| 1 | # SPDX-License-Identifier: Apache-2.0 |
| 2 | # SPDX-FileCopyrightText: Copyright contributors to the vLLM project |
| 3 | |
| 4 | import random |
| 5 | import typing |
| 6 | |
| 7 | import pytest |
| 8 | import torch |
| 9 | import torch.distributed as dist |
| 10 | import torch.multiprocessing as mp |
| 11 | |
| 12 | import vllm.envs as envs |
| 13 | from tests.utils import ensure_current_vllm_config |
| 14 | from vllm.distributed import cleanup_dist_env_and_memory |
| 15 | from vllm.distributed.device_communicators.cuda_communicator import CudaCommunicator |
| 16 | from vllm.distributed.device_communicators.pynccl import register_nccl_symmetric_ops |
| 17 | from vllm.distributed.device_communicators.pynccl_allocator import ( |
| 18 | get_nccl_mem_pool, |
| 19 | is_symmetric_memory_enabled, |
| 20 | ) |
| 21 | from vllm.distributed.parallel_state import ( |
| 22 | get_tp_group, |
| 23 | init_distributed_environment, |
| 24 | initialize_model_parallel, |
| 25 | ) |
| 26 | from vllm.platforms import current_platform |
| 27 | from vllm.utils.system_utils import update_environment_variables |
| 28 | |
| 29 | torch.manual_seed(42) |
| 30 | random.seed(44) |
| 31 | |
| 32 | test_size_elements = 4 * 1024 * 1024 |
| 33 | |
| 34 | |
| 35 | def nccl_symm_mem_allreduce_worker(local_rank: int, world_size: int): |
| 36 | monkeypatch = pytest.MonkeyPatch() |
| 37 | with monkeypatch.context() as m: |
| 38 | m.delenv("CUDA_VISIBLE_DEVICES", raising=False) |
| 39 | dtype = torch.bfloat16 |
| 40 | device = torch.device(f"cuda:{local_rank}") |
| 41 | torch.accelerator.set_device_index(device) |
| 42 | torch.set_default_device(device) |
| 43 | torch.set_default_dtype(dtype) |
| 44 | update_environment_variables( |
| 45 | { |
| 46 | "RANK": str(local_rank), |
| 47 | "LOCAL_RANK": str(local_rank), |
| 48 | "WORLD_SIZE": str(world_size), |
| 49 | "MASTER_ADDR": "localhost", |
| 50 | "MASTER_PORT": "12345", |
| 51 | } |
| 52 | ) |
| 53 | |
| 54 | init_distributed_environment() |
| 55 | with ensure_current_vllm_config(): |
| 56 | initialize_model_parallel(tensor_model_parallel_size=world_size) |
| 57 | |
| 58 | cuda_communicator = typing.cast( |
| 59 | CudaCommunicator, get_tp_group().device_communicator |
| 60 | ) |
| 61 | pynccl_comm = cuda_communicator.pynccl_comm |
| 62 | if get_nccl_mem_pool() is None: |
| 63 | pytest.skip( |
| 64 | "NCCL allocator compilation failed (probably missing NCCL headers)." |
| 65 | ) |
| 66 | if not is_symmetric_memory_enabled(): |
| 67 | pytest.skip("NCCL symmetric memory allreduce is disabled.") |
| 68 | |
| 69 | register_nccl_symmetric_ops(pynccl_comm) |
| 70 | input = torch.randint(1, 23, (test_size_elements,), dtype=dtype, device=device) |
| 71 | input_clone = input.clone() |
| 72 | output = torch.ops.vllm.all_reduce_symmetric_with_copy(input) |
| 73 | assert output is not None |
| 74 | |
| 75 | group = get_tp_group().device_group |
| 76 | dist.all_reduce(input_clone, group=group) |
| 77 | torch.testing.assert_close(output, input_clone, atol=2.5, rtol=0.1) |
| 78 | |
| 79 | |
| 80 | @pytest.mark.skipif( |
| 81 | not current_platform.is_cuda(), |
