fix allreduce test (#4909)

sgl-kernel/tests/test_trt_allreduce.py

 import ctypes
-import logging
+import multiprocessing as mp
 import random
 import socket
-import time
 import unittest
 from typing import Any, List, Optional
 
-import ray
 import sgl_kernel.allreduce as custom_ops
 import torch
 import torch.distributed as dist
 from torch.distributed import ProcessGroup
-from vllm import _custom_ops as vllm_ops
 
 from sglang.srt.distributed.device_communicators.cuda_wrapper import CudaRTLibrary
 
-logger = logging.getLogger(__name__)
-
 
 def get_open_port() -> int:
     # try ipv4
@@ -33,22 +28,21 @@ def get_open_port() -> int:
 
 def multi_process_parallel(
     world_size: int,
-    cls: Any,
     test_target: Any,
 ) -> None:
-    # Using ray helps debugging the error when it failed
-    # as compared to multiprocessing.
-    # NOTE: We need to set working_dir for distributed tests,
-    # otherwise we may get import errors on ray workers
-    ray.init(log_to_driver=True)
-
+    procs = []
     distributed_init_port = get_open_port()
-    refs = []
-    for rank in range(world_size):
-        refs.append(test_target.remote(cls, world_size, rank, distributed_init_port))
-    ray.get(refs)
+    for i in range(world_size):
+        proc = mp.Process(
+            target=test_target,
+            args=(world_size, i, distributed_init_port),
+        )
+        proc.start()
+        procs.append(proc)
 
-    ray.shutdown()
+    for i in range(world_size):
+        procs[i].join()
+        assert procs[i].exitcode == 0
 
 
 class TestCustomAllReduce(unittest.TestCase):
@@ -95,13 +89,8 @@ class TestCustomAllReduce(unittest.TestCase):
         for world_size in self.world_sizes:
             if world_size > torch.cuda.device_count():
                 continue
-            multi_process_parallel(world_size, self, self.correctness)
-
-    def test_performance(self):
-        for world_size in self.world_sizes:
-            if world_size > torch.cuda.device_count():
-                continue
-            multi_process_parallel(world_size, self, self.performance)
+            multi_process_parallel(world_size, self.correctness)
+            print(f"custom allreduce tp = {world_size}: OK")
 
     def init_custom_allreduce(self, rank, world_size, group):
         buffer_max_size = 8 * 1024 * 1024
@@ -137,37 +126,6 @@ class TestCustomAllReduce(unittest.TestCase):
         self.free_shared_buffer(self.barrier_out_ptrs, group)
         custom_ops.custom_dispose(self.custom_ptr)
 
-    def init_vllm_allreduce(self, rank, group):
-        self.vllm_rank = rank
-        self.vllm_max_size = 8 * 1024 * 1024
-        self.vllm_meta_ptrs = self.create_shared_buffer(
-            vllm_ops.meta_size() + self.vllm_max_size, group=group
-        )
-        self.vllm_buffer_ptrs = self.create_shared_buffer(
-            self.vllm_max_size, group=group
-        )
-        self.vllm_rank_data = torch.empty(
-            8 * 1024 * 1024, dtype=torch.uint8, device=torch.device("cuda:0")
-        )
-        self.vllm_ptr = vllm_ops.init_custom_ar(
-            self.vllm_meta_ptrs, self.vllm_rank_data, rank, True
-        )
-        vllm_ops.register_buffer(self.vllm_ptr, self.vllm_buffer_ptrs)
-
-    def vllm_allreduce(self, inp, out):
-        vllm_ops.all_reduce(
-            self.vllm_ptr,
-            inp,
-            out,
-            self.vllm_buffer_ptrs[self.vllm_rank],
-            self.vllm_max_size,
-        )
-
-    def free_vllm_allreduce(self, group):
-        vllm_ops.dispose(self.vllm_ptr)
-        self.free_shared_buffer(self.vllm_meta_ptrs, group)
-        self.free_shared_buffer(self.vllm_buffer_ptrs, group)
-
     @staticmethod
     def init_distributed_env(world_size, rank, distributed_init_port):
         device = torch.device("cuda:0")
@@ -184,7 +142,6 @@ class TestCustomAllReduce(unittest.TestCase):
         return group
 
     # compare result with torch.distributed
-    @ray.remote(num_gpus=1, max_calls=1)
     def correctness(self, world_size, rank, distributed_init_port):
         group = self.init_distributed_env(world_size, rank, distributed_init_port)
 
@@ -205,40 +162,6 @@ class TestCustomAllReduce(unittest.TestCase):
 
         self.free_custom_allreduce(group)
 
-    # compare performance with vllm
-    @ray.remote(num_gpus=1, max_calls=1)
-    def performance(self, world_size, rank, distributed_init_port):
-        group = self.init_distributed_env(world_size, rank, distributed_init_port)
-
-        self.init_vllm_allreduce(rank, group)
-        self.init_custom_allreduce(rank=rank, world_size=world_size, group=group)
-
-        for sz in self.test_sizes:
-            inp1 = torch.randint(
-                1, 16, (sz,), dtype=torch.float32, device=torch.cuda.current_device()
-            )
-            out1 = torch.empty_like(inp1)
-            test_loop = 5000
-            start = time.time()
-            for _ in range(test_loop):
-                self.custom_allreduce(inp1, out1)
-            elapse_custom = time.time() - start
-
-            start = time.time()
-            for _ in range(test_loop):
-                self.vllm_allreduce(inp1, out1)
-            elapse_vllm = time.time() - start
-
-            if rank == 0:
-                logger.warning(
-                    f"test_size = {sz}, world_size = {world_size}, "
-                    f"vllm time = {elapse_vllm * 1000 / test_loop:.4f}ms, "
-                    f"custom time = {elapse_custom * 1000 / test_loop:.4f}ms "
-                )
-
-        self.free_custom_allreduce(group)
-        self.free_vllm_allreduce(group)
-
 
 if __name__ == "__main__":
     unittest.main()