fix global gather (#48736)

python/paddle/fluid/tests/unittests/collective/collective_global_gather.py

@@ -22,7 +22,6 @@ from test_collective_api_base import TestCollectiveAPIRunnerBase, runtime_main
 import paddle
 import paddle.distributed.utils.moe_utils as moe_utils
 import paddle.fluid as fluid
-from paddle.fluid.framework import _enable_legacy_dygraph
 
 paddle.enable_static()
 
@@ -61,8 +60,8 @@ class TestCollectiveGlobalGatherAPI(TestCollectiveAPIRunnerBase):
         endpoints = args["endpoints"].split(",")
         rank = args["trainerid"]
         current_endpoint = args["currentendpoint"]
-        nranks = 2
         paddle.distributed.init_parallel_env()
+        nranks = 2
         if args['backend'] == 'nccl':
             device_id = int(os.getenv("FLAGS_selected_gpus", "0"))
             place = fluid.CUDAPlace(
@@ -78,33 +77,37 @@ class TestCollectiveGlobalGatherAPI(TestCollectiveAPIRunnerBase):
         n_expert = 2
         world_size = 2
         tot_expert = n_expert * world_size
-        paddle.disable_static()
 
-        # Call paddle.distributed.alltoall() under legacy dygraph
-        _enable_legacy_dygraph()
+        tmp_main_prog = fluid.Program()
+        with fluid.program_guard(tmp_main_prog, fluid.Program()):
+            local_expert_count = paddle.static.data(
+                name="local_expert_count", shape=[tot_expert], dtype="int64"
+            )
+            global_expert_count = []
+            paddle.distributed.alltoall(
+                paddle.split(local_expert_count, 2, axis=0), global_expert_count
+            )
+            global_expert_count = paddle.concat(global_expert_count, axis=0)
+        exe = fluid.Executor(place)
+        exe.run(startup_prog)
         np.random.seed(os.getpid())
         local_expert_count = np.random.randint(1, 4, size=tot_expert).astype(
             "int64"
         )
-        local_expert_count = paddle.to_tensor(local_expert_count)
-        global_expert_count = []
-        paddle.distributed.alltoall(
-            paddle.split(local_expert_count, 2, axis=0), global_expert_count
+        (global_expert_count,) = exe.run(
+            tmp_main_prog,
+            feed={"local_expert_count": local_expert_count},
+            fetch_list=[global_expert_count.name],
         )
-        global_expert_count = paddle.concat(global_expert_count, axis=0)
-        global_expert_count = global_expert_count.numpy()
-        local_expert_count = local_expert_count.numpy()
+
         fwd_expert_count = sum(global_expert_count)
         np.random.seed(os.getpid())
         local_input_buf = np.random.rand(fwd_expert_count, in_feat).astype(
             "float32"
         )
 
-        paddle.enable_static()
         if args['static_mode']:
             result = self.get_model(train_prog, startup_prog, rank)
-            exe = fluid.Executor(place)
-            exe.run(startup_prog)
             fetch_list = []
             for elem in result:
                 fetch_list.append(elem.name)