| 82 | reason="NCCLSymmMemAllreduce is only available for CUDA platforms.", |
| 83 | ) |
| 84 | @pytest.mark.parametrize("world_size", [2]) |
| 85 | @pytest.mark.skipif(envs.VLLM_TARGET_DEVICE not in ["cuda"], reason="Only test on CUDA") |
| 86 | def test_nccl_symm_mem_allreduce(monkeypatch: pytest.MonkeyPatch, world_size): |
| 87 | if world_size > torch.accelerator.device_count(): |
| 88 | pytest.skip("Not enough GPUs to run the test.") |
| 89 | |
| 90 | # Enable SymmMemCommunicator |
| 91 | monkeypatch.setenv("VLLM_USE_NCCL_SYMM_MEM", "1") |
| 92 | monkeypatch.setenv("NCCL_NVLS_ENABLE", "1") |
| 93 | monkeypatch.setenv("NCCL_CUMEM_ENABLE", "1") |
| 94 | |
| 95 | mp.spawn(nccl_symm_mem_allreduce_worker, args=(world_size,), nprocs=world_size) |
| 96 | cleanup_dist_env_and_memory() |
| 97 | |
| 98 | |
| 99 | def nccl_symm_mem_allgather_worker(local_rank: int, world_size: int): |
| 100 | monkeypatch = pytest.MonkeyPatch() |
| 101 | with monkeypatch.context() as m: |
| 102 | m.delenv("CUDA_VISIBLE_DEVICES", raising=False) |
| 103 | dtype = torch.bfloat16 |
| 104 | device = torch.device(f"cuda:{local_rank}") |
| 105 | torch.accelerator.set_device_index(device) |
| 106 | torch.set_default_device(device) |
| 107 | torch.set_default_dtype(dtype) |
| 108 | update_environment_variables( |
| 109 | { |
| 110 | "RANK": str(local_rank), |
| 111 | "LOCAL_RANK": str(local_rank), |
| 112 | "WORLD_SIZE": str(world_size), |
| 113 | "MASTER_ADDR": "localhost", |
| 114 | "MASTER_PORT": "12346", |
| 115 | } |
| 116 | ) |
| 117 | |
| 118 | init_distributed_environment() |
| 119 | with ensure_current_vllm_config(): |
| 120 | initialize_model_parallel(tensor_model_parallel_size=world_size) |
| 121 | |
| 122 | cuda_communicator = typing.cast( |
| 123 | CudaCommunicator, get_tp_group().device_communicator |
| 124 | ) |
| 125 | if get_nccl_mem_pool() is None: |
| 126 | pytest.skip( |
| 127 | "NCCL allocator compilation failed (probably missing NCCL headers)." |
| 128 | ) |
| 129 | if not is_symmetric_memory_enabled(): |
| 130 | pytest.skip("NCCL symmetric memory is disabled.") |
| 131 | |
| 132 | per_rank_size = test_size_elements // world_size |
| 133 | input_tensor = torch.randint( |
| 134 | 1, 23, (per_rank_size,), dtype=dtype, device=device |
| 135 | ) |
| 136 | output = cuda_communicator.all_gatherv(input_tensor, dim=0) |
| 137 | |
| 138 | group = get_tp_group().device_group |
| 139 | expected = torch.empty(test_size_elements, dtype=dtype, device=device) |
| 140 | dist.all_gather_into_tensor(expected, input_tensor, group=group) |
| 141 | torch.testing.assert_close(output, expected, atol=0.0, rtol=0.0) |
| 142 | |
| 143 | |
| 144 | @pytest.mark.skipif( |
| 145 | not current_platform.is_cuda(), |
| 146 | reason="NCCL symmetric memory is only available for CUDA platforms.", |
| 147 | ) |
| 148 | @pytest.mark.parametrize("world_size", [2]) |
| 149 | @pytest.mark.skipif(envs.VLLM_TARGET_DEVICE not in ["cuda"], reason="Only test on CUDA") |
| 150 | def test_nccl_symm_mem_allgather(monkeypatch: pytest.MonkeyPatch, world_size): |
| 151 | if world_size > torch.accelerator.device_count(): |
