[dm-devel] Serial console is causing system lock-up

[John Ogness]

On 2019-03-07, Sergey Senozhatsky <sergey.senozhatsky.work at gmail.com> wrote:
>>> If the serial console is a really slow one and we have a CPU in
>>> atomic context spinnig on prb_lock, while the prb_lock is always
>>> acquired by other CPUs, then it may look like a lock-up scenario.
>> 
>> When the console is constantly printing messages, I wouldn't say that
>> looks like a lock-up scenario. It looks like the system is busy
>> printing critical information to the console (which it is).
>
> What if we have N tasks/CPUs calling printk() simultaneously?

Then they take turns printing their messages to the console, spinning
until they get their turn. This still is not and does not look like a
lock-up. But I think you already know this, so I don't understand the
reasoning behind asking the question. Maybe you could clarify what you
are getting at.

John Ogness