From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: Serial console is causing system lock-up
Date: Thu, 7 Mar 2019 17:25:09 +0900
Message-ID: <20190307082509.GA1925@jagdpanzerIV>
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To: John Ogness <john.ogness@linutronix.de>
Cc: Petr Mladek <pmladek@suse.com>, Nigel Croxon <ncroxon@redhat.com>, "Theodore Y. Ts'o" <tytso@mit.edu>, Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Steven Rostedt <rostedt@goodmis.org>, Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, dm-devel@redhat.com, Mikulas Patocka <mpatocka@redhat.com>, linux-serial@vger.kernel.org
List-Id: linux-serial@vger.kernel.org

On (03/07/19 09:17), John Ogness 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?

	-ss