Use logger in accelerator (#3682)

* Use logger in accelerator

* Handle pre-build cases

* Explain possible import failure

accelerator/real_accelerator.py

@@ -4,6 +4,13 @@
 # DeepSpeed Team
 import os
 
+try:
+    # Importing logger currently requires that torch is installed, hence the try...except
+    # TODO: Remove logger dependency on torch.
+    from deepspeed.utils import logger as accel_logger
+except ImportError as e:
+    accel_logger = None
+
 try:
     from accelerator.abstract_accelerator import DeepSpeedAccelerator as dsa1
 except ImportError as e:
@@ -99,14 +106,16 @@ def get_accelerator():
         # XPU_Accelerator is already imported in detection stage
         ds_accelerator = XPU_Accelerator()
     _validate_accelerator(ds_accelerator)
-    print(f"Setting ds_accelerator to {ds_accelerator._name} ({ds_set_method})")
+    if accel_logger is not None:
+        accel_logger.info(f"Setting ds_accelerator to {ds_accelerator._name} ({ds_set_method})")
     return ds_accelerator
 
 
 def set_accelerator(accel_obj):
     global ds_accelerator
     _validate_accelerator(accel_obj)
-    print(f"Setting ds_accelerator to {accel_obj._name} (model specified)")
+    if accel_logger is not None:
+        accel_logger.info(f"Setting ds_accelerator to {accel_obj._name} (model specified)")
     ds_accelerator = accel_obj
 
 
@@ -114,10 +123,10 @@ def set_accelerator(accel_obj):
 -----------[code] test_get.py -----------
 from deepspeed.accelerator import get_accelerator
 my_accelerator = get_accelerator()
-print(f'{my_accelerator._name=}')
-print(f'{my_accelerator._communication_backend=}')
-print(f'{my_accelerator.HalfTensor().device=}')
-print(f'{my_accelerator.total_memory()=}')
+logger.info(f'{my_accelerator._name=}')
+logger.info(f'{my_accelerator._communication_backend=}')
+logger.info(f'{my_accelerator.HalfTensor().device=}')
+logger.info(f'{my_accelerator.total_memory()=}')
 -----------[code] test_get.py -----------
 
 ---[output] python test_get.py---------
@@ -131,16 +140,16 @@ my_accelerator.total_memory()=34089730048
 -----------[code] test_set.py -----------
 from deepspeed.accelerator.cuda_accelerator import CUDA_Accelerator
 cu_accel = CUDA_Accelerator()
-print(f'{id(cu_accel)=}')
+logger.info(f'{id(cu_accel)=}')
 from deepspeed.accelerator import set_accelerator, get_accelerator
 set_accelerator(cu_accel)
 
 my_accelerator = get_accelerator()
-print(f'{id(my_accelerator)=}')
-print(f'{my_accelerator._name=}')
-print(f'{my_accelerator._communication_backend=}')
-print(f'{my_accelerator.HalfTensor().device=}')
-print(f'{my_accelerator.total_memory()=}')
+logger.info(f'{id(my_accelerator)=}')
+logger.info(f'{my_accelerator._name=}')
+logger.info(f'{my_accelerator._communication_backend=}')
+logger.info(f'{my_accelerator.HalfTensor().device=}')
+logger.info(f'{my_accelerator.total_memory()=}')
 -----------[code] test_set.py -----------