server: bench: enable flash_attn param

Author: phymbert

examples/server/bench/bench.py

@@ -268,6 +268,7 @@ def start_server_background(args):
     server_args.extend(['--defrag-thold', "0.1"])
     server_args.append('--cont-batching')
     server_args.append('--metrics')
+    server_args.append('--flash-attn')
     server_args.extend(['--log-format', "text"])
     args = [str(arg) for arg in [server_path, *server_args]]
     print(f"bench: starting server with: {' '.join(args)}")