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Date: Tue, 03 Jul 2012 14:41:02 +0800
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
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To: Fengguang Wu <fengguang.wu@intel.com>
CC: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: kvm segfaults and bad page state in 3.4.0
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Hi Fengguang,

I can reproduce this bug in my test case, and have posted
a patch to fix it which can found at:
http://marc.info/?l=linux-mm&m=134129723504527&w=2

Could you please try it?

On 06/04/2012 07:46 PM, Fengguang Wu wrote:
> Hi,
> 
> I'm running lots of kvm instances for doing kernel boot tests.
> Unfortunately the test system itself is not stable enough, I got scary
> errors in both kvm and the host kernel. Like this. 
> 
> [294025.795382] kvm used greatest stack depth: 2896 bytes left
> [310388.622083] kvm[1864]: segfault at c ip 00007f498e9f6a81 sp 00007f4994b9fca0 error 4 in kvm[7f498e960000+33b000]
> [310692.050589] kvm[4332]: segfault at 10 ip 00007fca662620b9 sp 00007fca70472af0 error 6 in kvm[7fca661cc000+33b000]
> [312608.950120] kvm[18931]: segfault at 8 ip 00007f95962a10a5 sp 00007f959d777170 error 4 in kvm[7f959620b000+33b000]
> [312622.941640] kvm[19123]: segfault at 10 ip 00007f406f5580b9 sp 00007f4077d8b350 error 6 in kvm[7f406f4c2000+33b000]
> [313917.860951] kvm[28789]: segfault at c ip 00007f718f4dfa81 sp 00007f7198459520 error 4 in kvm[7f718f449000+33b000]
> [313919.177192] kvm used greatest stack depth: 2864 bytes left
> [314061.390945] kvm used greatest stack depth: 2208 bytes left
> [327479.676068] BUG: Bad page state in process kvm  pfn:59ac9