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Subject: Re: [PATCH -next] panic: complete the flush of the hard deadlock log
 messages to the serial port
From:   "xuqiang (M)" <xuqiang36@huawei.com>
To:     Andrew Morton <akpm@linux-foundation.org>
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在 2020/11/24 11:22, xuqiang (M) 写道:
>
> 在 2020/11/24 3:52, Andrew Morton 写道:
>> On Mon, 23 Nov 2020 13:13:59 +0000 Xu Qiang <xuqiang36@huawei.com> 
>> wrote:
>>
>>> when hardlockup_all_cpu_backtrace is on, and there are
>>> a large number of cores in the system, it takes
>>> a long time to output the hard deadlock logs of all cores
>>> to the serial port. When the console_flush_on_panic function
>>> in panic is executed, console_locked is still held.
>>> As a result, garbled characters are displayed in the serial port log.
>>>
>>> To solve this problem, wait for a maximum of 10s for the serial port
>>> to be released before console_flush_on_panic.
>> Wouldn't it be better to wait until all the printing of all those
>> backtraces has completed?
>>
>>
>> .
>
> The fear that there may be some unexpected abnormal situation,
>
> resulting in the serial port has been occupied without release.
>
>
> Thanks
>
>         Xu.
>
Hi, Are there any other questions about this patch?


Thanks

         Xu.