!13481 fix squeezenet 8p performance degradation by adjusting parameters.

From: @anzhengqi
Reviewed-by: @heleiwang,@liucunwei
Signed-off-by: @liucunwei

model_zoo/official/cv/squeezenet/src/dataset.py

@@ -125,11 +125,9 @@ def create_dataset_imagenet(dataset_path,
 
     if device_num == 1:
         data_set = ds.ImageFolderDataset(dataset_path,
-                                         num_parallel_workers=8,
                                          shuffle=True)
     else:
         data_set = ds.ImageFolderDataset(dataset_path,
-                                         num_parallel_workers=8,
                                          shuffle=True,
                                          num_shards=device_num,
                                          shard_id=rank_id)
@@ -162,11 +160,10 @@ def create_dataset_imagenet(dataset_path,
     type_cast_op = C2.TypeCast(mstype.int32)
 
     data_set = data_set.map(operations=type_cast_op,
-                            input_columns="label",
-                            num_parallel_workers=8)
+                            input_columns="label")
     data_set = data_set.map(operations=trans,
                             input_columns="image",
-                            num_parallel_workers=8)
+                            num_parallel_workers=10)
 
     # apply batch operations
     data_set = data_set.batch(batch_size, drop_remainder=True)