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Date: Mon, 18 Dec 2017 22:39:48 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>, Tejun Heo <tj@kernel.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Jan Kara <jack@suse.cz>, Andrew Morton <akpm@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Rafael Wysocki <rjw@rjwysocki.net>, Pavel Machek <pavel@ucw.cz>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCHv6 00/12] printk: introduce printing kernel thread
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On (12/18/17 14:31), Petr Mladek wrote:
> On Mon 2017-12-18 18:36:15, Sergey Senozhatsky wrote:
> > On (12/15/17 10:08), Petr Mladek wrote:
> > 1) it opens both soft and hard lockup vectors
> > 
> >    I see *a lot* of cases when CPU that call printk in a loop does not
> >    end up flushing its messages. And the problem seems to be - preemption.
> > 
> > 
> >   CPU0						CPU1
> > 
> >   for_each_process_thread(g, p)
> >     printk()
> 
> You print one message for each process in a tight loop.
> Is there a code like this?

um... show_state() -> show_state_filter()?
which prints million times more info than a single line per-PID.

	-ss