fix dali env bug

ppcls/data/dataloader/dali.py

@@ -230,7 +230,7 @@ def dali_dataloader(config, mode, device, seed=None):
         lower = ratio[0]
         upper = ratio[1]
 
-        if 'PADDLE_TRAINER_ID' in env and 'PADDLE_TRAINERS_NUM' in env:
+        if 'PADDLE_TRAINER_ID' in env and 'PADDLE_TRAINERS_NUM' in env and 'FLAGS_selected_gpus' in env:
             shard_id = int(env['PADDLE_TRAINER_ID'])
             num_shards = int(env['PADDLE_TRAINERS_NUM'])
             device_id = int(env['FLAGS_selected_gpus'])
@@ -282,7 +282,7 @@ def dali_dataloader(config, mode, device, seed=None):
     else:
         resize_shorter = transforms["ResizeImage"].get("resize_short", 256)
         crop = transforms["CropImage"]["size"]
-        if 'PADDLE_TRAINER_ID' in env and 'PADDLE_TRAINERS_NUM' in env and sampler_name == "DistributedBatchSampler":
+        if 'PADDLE_TRAINER_ID' in env and 'PADDLE_TRAINERS_NUM' in env and 'FLAGS_selected_gpus' in env and sampler_name == "DistributedBatchSampler":
             shard_id = int(env['PADDLE_TRAINER_ID'])
             num_shards = int(env['PADDLE_TRAINERS_NUM'])
             device_id = int(env['FLAGS_selected_gpus'])