栈接近栈尾地址意义在哪

#ifdef RT_USING_OVERFLOW_CHECK
static void _rt_scheduler_stack_check(struct rt_thread thread)
{
RT_ASSERT(thread != RT_NULL);
#if defined(ARCH_CPU_STACK_GROWS_UPWARD)
if (((rt_uint8_t *)((rt_ubase_t)thread->stack_addr + thread->stack_size - 1)) != '#' ||
#else
if (*((rt_uint8_t *)thread->stack_addr) != '#' ||
#endif
(rt_ubase_t)thread->sp <= (rt_ubase_t)thread->stack_addr ||
(rt_ubase_t)thread->sp >
(rt_ubase_t)thread->stack_addr + (rt_ubase_t)thread->stack_size)
{
rt_ubase_t level;
rt_kprintf("thread:%s stack overflow\n", thread->name);
#ifdef RT_USING_FINSH
{
extern long list_thread(void);
list_thread();
}
#endif
level = rt_hw_interrupt_disable();
while (level);
}
#if defined(ARCH_CPU_STACK_GROWS_UPWARD)
else if ((rt_ubase_t)thread->sp > ((rt_ubase_t)thread->stack_addr + thread->stack_size))
{
rt_kprintf("warning: %s stack is close to the top of stack address.\n",
thread->name);
}
#else
else if ((rt_ubase_t)thread->sp <= ((rt_ubase_t)thread->stack_addr + 32))
{
rt_kprintf("warning: %s stack is close to end of stack address.\n",
thread->name);
}
#endif
}
#endif
rtt 3.1.4版本，产品运行多月后，发生了两个狂飙之后的异常打印
“stack is close to end of stack address”。

看代码，是系统清除显然用完的提示。

开发调试时一直在线程使用率，开发调试中压根就不会出现这种情况

已经出去的产品，因为狂打印这个日志，让系统处于半死不死状态
所以，或者不如不打印打印，或者一次让整个系统重新开始