[CI/Build] Also check DP in benchmarks throughput script (#23038)

Co-authored-by: Simon Mo <simon.mo@hey.com>

benchmarks/benchmark_throughput.py

@@ -597,8 +597,8 @@ def validate_args(args):
     # https://github.com/vllm-project/vllm/issues/16222
     if args.data_parallel_size > 1:
         raise ValueError(
-            "Data parallel is not supported in offline benchmark, \
-            please use benchmark serving instead"
+            "Data parallel is not supported in offline benchmark, "
+            "please use benchmark serving instead"
         )
 
 

vllm/benchmarks/throughput.py

@@ -434,6 +434,14 @@ def validate_args(args):
     if args.backend == "mii" and args.tokenizer != args.model:
         raise ValueError(
             "Tokenizer must be the same as the model for MII backend.")
+    
+    # --data-parallel is not supported currently.
+    # https://github.com/vllm-project/vllm/issues/16222
+    if args.data_parallel_size > 1:
+        raise ValueError(
+            "Data parallel is not supported in offline benchmark, "
+            "please use benchmark serving instead"
+        )
 
 
 def add_cli_args(parser: argparse.ArgumentParser):