linux-kernel - RE: [BUG] Threaded printk breaks early debugging

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Date:   Mon, 13 Jun 2022 16:11:19 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Petr Mladek' <pmladek@...e.com>,
        Sergey Senozhatsky <senozhatsky@...omium.org>
CC:     John Ogness <john.ogness@...utronix.de>,
        Peter Geis <pgwipeout@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "open list:ARM/Rockchip SoC..." <linux-rockchip@...ts.infradead.org>
Subject: RE: [BUG] Threaded printk breaks early debugging

From: Petr Mladek
> Sent: 13 June 2022 11:14
...
> Another interesting alternative is the Peter Zijlstra's mode
> where all messages are printed to the console "immediately".
> They are serialized only by the CPU-reentrant lock.
> 
> This mode is not good for production system. But it might
> be good for debugging. The good thing is that the behavior
> is well defined.

ISTM that all messages should be output (even if this means
that cpu spin waiting for a serial console) until userspace
has a chance to set an option to change the behaviour.

Oh, and can someone stop the distros hiding the console output.
I want to see the 'oops' traceback when I break the kernel!

	David

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