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Date:   Mon, 22 Jan 2018 19:36:11 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Tejun Heo <tj@kernel.org>, 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
Message-ID: <20180122103611.GD403@jagdpanzerIV>
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On (01/22/18 19:28), Sergey Senozhatsky wrote:
> On (01/22/18 17:56), Sergey Senozhatsky wrote:
> [..]
> > Assume the following,
> 
> But more importantly we are missing another huge thing - console_unlock().

IOW, not every console_unlock() is from vprintk_emit(). We can have
console_trylock() -> console_unlock() being from non-preemptible context,
etc. And then irq work to flush printk_safe -> printk_deferred all the time.

	-ss