From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tang Chen <tangchen@cn.fujitsu.com>
Subject: Re: [RESEND v2 PATCH 1/2] aio, memory-hotplug: Fix confliction when
 migrating and accessing ring pages.
Date: Mon, 17 Mar 2014 14:50:34 +0800
Message-ID: <53269B3A.4040900@cn.fujitsu.com>
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Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>, viro@zeniv.linux.org.uk,
	jmoyer@redhat.com, kosaki.motohiro@gmail.com,
	kosaki.motohiro@jp.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com,
	linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
	linux-kernel@vger.kernel.org, miaox@cn.fujitsu.com
To: Benjamin LaHaise <bcrl@kvack.org>
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On 03/14/2014 11:14 PM, Benjamin LaHaise wrote:
......
>> What about the following patch? It adds additional reference to protect the page
>> avoid being freed when we reading it.
>> ps.It is applied on linux-next(3-13).
>
> I think that's even worse than the spinlock approach since we'll end up
> bouncing around the struct page's cacheline in addition to spinlock we're
> going to end up taking anyways.
>

Hi Benjamin,

I'm sorry, I don't quite understand the cacheline problem you mentioned 
above.
Would you please explain more ?

Thanks.