0,
"weight_decay": 0,
"nesterov": False,
"params": ["layer.3.weight", "layer.3.bias"],
}
if _TORCH_GREATER_EQUAL_1_11:
expected["maximize"] = False
assert callback._internal_optimizer_metadata[0][0] == expected
# new param group
expected = {
"lr": 0.01,
"momentum": 0,
"dampening": 0,
"weight_decay": 0,
"nesterov": False,
"params": ["layer.0.weight", "layer.0.bias"],
}
if _TORCH_GREATER_EQUAL_1_11:
expected["maximize"] = False
assert callback._internal_optimizer_metadata[0][1] == expected
trainer_kwargs["max_epochs"] = 3
trainer = Trainer(**trainer_kwargs)
trainer.fit(model, ckpt_path=chk.last_model_path)
def test_callbacks_restore_backbone(tmpdir):
"""Test callbacks restore is called after optimizers have been re-created but before optimizer states
reload."""
class BackboneBoringModel(BoringModel):
def __init__(self):
super().__init__()
self.layer = nn.Linear(32, 2)
self.backbone = nn.Linear(32, 32)
def forward(self, x):
return self.layer(self.backbone(x))
ckpt = ModelCheckpoint(dirpath=tmpdir, save_last=True)
trainer = Trainer(
default_root_dir=tmpdir,
limit_train_batches=1,
limit_val_batches=1,
max_epochs=2,
enable_progress_bar=False,
callbacks=[ckpt, BackboneFinetuning(unfreeze_backbone_at_epoch=1)],
)
trainer.fit(BackboneBoringModel())
# initialize a trainer that continues the previous training
trainer = Trainer(
default_root_dir=tmpdir,
limit_train_batches=1,
limit_val_batches=1,
max_epochs=3,
enable_progress_bar=False,
callbacks=BackboneFinetuning(unfreeze_backbone_at_epoch=1),
)
trainer.fit(BackboneBoringModel(), ckpt_path=ckpt.last_model_path)