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Date: Mon, 23 Apr 2018 07:36:03 -0400
From: Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH] printk: Ratelimit messages printed by console drivers
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To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org, Peter Zijlstra <peterz@infradead.org>, Jan Kara <jack@suse.cz>, Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>, Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org, Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

On Mon, 23 Apr 2018 12:32:32 +0200
Petr Mladek <pmladek@suse.com> wrote:

> > Really?
> > 
> > 
> >   console_trylock_spinning(); /* console_owner now equals current */  
> 
> No, console_trylock_spinning() does not modify console_owner. The
> handshake is done using console_waiter variable.

Ug, you're right. Somehow when I looked at where console_owner was set
"console_lock_spinning_enabled" I saw it as "console_trylock_spinning".

This is what I get when I'm trying to follow three threads at the same
time :-/

> 
> console_owner is really set only between:
> 
>     console_lock_spinning_enable()
>     console_lock_spinning_disable_and_check()
> 
> and this entire section is called with interrupts disabled.

OK, I agree with you now. Although, one hour may still be too long.

-- Steve