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Subject: Re: [PATCH 3/3] lockdep: Use line-buffered printk() for lockdep
 messages.
References: <1541165517-3557-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp>
 <1541165517-3557-3-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp>
 <20181107151900.gxmdvx42qeanpoah@pathway.suse.cz>
 <20181108044510.GC2343@jagdpanzerIV>
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Message-ID: <9648a384-853c-942e-6a8d-80432d943aae@i-love.sakura.ne.jp>
Date: Thu, 8 Nov 2018 20:37:39 +0900
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Sender: owner-linux-mm@kvack.org
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To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>, Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, Dmitriy Vyukov <dvyukov@google.com>, Steven Rostedt <rostedt@goodmis.org>, Alexander Potapenko <glider@google.com>, Fengguang Wu <fengguang.wu@intel.com>, Josh Poimboeuf <jpoimboe@redhat.com>, LKML <linux-kernel@vger.kernel.org>, Linus Torvalds <torvalds@linux-foundation.org>, Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>, Will Deacon <will.deacon@arm.com>

On 2018/11/08 13:45, Sergey Senozhatsky wrote:
> So, can we just do the following? /* a sketch */
> 
> lockdep.c
> 	printk_safe_enter_irqsave(flags);
> 	lockdep_report();
> 	printk_safe_exit_irqrestore(flags);

If buffer size were large enough to hold messages from out_of_memory(),
I would like to use it for out_of_memory() because delaying SIGKILL
due to waiting for printk() to complete is not good. Surely we can't
hold all messages because amount from dump_tasks() is unpredictable.
Maybe we can hold all messages from dump_header() except dump_tasks().

But isn't it essentially same with
http://lkml.kernel.org/r/1493560477-3016-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
which Linus does not want?