ColossalAI/tests/test_zero/test_gemini/test_grad_accum.py

163 lines
5.8 KiB
Python

import pytest
import torch
import torch.distributed as dist
from apex import amp
from torch.nn.parallel import DistributedDataParallel as DDP
from torch.testing import assert_close
import colossalai
from colossalai.accelerator import get_accelerator
from colossalai.nn.optimizer import HybridAdam
from colossalai.testing import DummyDataloader, parameterize, rerun_if_address_is_in_use, spawn
from colossalai.utils import set_seed
from colossalai.zero import GeminiDDP, GeminiOptimizer
from colossalai.zero.gemini.chunk import search_chunk_configuration
from tests.kit.model_zoo import model_zoo, run_fwd
PLACEMENT_CONFIGS = [
{"placement_policy": "static", "shard_param_frac": 0.75},
{"placement_policy": "auto"},
]
def check_grad(model: GeminiDDP, torch_model: torch.nn.Module):
chunk_manager = model.chunk_manager
grad_chunk_list = []
device_list = []
# Access gradient chunks.
for p in model.parameters():
grad_chunk = chunk_manager.get_chunk(p).grad_chunk
if grad_chunk not in grad_chunk_list:
chunk_manager.access_chunk(grad_chunk)
grad_chunk_list.append(grad_chunk)
device_list.append(model.grads_device[p])
# Compare gradients.
for p0, p1 in zip(model.parameters(), torch_model.parameters()):
assert_close(p0, p1.grad, rtol=2e-3, atol=2e-2)
# Release gradient chunks and move them to gradient device.
for grad_chunk, device in zip(grad_chunk_list, device_list):
chunk_manager.release_chunk(grad_chunk)
chunk_manager.move_chunk(grad_chunk, device, force_copy=True)
@parameterize("placement_config", PLACEMENT_CONFIGS)
@parameterize("keep_gathered", [False, True])
@parameterize("model_name", ["transformers_gpt_lm"])
@parameterize("master_weights", [False, True])
@parameterize("use_grad_checkpoint", [False, True])
@parameterize("max_prefetch", [0, 4])
@parameterize("enable_async_reduce", [False, True])
def exam_gemini_grad_acc(
placement_config,
keep_gathered: bool,
model_name: str,
master_weights: bool,
use_grad_checkpoint: bool,
max_prefetch: int,
enable_async_reduce: bool,
):
init_device = get_accelerator().get_current_device()
model_builder, data_gen_fn, output_transform_fn, loss_fn, *_ = next(
iter(model_zoo.get_sub_registry(model_name).values())
)
set_seed(42)
gemini_model = model_builder()
set_seed(42)
torch_model = model_builder().cuda()
for torch_p, p in zip(torch_model.parameters(), gemini_model.parameters()):
torch_p.data.copy_(p.data)
if use_grad_checkpoint:
gemini_model.gradient_checkpointing_enable()
torch_model.gradient_checkpointing_enable()
world_size = torch.distributed.get_world_size()
config_dict, *_ = search_chunk_configuration(gemini_model, search_range_m=1, search_interval=100)
config_dict[world_size]["chunk_size"] = 5000
config_dict[world_size]["keep_gathered"] = keep_gathered
gemini_model = GeminiDDP(
gemini_model,
config_dict,
init_device,
pin_memory=True,
enable_gradient_accumulation=True,
master_weights=master_weights,
max_prefetch=max_prefetch,
enable_async_reduce=enable_async_reduce,
**placement_config,
)
optimizer = HybridAdam(gemini_model.parameters(), lr=1e-3)
gemini_optim = GeminiOptimizer(
optimizer, gemini_model, initial_scale=1, max_norm=1.0, enable_async_reduce=enable_async_reduce
)
rank = dist.get_rank()
# setting master_weights to False will cause overflow after optimizer.step()
amp_config = dict(
opt_level="O2", keep_batchnorm_fp32=False, loss_scale=1, min_loss_scale=1, max_loss_scale=1, master_weights=True
)
torch_optim = torch.optim.Adam(torch_model.parameters(), lr=1e-3)
torch_model, torch_optim = amp.initialize(torch_model, torch_optim, **amp_config)
torch_model = DDP(torch_model, device_ids=[rank])
set_seed(rank)
accum_iter = 2
train_dataloader = DummyDataloader(data_gen_fn)
for i, data in enumerate(train_dataloader):
delay_unscale = False if (i + 1) % accum_iter == 0 else True
data = {k: v.cuda() if isinstance(v, torch.Tensor) else v for k, v in data.items()}
set_seed(42 + rank)
torch_loss = run_fwd(torch_model, data, output_transform_fn, loss_fn)
torch_loss = torch_loss / accum_iter
with amp.scale_loss(torch_loss, torch_optim, delay_unscale=delay_unscale) as scaled_loss:
scaled_loss.backward()
set_seed(42 + rank)
gemini_loss = run_fwd(gemini_model, data, output_transform_fn, loss_fn)
gemini_loss = gemini_loss / accum_iter
gemini_optim.backward(gemini_loss)
assert torch.allclose(torch_loss.float(), gemini_loss.float(), rtol=1e-3, atol=1e-5)
check_grad(gemini_model, torch_model)
if (i + 1) % accum_iter == 0:
torch.nn.utils.clip_grad_norm_(amp.master_params(torch_optim), 1.0)
torch_optim.step()
gemini_optim.step()
torch_optim.zero_grad()
# check updated param
torch_dict = torch_model.state_dict()
gemini_dict = gemini_model.state_dict(only_rank_0=False)
for key, value in gemini_dict.items():
torch_key = "module." + key
torch_value = torch_dict[torch_key].to(value.device).to(value.dtype)
assert_close(value, torch_value, rtol=1e-3, atol=2e-3)
if i == accum_iter:
break
def run_dist(rank, world_size, port):
colossalai.launch(rank=rank, world_size=world_size, host="localhost", port=port, backend="nccl")
exam_gemini_grad_acc()
@pytest.mark.dist
@rerun_if_address_is_in_use()
def test_grad_accumulation():
spawn(run_dist, 2)
if __name__ == "__main__":
test_grad_accumulation()