Update reduce.py

reduce.py

@@ -8,7 +8,7 @@ def init_process():
 def example_reduce():
     tensor = torch.tensor([dist.get_rank()] * 4, dtype=torch.float32).cuda()
     print(f"Before reduce on rank {dist.get_rank()}: {tensor}")
-    dist.all_reduce(tensor, op=dist.ReduceOp.SUM)
+    dist.reduce(tensor, dst=0, op=dist.ReduceOp.SUM)
     print(f"After reduce on rank {dist.get_rank()}: {tensor}")
 
 init_process()