From 07b4f262b7a7d486fe8e5f462a27c7a19ebfef89 Mon Sep 17 00:00:00 2001
From: fzyzcjy <5236035+fzyzcjy@users.noreply.github.com>
Date: Tue, 19 May 2026 09:18:36 +0800
Subject: [PATCH] Set up the idle sleeper outside of the IPC channel
 initialization (#25713)

---
 python/sglang/srt/managers/scheduler.py | 26 ++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/python/sglang/srt/managers/scheduler.py b/python/sglang/srt/managers/scheduler.py
index 72b574cfb..58670f279 100644
--- a/python/sglang/srt/managers/scheduler.py
+++ b/python/sglang/srt/managers/scheduler.py
@@ -384,6 +384,7 @@ class Scheduler(
 
         # Init inter-process communication
         self.init_ipc_channels(port_args)
+        self.init_idle_sleeper()
 
         self.mm_receiver = None
         self.disagg_prefill_bootstrap_queue = None
@@ -726,7 +727,6 @@ class Scheduler(
 
     def init_ipc_channels(self, port_args: PortArgs):
         context = zmq.Context(2)
-        self.idle_sleeper = None
         self.send_metrics_from_scheduler = None
 
         if (
@@ -757,14 +757,6 @@ class Scheduler(
 
             self.send_to_tokenizer = SenderWrapper(send_to_tokenizer)
             self.send_to_detokenizer = SenderWrapper(send_to_detokenizer)
-
-            if self.server_args.sleep_on_idle:
-                self.idle_sleeper = IdleSleeper(
-                    [
-                        self.recv_from_tokenizer,
-                        self.recv_from_rpc,
-                    ]
-                )
         else:
             self.recv_from_tokenizer = None
             self.recv_from_rpc = None
@@ -779,6 +771,22 @@ class Scheduler(
                 context, zmq.PUSH, port_args.metrics_ipc_name, False
             )
 
+    def init_idle_sleeper(self) -> None:
+        if (
+            self.ps.pp_rank == 0
+            and self.ps.attn_tp_rank == 0
+            and self.ps.attn_cp_rank == 0
+            and self.server_args.sleep_on_idle
+        ):
+            self.idle_sleeper = IdleSleeper(
+                sockets=[
+                    self.recv_from_tokenizer,
+                    self.recv_from_rpc,
+                ],
+            )
+        else:
+            self.idle_sleeper = None
+
     def init_tokenizer(self):
         server_args = self.server_args
         self.is_generation = self.model_config.is_generation