Validating Transformer Auto-Chunking Optimization in ColossalAI
This test suite validates the automatic chunking functionality in ColossalAI’s transformer implementation, focusing on memory optimization and code generation for large-scale models.
Test Coverage Overview
Implementation Analysis
Technical Details
Best Practices Demonstrated
hpcaitech/colossalai
tests/test_autochunk/test_autochunk_transformer/test_autochunk_transformer_utils.py
from typing import Any, Dict, List
import torch
import torch.fx
import colossalai
from colossalai.autochunk.autochunk_codegen import AUTOCHUNK_AVAILABLE
from colossalai.fx.graph_module import ColoGraphModule
from colossalai.fx.passes.meta_info_prop import MetaInfoProp
if AUTOCHUNK_AVAILABLE:
from colossalai.autochunk.autochunk_codegen import AutoChunkCodeGen
from colossalai.fx.profiler import MetaTensor
from colossalai.fx.tracer.experimental import ColoTracer, symbolic_trace
def assert_codegen_run(
model: Any,
data: tuple,
max_memory: int = None,
print_est_mem: bool = False,
print_mem: bool = False,
print_progress: bool = False,
print_code: bool = False,
eval_mem: bool = False,
) -> List[Dict]:
meta_args, concrete_args, sequence = data
if concrete_args is None:
concrete_args = {}
# trace the meta graph and setup codegen
meta_graph = symbolic_trace(
model,
meta_args={k: v.to(torch.device("meta")) for k, v in meta_args.items()},
concrete_args={k: v for k, v in concrete_args.items()},
)
interp = MetaInfoProp(meta_graph)
meta_tensors = [meta_args[i] if i in meta_args else concrete_args[i] for i in sequence]
meta_tensors = [MetaTensor(i, fake_device="cuda:0") if isinstance(i, torch.Tensor) else i for i in meta_tensors]
interp.propagate(*meta_tensors)
codegen = AutoChunkCodeGen(
meta_graph, max_memory=max_memory, print_mem=print_est_mem, print_progress=print_progress, eval_mem=eval_mem
)
chunks = codegen.chunk_infos
# trace and recompile
# MetaInfoProp requires symbolic_trace but CodeGen requires ColoTracer
graph = ColoTracer().trace(
model.cuda(),
meta_args={k: v.to(torch.device("meta")) for k, v in meta_args.items()},
concrete_args={k: v for k, v in concrete_args.items()},
)
graph.set_codegen(codegen)
gm = ColoGraphModule(model, graph, ckpt_codegen=False)
gm.recompile()
# assert chunk in code
code = graph.python_code("self").src
if print_code:
print(code)
assert "chunk_size = None; " in code
# assert result
inputs = [meta_args[i] if i in meta_args else concrete_args[i] for i in sequence]
inputs = [i.cuda() if isinstance(i, torch.Tensor) else i for i in inputs]
model.cuda().eval()
gm.eval()
with torch.no_grad():
if print_mem:
torch.cuda.reset_peak_memory_stats()
now_mem = torch.cuda.memory_allocated() / 1024**2
out_gm = gm(*[i.clone() if isinstance(i, torch.Tensor) else i for i in inputs])
if print_mem:
new_max_mem = torch.cuda.max_memory_allocated() / 1024**2
print("mem: %.2fMB" % (new_max_mem - now_mem))
out_model = model(*inputs)
assert_allclose(out_model, out_gm)
return chunks
def assert_allclose(out_model: Any, out_gm: Any) -> None:
"""
assert allclose for out
"""
if isinstance(out_model, torch.Tensor):
assert torch.allclose(
out_model, out_gm, atol=1e-4
), "fx_out doesn't comply with original output, diff is %.2e" % torch.mean(torch.abs(out_model - out_gm))
elif isinstance(out_model, dict):
for k in out_model.keys():
assert_allclose(out_model[k], out_gm[k])
elif isinstance(out_model, tuple) or isinstance(out_model, list) or isinstance(out_model, set):
for i, j in zip(out_model, out_gm):
assert_allclose(i, j)
def run_test(
rank: int,
world_size: int,
port: int,
model: Any,
config: Any,
data: tuple,
max_memory: int,
print_code: bool = False,
print_est_mem: bool = False,
print_mem: bool = False,
print_progress: bool = False,
eval_mem: bool = False,
get_chunk_target: Any = None,
) -> None:
model = model(config=config)
# launch colossalai
colossalai.launch(
config={},
rank=rank,
world_size=world_size,
host="localhost",
port=port,
backend="nccl",
)
# build model and input
chunks = assert_codegen_run(
model,
data=data,
max_memory=max_memory,
print_code=print_code,
print_est_mem=print_est_mem,
print_mem=print_mem,
print_progress=print_progress,
eval_mem=eval_mem,
)
if get_chunk_target is not None:
chunk_found = [i["region"] for i in chunks]
chunk_target = get_chunk_target()[max_memory]
assert chunk_found == chunk_target, "found regions %s doesn't equal target regions %s" % (
str(chunk_found),
str(chunk_target),
)