fix pp comm init bug (#36377)

python/paddle/distributed/auto_parallel/reshard.py

@@ -662,7 +662,10 @@ def _concat_partitions_with_op(partition_tensor_list, tensor, partition_index,
 
 
 def _init_comm_for_send_recv():
-    if not PROCESS_GROUP_MAP["global_group"].is_instantiate():
+    if not PROCESS_GROUP_MAP:
+        genv = _get_global_env()
+        PROCESS_GROUP_MAP["global_group"] = ProcessGroup(
+            0, list(range(genv.world_size)))
         PROCESS_GROUP_MAP["global_group"].instantiate()
 
 

python/paddle/fluid/tests/unittests/test_auto_parallel_reshard.py

@@ -27,6 +27,7 @@ from paddle.distributed import fleet
 from paddle.distributed.auto_parallel.partitioner import Partitioner
 from paddle.distributed.auto_parallel.completion import complete_backward_annotation
 from paddle.distributed.auto_parallel.reshard import reshard
+from paddle.distributed.auto_parallel.process import PROCESS_GROUP_MAP
 
 paddle.enable_static()
 _global_parallel_strategy = None
@@ -254,6 +255,8 @@ class TestMLPReshard(unittest.TestCase):
         dist_main_prog, dist_startup_prog = get_dist_prog(
             train_program, startup_program, dist_context, rank_id)
         complete_backward_annotation(dist_main_prog, dist_context)
+        for key in list(PROCESS_GROUP_MAP.keys()):
+            del PROCESS_GROUP_MAP[key]
         reshard(dist_main_prog, dist_startup_prog, rank_id, dist_context)
 
         # check send and recv result