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Date:   Tue, 23 Jan 2018 09:22:46 -0800
From:   Tejun Heo <tj@kernel.org>
To:     Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Petr Mladek <pmladek@suse.com>, akpm@linux-foundation.org,
        linux-mm@kvack.org, Cong Wang <xiyou.wangcong@gmail.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Peter Zijlstra <peterz@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Jan Kara <jack@suse.cz>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
        rostedt@home.goodmis.org, Byungchul Park <byungchul.park@lge.com>,
        Pavel Machek <pavel@ucw.cz>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
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Hello, Sergey.

On Wed, Jan 24, 2018 at 01:01:53AM +0900, Sergey Senozhatsky wrote:
> On (01/23/18 10:41), Steven Rostedt wrote:
> [..]
> > We can have more. But if printk is causing printks, that's a major bug.
> > And work queues are not going to fix it, it will just spread out the
> > pain. Have it be 100 printks, it needs to be fixed if it is happening.
> > And having all printks just generate more printks is not helpful. Even
> > if we slow them down. They will still never end.
> 
> Dropping the messages is not the solution either. The original bug report
> report was - this "locks up my kernel". That's it. That's all people asked
> us to solve.
> 
> With WQ we don't lockup the kernel, because we flush printk_safe in
> preemptible context. And people are very much expected to fix the
> misbehaving consoles. But that should not be printk_safe problem.

I really don't care as long as it's robust enough.

Thanks.

-- 
tejun