lightning/benchmarks/test_parity.py

117 lines
3.4 KiB
Python

import time
import numpy as np
import pytest
import torch
import tests.base.utils as tutils
from pytorch_lightning import Trainer, seed_everything
from tests.base.models import ParityModuleRNN, ParityModuleMNIST
@pytest.mark.parametrize('cls_model,max_diff', [
(ParityModuleRNN, 0.05),
(ParityModuleMNIST, 0.5)
])
@pytest.mark.skipif(not torch.cuda.is_available(), reason="test requires GPU machine")
def test_pytorch_parity(tmpdir, cls_model, max_diff):
"""
Verify that the same pytorch and lightning models achieve the same results
"""
num_epochs = 4
num_rums = 3
lightning_outs, pl_times = lightning_loop(cls_model, num_rums, num_epochs)
manual_outs, pt_times = vanilla_loop(cls_model, num_rums, num_epochs)
# make sure the losses match exactly to 5 decimal places
for pl_out, pt_out in zip(lightning_outs, manual_outs):
np.testing.assert_almost_equal(pl_out, pt_out, 5)
# the fist run initialize dataset (download & filter)
tutils.assert_speed_parity_absolute(pl_times[1:], pt_times[1:],
nb_epochs=num_epochs, max_diff=max_diff)
def vanilla_loop(cls_model, num_runs=10, num_epochs=10):
"""
Returns an array with the last loss from each epoch for each run
"""
device = torch.device('cuda' if torch.cuda.is_available() else "cpu")
errors = []
times = []
torch.backends.cudnn.deterministic = True
for i in range(num_runs):
time_start = time.perf_counter()
# set seed
seed = i
seed_everything(seed)
# init model parts
model = cls_model()
dl = model.train_dataloader()
optimizer = model.configure_optimizers()
# model to GPU
model = model.to(device)
epoch_losses = []
# as the first run is skipped, no need to run it long
for epoch in range(num_epochs if i > 0 else 1):
# run through full training set
for j, batch in enumerate(dl):
batch = [x.to(device) for x in batch]
loss_dict = model.training_step(batch, j)
loss = loss_dict['loss']
loss.backward()
optimizer.step()
optimizer.zero_grad()
# track last epoch loss
epoch_losses.append(loss.item())
time_end = time.perf_counter()
times.append(time_end - time_start)
errors.append(epoch_losses[-1])
return errors, times
def lightning_loop(cls_model, num_runs=10, num_epochs=10):
errors = []
times = []
for i in range(num_runs):
time_start = time.perf_counter()
# set seed
seed = i
seed_everything(seed)
model = cls_model()
# init model parts
trainer = Trainer(
# as the first run is skipped, no need to run it long
max_epochs=num_epochs if i > 0 else 1,
progress_bar_refresh_rate=0,
weights_summary=None,
gpus=1,
early_stop_callback=False,
checkpoint_callback=False,
deterministic=True,
logger=False,
replace_sampler_ddp=False,
)
trainer.fit(model)
final_loss = trainer.running_loss.last().item()
errors.append(final_loss)
time_end = time.perf_counter()
times.append(time_end - time_start)
return errors, times