diff --git a/arch/arm/src/armv7-a/arm_schedulesigaction.c b/arch/arm/src/armv7-a/arm_schedulesigaction.c
index 0ec3a1e15bb..ce765a33e77 100644
--- a/arch/arm/src/armv7-a/arm_schedulesigaction.c
+++ b/arch/arm/src/armv7-a/arm_schedulesigaction.c
@@ -274,7 +274,11 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
               tcb->irqcount++;
 
               /* Handle a possible race condition where the TCB was suspended
-               * just before we paused the other CPU.
+               * just before we paused the other CPU.  The critical section
+               * established above will prevent new threads from running on
+               * that CPU, but it will not guarantee that the running thread
+               * did not suspend itself (allowing any threads "assigned" to
+               * the CPU to run).
                */
 
               if (tcb->task_state != TSTATE_TASK_RUNNING)
diff --git a/arch/arm/src/armv7-m/up_schedulesigaction.c b/arch/arm/src/armv7-m/up_schedulesigaction.c
index 2ba672c55a7..fd248dc012b 100644
--- a/arch/arm/src/armv7-m/up_schedulesigaction.c
+++ b/arch/arm/src/armv7-m/up_schedulesigaction.c
@@ -310,7 +310,11 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
               tcb->irqcount++;
 
               /* Handle a possible race condition where the TCB was suspended
-               * just before we paused the other CPU.
+               * just before we paused the other CPU.  The critical section
+               * established above will prevent new threads from running on
+               * that CPU, but it will not guarantee that the running thread
+               * did not suspend itself (allowing any threads "assigned" to
+               * the CPU to run).
                */
 
               if (tcb->task_state != TSTATE_TASK_RUNNING)
diff --git a/arch/xtensa/src/common/xtensa_schedsigaction.c b/arch/xtensa/src/common/xtensa_schedsigaction.c
index b9c01ef5b52..42d309e9b57 100644
--- a/arch/xtensa/src/common/xtensa_schedsigaction.c
+++ b/arch/xtensa/src/common/xtensa_schedsigaction.c
@@ -283,7 +283,11 @@ void up_schedule_sigaction(struct tcb_s *tcb, sig_deliver_t sigdeliver)
               tcb->irqcount++;
 
               /* Handle a possible race condition where the TCB was suspended
-               * just before we paused the other CPU.
+               * just before we paused the other CPU.  The critical section
+               * established above will prevent new threads from running on
+               * that CPU, but it will not guarantee that the running thread
+               * did not suspend itself (allowing any threads "assigned" to
+               * the CPU to run).
                */
 
               if (tcb->task_state != TSTATE_TASK_RUNNING)