!10656 [MD] Fix a rank id runtime error

From: @xiefangqi
Reviewed-by: @liucunwei,@pandoublefeng
Signed-off-by: @liucunwei

mindspore/dataset/core/config.py

@@ -41,7 +41,7 @@ def _init_device_info():
     """
     from mindspore import context
     from mindspore.parallel._auto_parallel_context import auto_parallel_context
-    from mindspore.parallel._utils import _get_global_rank, _get_device_num
+    from mindspore.parallel._utils import _get_global_rank
     if context.get_context("device_target") == "GPU":
         rank_id = _get_global_rank()
         parallel_mode = auto_parallel_context().get_parallel_mode()
@@ -53,11 +53,15 @@ def _init_device_info():
                     rank_id = cuda_id
         _config.set_rank_id(rank_id)
     elif context.get_context("device_target") == "Ascend":
-        rank_id = _get_global_rank()
-        device_num = _get_device_num()
-        # Ascend only support multi-process scenario
-        if device_num > 1:
-            _config.set_rank_id(rank_id)
+        # Ascend is a special scenario, we'd better get rank info from env
+        env_rank_size = os.getenv("RANK_SIZE", None)
+        env_rank_id = os.getenv("RANK_ID", None)
+        if env_rank_size and env_rank_id:
+            # Ascend only support multi-process scenario
+            rank_size = int(env_rank_size.strip())
+            rank_id = int(env_rank_id.strip())
+            if rank_size > 1:
+                _config.set_rank_id(rank_id)
 
 
 def set_seed(seed):