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Date: Fri, 30 Jun 2017 23:10:01 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>, Jan Kara <jack@suse.cz>,
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        Peter Zijlstra <peterz@infradead.org>,
        "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        Eric Biederman <ebiederm@xmission.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>, Pavel Machek <pavel@ucw.cz>,
        Andreas Mohr <andi@lisas.de>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCHv3 2/5] printk: introduce printing kernel thread
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On (06/30/17 15:16), Petr Mladek wrote:
[..]
>
> I wonder if I could add some counter into task_struct.
> It might be configurable. I am not sure if people would
> want this enabled on production systems where the level
> of messages should be lower anyway.

I don't think it really matters which one of the tasks has issued way
too many printk()-s. it's the state of the logbuf that matters after
all. was it one task or 5 tasks, or 15 that pushed logbuf far ahead of
console_seq, we need to throttle all of new printk() calls anyway.
just because logbuf is already too far and we need to give console a
chache to catch up. so let's activate throttling based on the logbuf
state (those seq numbers).

	-ss