diff --git a/src/sched/idle.c b/src/sched/idle.c
index 4a5a2e2ca39ea5e3a18c32387a6654e09eb18d0b..bebf5bf468228180af26be31f5e91e07df5def28 100644
--- a/src/sched/idle.c
+++ b/src/sched/idle.c
@@ -40,6 +40,7 @@ NX_PRIVATE NX_Bool IdleTimer(NX_Timer *tm, void *arg)
 
 /**
  * system idle thread on per cpu.
+ * todo: idle线程低功耗处理。
  */
 NX_PRIVATE void IdleThreadEntry(void *arg)
 {