diff --git a/plugin/semisync/semisync_master_ack_receiver.cc b/plugin/semisync/semisync_master_ack_receiver.cc
index 7813807..cbef690 100644
--- a/plugin/semisync/semisync_master_ack_receiver.cc
+++ b/plugin/semisync/semisync_master_ack_receiver.cc
@@ -220,6 +220,7 @@ void Ack_receiver::run()
   fd_set read_fds;
   my_socket max_fd= INVALID_SOCKET;
   uint i;
+  time_t last_sched_ts= time(0);
 
   sql_print_information("Starting ack receiver thread");
 
@@ -294,6 +295,18 @@ void Ack_receiver::run()
       i++;
     }
     mysql_mutex_unlock(&m_mutex);
+
+    /*
+      Locking m_mutex in while will starve other threads.
+      Sleep 1us per second, so other threads can catch the m_mutex easily.
+    */
+    time_t now= time(0);
+    bool time_to_sched= ((ulonglong)(now - last_sched_ts) >= (ulonglong)(1));
+    if (time_to_sched)
+    {
+      last_sched_ts= time(0);
+      my_sleep(1);
+    }
   }
 end:
   sql_print_information("Stopping ack receiver thread");