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Date: Fri, 3 Nov 2017 07:54:56 -0400
From: Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH v3] printk: Add console owner and waiter logic to load
 balance console writes
Message-ID: <20171103075456.15cd811e@vmware.local.home>
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References: <20171102134515.6eef16de@gandalf.local.home>
	<82a3df5e-c8ad-dc41-8739-247e5034de29@suse.cz>
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	<20171103075404.14f9058a@vmware.local.home>
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To: John Hubbard <jhubbard@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>, LKML <linux-kernel@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>, 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>, Petr Mladek <pmladek@suse.com>, Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, "yuwang.yuwang" <yuwang.yuwang@alibaba-inc.com>, 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>

On Fri, 3 Nov 2017 07:54:04 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> The new waiter gets set only if there isn't already a waiter *and*
> there is an owner that is not current (and with the printk_safe_enter I
> don't think that is even needed).
> 
> +				while (!READ_ONCE(console_waiter))
> +					cpu_relax();

I still need to fix the patch. I cut and pasted the bad version. This
should have been:

	while (READ_ONCE(console_waiter))
		cpu_relax();

-- Steve

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