Update data_loading.py

Lightning-AI · Oct 21, 2020 · 984c73f · 984c73f
1 parent 9f7662b
commit 984c73f
Showing 1 changed file with 3 additions and 4 deletions.
diff --git a/pytorch_lightning/trainer/data_loading.py b/pytorch_lightning/trainer/data_loading.py
@@ -112,12 +112,11 @@ def auto_add_sampler(self, dataloader: DataLoader, train: bool) -> DataLoader:
 
         if not is_dataloader or is_iterable_ds:
             return dataloader
-        need_dist_sampler = (self.use_ddp or self.use_ddp2 or self.use_horovod or self.use_tpu)
 
+        is_in_dist = self.use_ddp or self.use_ddp2 or self.use_horovod or self.use_tpu
+        need_dist_sampler = is_in_dist and not isinstance(dataloader.sampler, DistributedSampler)
         if self.replace_sampler_ddp and need_dist_sampler:
-            if isinstance(dataloader.sampler, DistributedSampler):
-                return dataloader
-            elif not isinstance(dataloader.sampler, (SequentialSampler, RandomSampler)):
+            if not isinstance(dataloader.sampler, (SequentialSampler, RandomSampler)):
                 raise MisconfigurationException(
                     'You seem to have configured a sampler in your DataLoader. This will be replaced '
                     ' by `DistributedSampler` since `replace_sampler_ddp` is True and you are using'