From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [RFC PATCH v1 19/25] printk: introduce emergency messages
Date: Tue, 12 Mar 2019 11:58:47 +0900
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To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>, John Ogness <john.ogness@linutronix.de>, linux-kernel@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>, Steven Rostedt <rostedt@goodmis.org>, Daniel Wang <wonderfly@google.com>, Andrew Morton <akpm@linux-foundation.org>, Linus Torvalds <torvalds@linux-foundation.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Alan Cox <gnomes@lxorguk.ukuu.org.uk>, Jiri Slaby <jslaby@suse.com>, Peter Feiner <pfeiner@google.com>, linux-serial@vger.kernel.org, Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
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On (03/08/19 11:31), Petr Mladek wrote:
> Great catch!
> 
> I think that it is doable to guard the list using RCU.

I think console_sem is more than just list lock.

E.g. fb_flashcursor() - console_sem protects framebuffer from concurrent
modifications. And many other examples.

I think the last time we talked about it (two+ years ago) we counted
5 or 7 (don't remember exactly) different things which console_sem
does.

	-ss