Fix data parallel perf regression (#6183)

python/sglang/srt/managers/data_parallel_controller.py

@@ -17,13 +17,13 @@ import logging
 import multiprocessing as mp
 import signal
 import threading
+import time
 from enum import Enum, auto
 
 import psutil
 import setproctitle
 import zmq
 
-from sglang.srt.disaggregation.utils import DisaggregationMode
 from sglang.srt.layers.dp_attention import compute_dp_attention_world_info
 from sglang.srt.managers.io_struct import (
     TokenizedEmbeddingReqInput,
@@ -158,7 +158,7 @@ class DataParallelController:
         # This thread cannot be closed because otherwise the `kill_itself_when_parent_died`
         # function in scheduler.py will kill the scheduler.
         while True:
-            pass
+            time.sleep(30 * 24 * 3600)
 
     def launch_dp_attention_schedulers(self, server_args, port_args):
         self.launch_tensor_parallel_group(server_args, port_args, 0, None)