vllm/tests/distributed/test_comm_ops.py
2023-12-27 17:18:11 -05:00

84 lines
3.2 KiB
Python

"""Test the communication operators.
Run `pytest tests/distributed/test_comm_ops.py --forked`.
"""
from multiprocessing import Process, set_start_method
import pytest
import torch
from vllm.config import ParallelConfig
from vllm.utils import get_open_port
from vllm.model_executor.parallel_utils.communication_op import (
tensor_model_parallel_all_reduce,
tensor_model_parallel_all_gather,
)
from vllm.worker.worker import _init_distributed_environment
def init_test_distributed_environment(pipeline_parallel_size: int,
tensor_parallel_size: int, rank: int,
distributed_init_port: str):
parallel_config = ParallelConfig(pipeline_parallel_size,
tensor_parallel_size,
worker_use_ray=True)
distributed_init_method = f"tcp://localhost:{distributed_init_port}"
torch.cuda.set_device(rank)
_init_distributed_environment(parallel_config, rank,
distributed_init_method)
def all_reduce_test_worker(tensor_parallel_size: int, rank: int,
distributed_init_port: str):
init_test_distributed_environment(1, tensor_parallel_size, rank,
distributed_init_port)
num_elements = 8
all_tensors = [
torch.arange(num_elements, dtype=torch.float32, device="cuda") *
(r + 1) for r in range(tensor_parallel_size)
]
expected = torch.sum(torch.stack(all_tensors, dim=0), dim=0)
t = all_tensors[rank]
t = tensor_model_parallel_all_reduce(t)
assert torch.allclose(t, expected)
def all_gather_test_worker(tensor_parallel_size: int, rank: int,
distributed_init_port: str):
init_test_distributed_environment(1, tensor_parallel_size, rank,
distributed_init_port)
num_dimensions = 3
tensor_size = list(range(2, num_dimensions + 2))
total_size = 1
for s in tensor_size:
total_size *= s
for all_gather_dimension in range(num_dimensions):
all_tensors = [
torch.arange(total_size, dtype=torch.float32,
device="cuda").reshape(tensor_size) * (r + 1)
for r in range(tensor_parallel_size)
]
expected = torch.cat(all_tensors, dim=all_gather_dimension)
t = all_tensors[rank]
t = tensor_model_parallel_all_gather(t, all_gather_dimension)
assert torch.allclose(t, expected)
@pytest.mark.skipif(torch.cuda.device_count() < 2,
reason="Need at least 2 GPUs to run the test.")
@pytest.mark.parametrize("tensor_parallel_size", [2])
@pytest.mark.parametrize("test_target",
[all_reduce_test_worker, all_gather_test_worker])
def test_multi_process_tensor_parallel(tensor_parallel_size, test_target):
set_start_method("spawn", force=True)
distributed_init_port = get_open_port()
processes = []
for rank in range(tensor_parallel_size):
p = Process(target=test_target,
args=(tensor_parallel_size, rank, distributed_init_port))
p.start()
processes.append(p)
for p in processes:
p.join()
assert all(p.exitcode == 0 for p in processes)