| 152 | pytest.skip("Not enough GPUs to run the test.") |
| 153 | |
| 154 | monkeypatch.setenv("VLLM_USE_NCCL_SYMM_MEM", "1") |
| 155 | monkeypatch.setenv("NCCL_NVLS_ENABLE", "1") |
| 156 | monkeypatch.setenv("NCCL_CUMEM_ENABLE", "1") |
| 157 | |
| 158 | mp.spawn(nccl_symm_mem_allgather_worker, args=(world_size,), nprocs=world_size) |
| 159 | cleanup_dist_env_and_memory() |
| 160 | |
| 161 | |
| 162 | def nccl_symm_mem_reduce_scatter_worker(local_rank: int, world_size: int): |
| 163 | monkeypatch = pytest.MonkeyPatch() |
| 164 | with monkeypatch.context() as m: |
| 165 | m.delenv("CUDA_VISIBLE_DEVICES", raising=False) |
| 166 | dtype = torch.bfloat16 |
| 167 | device = torch.device(f"cuda:{local_rank}") |
| 168 | torch.accelerator.set_device_index(device) |
| 169 | torch.set_default_device(device) |
| 170 | torch.set_default_dtype(dtype) |
| 171 | update_environment_variables( |
| 172 | { |
| 173 | "RANK": str(local_rank), |
| 174 | "LOCAL_RANK": str(local_rank), |
| 175 | "WORLD_SIZE": str(world_size), |
| 176 | "MASTER_ADDR": "localhost", |
| 177 | "MASTER_PORT": "12347", |
| 178 | } |
| 179 | ) |
| 180 | |
| 181 | init_distributed_environment() |
| 182 | with ensure_current_vllm_config(): |
| 183 | initialize_model_parallel(tensor_model_parallel_size=world_size) |
| 184 | |
| 185 | cuda_communicator = typing.cast( |
| 186 | CudaCommunicator, get_tp_group().device_communicator |
| 187 | ) |
| 188 | if get_nccl_mem_pool() is None: |
| 189 | pytest.skip( |
| 190 | "NCCL allocator compilation failed (probably missing NCCL headers)." |
| 191 | ) |
| 192 | if not is_symmetric_memory_enabled(): |
| 193 | pytest.skip("NCCL symmetric memory is disabled.") |
| 194 | |
| 195 | per_rank_size = test_size_elements // world_size |
| 196 | input_tensor = torch.randint( |
| 197 | 1, 23, (test_size_elements,), dtype=dtype, device=device |
| 198 | ) |
| 199 | input_clone = input_tensor.clone() |
| 200 | output = cuda_communicator.reduce_scatter(input_tensor, dim=0) |
| 201 | |
| 202 | group = get_tp_group().device_group |
| 203 | expected = torch.empty(per_rank_size, dtype=dtype, device=device) |
| 204 | dist.reduce_scatter_tensor(expected, input_clone, group=group) |
| 205 | torch.testing.assert_close(output, expected, atol=2.5, rtol=0.1) |
| 206 | |
| 207 | |
| 208 | @pytest.mark.skipif( |
| 209 | not current_platform.is_cuda(), |
| 210 | reason="NCCL symmetric memory is only available for CUDA platforms.", |
| 211 | ) |
| 212 | @pytest.mark.parametrize("world_size", [2]) |
| 213 | @pytest.mark.skipif(envs.VLLM_TARGET_DEVICE not in ["cuda"], reason="Only test on CUDA") |
| 214 | def test_nccl_symm_mem_reduce_scatter(monkeypatch: pytest.MonkeyPatch, world_size): |
| 215 | if world_size > torch.accelerator.device_count(): |
| 216 | pytest.skip("Not enough GPUs to run the test.") |
| 217 | |
| 218 | monkeypatch.setenv("VLLM_USE_NCCL_SYMM_MEM", "1") |
| 219 | monkeypatch.setenv("NCCL_NVLS_ENABLE", "1") |
| 220 | monkeypatch.setenv("NCCL_CUMEM_ENABLE", "1") |
| 221 | |
| 222 | mp.spawn(nccl_symm_mem_reduce_scatter_worker, args=(world_size,), nprocs=world_size) |
| 223 | cleanup_dist_env_and_memory() |