lightning/tests/plugins/test_amp_plugins.py

85 lines
2.4 KiB
Python

import os
from unittest import mock
import pytest
import torch
from pytorch_lightning import Trainer
from pytorch_lightning.plugins import ApexMixedPrecisionPlugin, NativeMixedPrecisionPlugin
from pytorch_lightning.plugins.precision import MixedPrecisionPlugin
from tests.helpers import BoringModel
from tests.helpers.runif import RunIf
class MyNativeAMP(NativeMixedPrecisionPlugin):
pass
class MyApexPlugin(ApexMixedPrecisionPlugin):
pass
@mock.patch.dict(
os.environ, {
"CUDA_VISIBLE_DEVICES": "0,1",
"SLURM_NTASKS": "2",
"SLURM_JOB_NAME": "SOME_NAME",
"SLURM_NODEID": "0",
"LOCAL_RANK": "0",
"SLURM_LOCALID": "0",
}
)
@mock.patch('torch.cuda.device_count', return_value=2)
@pytest.mark.parametrize('ddp_backend,gpus', [('ddp', 2), ('ddp2', 2), ('ddp_spawn', 2)])
@pytest.mark.parametrize(
'amp,custom_plugin,plugin_cls', [
pytest.param('native', False, NativeMixedPrecisionPlugin, marks=RunIf(amp_native=True)),
pytest.param('native', True, MyNativeAMP, marks=RunIf(amp_native=True)),
pytest.param('apex', False, ApexMixedPrecisionPlugin, marks=RunIf(amp_apex=True)),
pytest.param('apex', True, MyApexPlugin, marks=RunIf(amp_apex=True))
]
)
def test_amp_apex_ddp(
mocked_device_count, ddp_backend: str, gpus: int, amp: str, custom_plugin: bool, plugin_cls: MixedPrecisionPlugin
):
trainer = Trainer(
fast_dev_run=True,
precision=16,
amp_backend=amp,
gpus=gpus,
accelerator=ddp_backend,
plugins=[plugin_cls()] if custom_plugin else None,
)
assert isinstance(trainer.precision_plugin, plugin_cls)
class GradientUnscaleBoringModel(BoringModel):
def on_after_backward(self):
norm = torch.nn.utils.clip_grad_norm_(self.parameters(), 2)
if not (torch.isinf(norm) or torch.isnan(norm)):
assert norm.item() < 15.
@RunIf(min_gpus=2, amp_native=True)
@pytest.mark.parametrize('accum', [1, 2])
def test_amp_gradient_unscale(tmpdir, accum: int):
model = GradientUnscaleBoringModel()
trainer = Trainer(
max_epochs=2,
default_root_dir=tmpdir,
limit_train_batches=2,
limit_test_batches=2,
limit_val_batches=2,
amp_backend='native',
accelerator='ddp_spawn',
gpus=2,
precision=16,
track_grad_norm=2,
log_every_n_steps=1,
accumulate_grad_batches=accum,
)
trainer.fit(model)