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Date:   Tue, 12 Mar 2019 11:58:47 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
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>
Subject: Re: [RFC PATCH v1 19/25] printk: introduce emergency messages
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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