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Date: Wed, 11 Dec 2013 11:55:15 +0800
From: Xishi Qiu <qiuxishi@huawei.com>
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To: "H. Peter Anvin" <hpa@zytor.com>
CC: Yinghai Lu <yinghai@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        the arch/x86 maintainers <x86@kernel.org>, Linn Crosetto <linn@hp.com>,
        Pekka Enberg <penberg@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux MM <linux-mm@kvack.org>
Subject: Re: [PATCH] mm,x86: fix span coverage in e820_all_mapped()
References: <52A6D9B0.7040506@huawei.com> <CAE9FiQUd+sU4GEq0687u8+26jXJiJVboN90+L7svyosmm+V1Rg@mail.gmail.com> <52A7C16A.9040106@huawei.com> <52A7D415.6010908@zytor.com>
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On 2013/12/11 10:55, H. Peter Anvin wrote:

> On 12/10/2013 05:35 PM, Xishi Qiu wrote:
>>
>> In this case, old code is right, but I discuss in another one that
>> you wrote above.
>>
> 
> So is there a problem or not?  I have lost track...
> 

I think there is a problem.
e.g.
[start, end)=[8, 12), and [A, B)=[0, 10), [B, C)=[10,20),
then e820_all_mapped() will return 1, it spans two regions.

Thanks,
Xishi Qiu

> 	-hpa
> 
> 
> 
>